Android 10 相容性定義

一、簡介

本文檔列舉了裝置與 Android 10 相容必須滿足的要求。

「MUST」、「MUST NOT」、「REQUIRED」、「SHALL」、「SHALL NOT」、「SHOULD」、「SHOULD NOT」、「RECOMMENDED」、「MAY」和「OPTIONAL」的使用符合 IETF 標準RFC2119中定義的標準。

在本文檔中,「設備實現者」或「實現者」是指開發運行Android 10 的硬體/軟體解決方案的個人或組織。「設備實現者」或「實現者」是指如此開發的硬體/軟體解決方案。

要被視為與 Android 10 相容,裝置實作必須滿足此相容性定義中提出的要求,包括透過引用納入的任何文件。

如果第 10 節中所述的此定義或軟體測試是沉默的、不明確的或不完整的,則設備實現者有責任確保與現有實現的兼容性。

因此, Android 開源專案既是 Android 的參考實現,也是首選實現。強烈建議設備實現者最大程度地基於 Android 開源專案提供的「上游」原始程式碼來實現其實現。雖然假設某些組件可以替換為替代實現,但強烈建議不要遵循這種做法,因為通過軟體測試將變得更加困難。實作者有責任確保與標準 Android 實作完全行為相容,包括相容性測試套件。最後,請注意,本文檔明確禁止某些組件替換和修改。

本文檔中連結的許多資源直接或間接源自 Android SDK,並且在功能上與該 SDK 文件中的資訊相同。在任何情況下,如果本相容性定義或相容性測試套件與 SDK 文件不一致,則 SDK 文件被視為具有權威性。本文檔中連結資源中提供的任何技術細節均被視為本相容性定義的一部分。

1.1 文檔結構

1.1.1.設備類型的要求

第 2 部分包含適用於特定設備類型的所有要求。第 2 節的每個小節專用於特定的設備類型。

第 2 節之後的部分列出了所有普遍適用於任何 Android 裝置實現的其他要求。這些要求在本文檔中被稱為「核心要求」。

1.1.2.需求ID

需求 ID 是為 MUST 需求分配的。

  • 僅針對必須要求分配 ID。
  • 強烈建議的要求標記為 [SR],但未分配 ID。
  • ID 包括:設備類型 ID - 條件 ID - 要求 ID(例如 C-0-1)。

每個ID的定義如下:

  • 設備類型 ID(更多資訊請參閱2. 設備類型
    • C:核心(適用於任何 Android 裝置實現的要求)
    • H:Android手持設備
    • T:Android 電視設備
    • 答:Android 汽車實施
    • W:Android Watch 實現
    • Tab:Android平板電腦實現
  • 條件ID
    • 當要求是無條件時,該ID設定為0。
    • 當要求是有條件的時,為第一個條件分配1,並且在相同部分和相同設備類型內數字加1。
  • 需求ID
    • ID從1開始,在相同的部分和相同的條件下加1。

1.1.3.第 2 部分中的要求 ID

第 2 部分中的要求 ID 以對應的部分 ID 開頭,後面跟著上述要求 ID。

  • 第 2 部分中的 ID 包括:部分 ID/設備類型 ID - 條件 ID - 要求 ID(例如 7.4.3/A-0-1)。

2. 設備類型

雖然 Android 開源專案提供了可用於各種裝置類型和外形規格的軟體堆疊,但也有少數裝置類型擁有相對完善的應用程式分發生態系統。

本節介紹這些設備類型以及適用於每種設備類型的附加要求和建議。

所有不適合任何所描述的裝置類型的 Android 裝置實作仍然必須滿足本相容性定義其他部分中的所有要求。

2.1 設備配置

有關不同設備類型的硬體配置的主要差異,請參閱本節中隨後的特定於設備的要求。

2.2.手持設備要求

Android 手持裝置是指通常手持使用的 Android 裝置實現,例如 MP3 播放器、手機或平板電腦。

如果 Android 裝置實現滿足以下所有條件,則將其歸類為手持裝置:

  • 擁有提供行動性的電源,例如電池。
  • 螢幕物理對角線尺寸在 2.5 至 8 吋範圍內。

本節其餘部分的附加要求特定於 Android 手持裝置實作。

注意:不適用於 Android 平板電腦裝置的要求標示 *。

2.2.1.硬體

手持設備實現:

  • [ 7.1 .1.1/H-0-1] 必須擁有至少一台實體對角線尺寸至少為 2.5 吋的 Android 相容顯示器,並且每台 Android 相容顯示器必須滿足本文檔中所述的所有要求。
  • [ 7.1 .1.3/H-SR] 強烈建議為使用者提供更改顯示尺寸(螢幕密度)的能力。

如果手持裝置實作聲稱透過Configuration.isScreenHdr()支援高動態範圍顯示,則它們:

  • [ 7.1 .4.5/H-1-1] 必須通告對EGL_EXT_gl_colorspace_bt2020_pqEGL_EXT_surface_SMPTE2086_metadataEGL_EXT_surface_CTA861_3_metadataVK_EXT_swapchain_colorspaceVK_EXT_hdr_metadata

手持設備實現:

  • [ 7.1 .5/H-0-1] 必須包括對由上游 Android 開源程式碼實現的遺留應用程式相容模式的支援。也就是說,設備實作不得更改啟動相容模式的觸發器或閾值,且不得更改相容模式本身的行為。
  • [ 7.2 .1/H-0-1] 必須包含對第三方輸入法編輯器 (IME) 應用程式的支援。
  • [ 7.2 .3/H-0-3] 必須在所有提供主螢幕的 Android 相容顯示器上提供主頁功能。
  • [ 7.2 .3/H-0-4] 必須在所有 Android 相容顯示器上提供「後退」功能,並在至少一台 Android 相容顯示器上提供「最近使用」功能。
  • [ 7.2 .3/H-0-2] 必須將後退功能 ( KEYCODE_BACK ) 的正常按下事件和長按事件傳送至前台應用程式。這些事件不得由系統使用,並且可以由 Android 裝置外部觸發(例如連接到 Android 裝置的外部硬體鍵盤)。
  • [ 7.2 .4/H-0-1] 必須支援觸控螢幕輸入。
  • [ 7.2 .4/H-SR] 強烈建議啟動使用者選擇的輔助應用程序,即實現 VoiceInteractionService 的應用程序,或在長按KEYCODE_MEDIA_PLAY_PAUSEKEYCODE_HEADSETHOOK時處理ACTION_ASSIST的活動(如果前台活動沒有)處理那些長按事件。
  • [ 7.3 .1 /H-SR] 強烈建議包含 3 軸加速度計。

如果手持設備實現包括 3 軸加速計,則:

  • [ 7.3 .1/H-1-1] 必須能夠以至少 100 Hz 的頻率報告事件。

如果手持裝置實作包括 GPS/GNSS 接收器並透過android.hardware.location.gps功能標誌向應用程式報告該功能,則它們:

  • [ 7.3 .3/H-2-1] 一旦發現 GNSS 測量結果,即使尚未報告根據 GPS/GNSS 計算的位置,也必須立即報告。
  • [ 7.3 .3/H-2-2] 必須報告 GNSS 偽距和偽距率,在確定位置後的開闊天空條件下,當靜止或以小於 0.2 米每秒平方的加速度移動時,足以計算至少95 % 的時間,位置在20 公尺以內,速度在每秒0.2 公尺以內。

如果手持裝置實作包括 3 軸陀螺儀,則:

  • [ 7.3 .4/H-3-1] 必須能夠以至少 100 Hz 的頻率報告事件。
  • [ 7.3 .4/H-3-2] 必須能夠測量每秒高達 1000 度的方向變化。

可進行語音通話並在getPhoneType中指示除PHONE_TYPE_NONE以外的任何值的手持裝置實現:

  • [ 7.3 .8 /H] 應包括接近感測器。

手持設備實現:

  • [ 7.3 .11/H-SR] 建議支援 6 個自由度的位姿感測器。
  • [ 7.4 .3/H] 應包括對藍牙和藍牙 LE 的支援。

如果手持設備實施包括按流量計費的連接,則:

  • [ 7.4 .7/H-1-1] 必須提供資料保護模式。

如果手持設備實作包括使用CameraMetadata.REQUEST_AVAILABLE_CAPABILITIES_LOGICAL_MULTI_CAMERA列出功能的邏輯相機設備,則它們:

  • [ 7.5 .4/H-1-1] 預設必須具有正常視野 (FOV),且必須在 50 到 90 度之間。

手持設備實現:

  • [ 7.6 .1/H-0-1] 必須有至少 4 GB 的非揮發性儲存可用於應用程式私有資料(也稱為「/data」分割區)。
  • [ 7.6 .1/H-0-2] 當核心和使用者空間可用記憶體少於 1GB 時,必須為ActivityManager.isLowRamDevice()傳回「true」。

如果手持裝置實作聲明僅支援 32 位元 ABI:

  • [ 7.6 .1/H-1-1] 如果預設顯示器使用高達 qHD 的幀緩衝區解析度(例如 FWVGA),則核心和使用者空間可用的記憶體必須至少為 416MB。

  • [ 7.6 .1/H-2-1] 如果預設顯示器使用高達 HD+ 的幀緩衝區解析度(例如 HD、WSVGA),則核心和使用者空間可用的記憶體必須至少為 592MB。

  • [ 7.6 .1/H-3-1] 如果預設顯示器使用高達 FHD 的幀緩衝區解析度(例如 WSXGA+),則核心和使用者空間可用的記憶體必須至少為 896MB。

  • [ 7.6 .1/H-4-1] 如果預設顯示器使用高達 QHD 的幀緩衝區解析度(例如 QWXGA),則核心和使用者空間可用的記憶體必須至少為 1344MB。

如果手持設備實作聲明支援任何 64 位元 ABI(有或沒有任何 32 位元 ABI):

  • [ 7.6 .1/H-5-1] 如果預設顯示器使用高達 qHD 的幀緩衝區解析度(例如 FWVGA),則核心和使用者空間可用的記憶體必須至少為 816MB。

  • [ 7.6 .1/H-6-1] 如果預設顯示器使用高達 HD+ 的幀緩衝區解析度(例如 HD、WSVGA),則核心和使用者空間可用的記憶體必須至少為 944MB。

  • [ 7.6 .1/H-7-1] 如果預設顯示器使用高達 FHD 的幀緩衝區解析度(例如 WSXGA+),則核心和使用者空間可用的記憶體必須至少為 1280MB。

  • [ 7.6 .1/H-8-1] 如果預設顯示器使用高達 QHD 的幀緩衝區解析度(例如 QWXGA),則核心和使用者空間可用的記憶體必須至少為 1824MB。

請注意,上面的「核心和用戶空間可用的記憶體」是指除了已經專用於硬體組件(例如無線電、視訊等)的任何記憶體之外提供的記憶體空間,這些硬體元件在裝置實作上不受核心控制。

如果手持裝置實作包含小於或等於 1GB 可供核心和使用者空間使用的內存,則:

  • [ 7.6 .1/H-9-1] 必須聲明功能標誌android.hardware.ram.low
  • [ 7.6 .1/H-9-2] 必須具有至少 1.1 GB 的非揮發性儲存空間來儲存應用程式私有資料(也稱為「/data」分區)。

如果手持裝置實作包括可供核心和使用者空間使用的超過 1GB 的內存,則:

  • [ 7.6 .1/H-10-1] 必須有至少 4GB 的非揮發性儲存可用於應用程式私有資料(也稱為「/data」分割區)。
  • 應聲明功能標誌android.hardware.ram.normal

手持設備實現:

  • [ 7.6 .2/H-0-1] 不得提供小於 1 GiB 的應用程式共用儲存。
  • [ 7.7 .1/H] 應包括一個支援週邊模式的 USB 連接埠。

如果手持設備實作包括支援週邊模式的 USB 端口,則:

  • [ 7.7 .1/H-1-1] 必須實作 Android 開放附件 (AOA) API。

如果手持設備實作包括支援主機模式的 USB 端口,則它們:

手持設備實現:

  • [ 7.8 .1/H-0-1] 必須包括麥克風。
  • [ 7.8 .2/H-0-1] 必須有音訊輸出並聲明android.hardware.audio.output

如果手持裝置實現能夠滿足支援 VR 模式的所有效能要求並包括對其的支持,那麼它們:

  • [ 7.9 .1/H-1-1] 必須聲明android.hardware.vr.high_performance功能標誌。
  • [ 7.9 .1/H-1-2] 必須包含一個實作android.service.vr.VrListenerService應用程序,VR 應用程式可以透過android.app.Activity#setVrModeEnabled啟用該服務。

如果手持裝置實作包括主機模式下的一個或多個 USB-C 連接埠並實作(USB 音訊類別),除了第 7.7.2 節中的要求外,它們:

  • [ 7.8 .2.2/H-1-1] 必須提供以下 HID 程式碼的軟體映射:
功能對應情境行為
A HID 使用頁面:0x0C
HID 用法:0x0CD
核心鍵KEY_PLAYPAUSE
Android 鍵KEYCODE_MEDIA_PLAY_PAUSE
媒體播放輸入:短按
輸出:播放或暫停
輸入:長按
輸出:啟動語音指令
如果裝置被鎖定或其螢幕關閉,則傳送android.speech.action.VOICE_SEARCH_HANDS_FREE 。否則發送android.speech.RecognizerIntent.ACTION_WEB_SEARCH
來電輸入:短按
輸出:接受呼叫
輸入:長按
輸出:拒接來電
正在進行的通話輸入:短按
輸出:結束通話
輸入:長按
輸出:麥克風靜音或取消靜音
HID 使用頁面:0x0C
HID 用法:0x0E9
核心密鑰KEY_VOLUMEUP
Android 鍵VOLUME_UP
媒體播放、通話中輸入:短按或長按
輸出:增加系統或耳機音量
C HID 使用頁面:0x0C
HID 使用:0x0EA
核心密鑰KEY_VOLUMEDOWN
Android 鍵VOLUME_DOWN
媒體播放、通話中輸入:短按或長按
輸出:降低系統或耳機音量
D HID 使用頁面:0x0C
HID 用法:0x0CF
核心密鑰KEY_VOICECOMMAND
Android 按鍵KEYCODE_VOICE_ASSIST
全部。可以在任何情況下觸發。輸入:短按或長按
輸出:啟動語音指令
  • [ 7.8 .2.2/H-1-2] 必須在插頭插入時觸發ACTION_HEADSET_PLUG ,但只有在正確枚舉 USB 音訊介面和端點之後才能識別所連接終端的類型。

當偵測到 USB 音訊終端類型 0x0302 時,它們:

  • [ 7.8 .2.2/H-2-1] 必須廣播 Intent ACTION_HEADSET_PLUG,並將「麥克風」額外設定為 0。

當偵測到 USB 音訊終端類型 0x0402 時,它們:

  • [ 7.8 .2.2/H-3-1] 必須廣播 Intent ACTION_HEADSET_PLUG,並將「麥克風」額外設定為 1。

當 USB 週邊連接時呼叫 API AudioManager.getDevices() 時,它們:

  • [ 7.8 .2.2/H-4-1] 如果 USB 音訊終端類型欄位為 0x0302,則必須列出AudioDeviceInfo.TYPE_USB_HEADSET類型的裝置和角色 isSink()。

  • [ 7.8 .2.2/H-4-2] 如果 USB 音訊終端類型欄位為 0x0402,則必須列出 AudioDeviceInfo.TYPE_USB_HEADSET 類型的裝置和角色 isSink()。

  • [ 7.8 .2.2/H-4-3] 如果 USB 音訊終端類型欄位為 0x0402,則必須列出 AudioDeviceInfo.TYPE_USB_HEADSET 類型的裝置和角色 isSource()。

  • [ 7.8 .2.2/H-4-4] 如果 USB 音訊終端類型欄位為 0x603,則必須列出AudioDeviceInfo.TYPE_USB_DEVICE類型和角色 isSink() 的裝置。

  • [ 7.8 .2.2/H-4-5] 如果 USB 音訊終端類型欄位為 0x604,則必須列出 AudioDeviceInfo.TYPE_USB_DEVICE 類型和角色 isSource() 的裝置。

  • [ 7.8 .2.2/H-4-6] 如果 USB 音訊終端類型欄位為 0x400,則必須列出 AudioDeviceInfo.TYPE_USB_DEVICE 類型的裝置和角色 isSink()。

  • [ 7.8 .2.2/H-4-7] 如果 USB 音訊終端類型欄位為 0x400,則必須列出 AudioDeviceInfo.TYPE_USB_DEVICE 類型和角色 isSource() 的裝置。

  • [ 7.8 .2.2/H-SR] 強烈建議在連接 USB-C 音訊週邊時執行 USB 描述符枚舉、識別終端類型並在 1000 毫秒內廣播 Intent ACTION_HEADSET_PLUG。

2.2.2.多媒體

手持裝置實作必須支援以下音訊編碼和解碼格式,並使其可供第三方應用程式使用:

  • [ 5.1 /H-0-1] AMR-NB
  • [ 5.1 /H-0-2] AMR-WB
  • [ 5.1 /H-0-3] MPEG-4 AAC 設定檔 (AAC LC)
  • [ 5.1 /H-0-4] MPEG-4 HE AAC 設定檔 (AAC+)
  • [ 5.1 /H-0-5] AAC ELD(增強型低延遲 AAC)

手持設備實作必須支援以下視訊編碼格式並使其可供第三方應用程式使用:

  • [ 5.2 /H-0-1] H.264 AVC
  • [ 5.2 /H-0-2] VP8

手持設備實作必須支援以下視訊解碼格式並使其可供第三方應用程式使用:

  • [ 5.3 /H-0-1] H.264 AVC
  • [ 5.3 /H-0-2] H.265 HEVC
  • [ 5.3 /H-0-3] MPEG-4 SP
  • [ 5.3 /H-0-4] VP8
  • [ 5.3 /H-0-5] VP9

2.2.3.軟體

手持設備實現:

  • [ 3.2.3.1 /H-0-1] 必須有一個應用程式來處理 SDK 文件中所述的ACTION_GET_CONTENTACTION_OPEN_DOCUMENTACTION_OPEN_DOCUMENT_TREEACTION_CREATE_DOCUMENT意圖,並提供使用者使用DocumentsProvider API REE和ACTION_CREATE_DOCUMENT意圖,並提供使用者使用DocumentsProvider API
  • [ 3.4 .1/H-0-1] 必須提供android.webkit.Webview API 的完整實作。
  • [ 3.4 .2/H-0-1] 必須包含用於一般使用者 Web 瀏覽的獨立瀏覽器應用程式。
  • [ 3.8 .1/H-SR] 強烈建議實現一個支援應用程式內固定快捷方式、小部件和小部件功能的預設啟動器。
  • [ 3.8 .1/H-SR] 強烈建議實作一個預設啟動器,該啟動器可以透過ShortcutManager API 快速存取第三方應用程式提供的其他捷徑。
  • [ 3.8 .1/H-SR] 強烈建議包含一個顯示應用程式圖示徽章的預設啟動器應用程式。
  • [ 3.8 .2/H-SR] 強烈建議支援第三方應用程式小工具。
  • [ 3.8 .3/H-0-1] 必須允許第三方應用程式透過NotificationNotificationManager API 類別向使用者通知值得注意的事件。
  • [ 3.8 .3/H-0-2] 必須支援豐富的通知。
  • [ 3.8 .3/H-0-3] 必須支援平視通知。
  • [ 3.8 .3/H-0-4] 必須包含通知欄,使用戶能夠透過使用者功能(例如操作按鈕或所實現的控制面板)直接控制(例如回覆、暫停、關閉、封鎖)通知在 AOSP 中。
  • [ 3.8 .3/H-0-5] 必須在通知欄中顯示透過RemoteInput.Builder setChoices()提供的選項。
  • [ 3.8 .3/H-SR] 強烈建議在通知欄中顯示透過RemoteInput.Builder setChoices()提供的第一個選擇,而無需額外的使用者互動。
  • [ 3.8 .3/H-SR] 強烈建議當使用者展開通知欄中的所有通知時,在通知欄中顯示透過RemoteInput.Builder setChoices()提供的所有選項。
  • [ 3.8 .3.1/H-SR] 強烈建議顯示將Notification.Action.Builder.setContextual設定為true操作,並與Notification.Remoteinput.Builder.setChoices顯示的回復一致。
  • [ 3.8 .4/H-SR] 強烈建議在設備上實現助手來處理協助操作

如果手持設備實現支援輔助操作,則它們:

  • [ 3.8 .4/H-SR] 強烈建議使用長按HOME鍵作為啟動輔助應用程式的指定交互,如第 7.2.3 節所述。必須啟動使用者選擇的輔助應用程序,即實現VoiceInteractionService的應用程序,或處理ACTION_ASSIST意圖的活動。

如果 Android 手持裝置實現支援鎖定螢幕,則:

  • [ 3.8 .10/H-1-1] 必須顯示鎖定畫面通知,包括媒體通知範本。

如果手持裝置實現支援安全鎖定螢幕,則它們:

  • [ 3.9 /H-1-1] 必須實施 Android SDK 文件中定義的全部裝置管理策略。
  • [ 3.9 /H-1-2] 必須透過android.software.managed_users功能標誌聲明對託管配置文件的支持,除非設備配置為將自身報告為低 RAM 設備或分配內部 (不可移動)存儲作為共享存儲。

手持設備實現:

  • [ 3.10 /H-0-1] 必須支援第三方無障礙服務。
  • [ 3.10 /H-SR] 強烈建議在裝置上預先載入與 Switch Access 和 TalkBack(針對預先安裝文字轉語音引擎支援的語言)功能相當或超過對講開放中提供的輔助功能的輔助服務來源專案
  • [ 3.11 /H-0-1] 必須支援安裝第三方 TTS 引擎。
  • [ 3.11 /H-SR] 強烈建議包含支援裝置上可用語言的 TTS 引擎。
  • [ 3.13 /H-SR] 強烈建議包含快速設定 UI 元件。

如果 Android 手持裝置實現聲明FEATURE_BLUETOOTHFEATURE_WIFI支持,則:

  • [ 3.16 /H-1-1] 必須支援配套設備配對功能。

如果導航功能是作為螢幕上基於手勢的操作提供:

  • [ 7.2 .3/H] Home 功能的手勢辨識區域距螢幕底部的高度不應高於 32 dp。

如果手持裝置實現提供導航功能作為螢幕左右邊緣任意位置的手勢:

  • [ 7.2 .3/H-0-1] 導航功能的手勢區域每側的寬度必須小於 40 dp。預設情況下,手勢區域的寬度應為 24 dp。

2.2.4.性能和功率

  • [ 8.1 /H-0-1]一致的幀延遲。不一致的幀延遲或渲染幀延遲的發生頻率不得超過每秒 5 幀,且應低於每秒 1 幀。
  • [ 8.1 /H-0-2]使用者介面延遲。裝置實作必須透過在 36 秒內捲動 Android 相容性測試套件 (CTS) 定義的 10K 清單條目清單來確保低延遲使用者體驗。
  • [ 8.1 /H-0-3]任務切換。當多個應用程式已啟動時,啟動後重新啟動已執行的應用程式所用時間必須少於 1 秒。

手持設備實現:

  • [ 8.2 /H-0-1] 必須確保至少 5 MB/s 的順序寫入效能。
  • [ 8.2 /H-0-2] 必須確保至少 0.5 MB/s 的隨機寫入效能。
  • [ 8.2 /H-0-3] 必須確保至少 15 MB/s 的順序讀取效能。
  • [ 8.2 /H-0-4] 必須確保至少 3.5 MB/s 的隨機讀取效能。

如果手持設備實作包括改進 AOSP 中包含的設備電源管理的功能或擴展 AOSP 中包含的功能,則它們:

  • [ 8.3 /H-1-1] 必須提供使用者啟用和停用節電功能的功能。
  • [ 8.3 /H-1-2] 必須讓使用者顯示所有免於應用程式待機和 Doze 節能模式的應用程式。

手持設備實現:

  • [ 8.4 /H-0-1] 必須提供每個組件的電源配置文件,該配置文件定義每個硬體組件的電流消耗值以及組件隨著時間的推移造成的近似電池消耗,如Android 開源專案網站中所述。
  • [ 8.4 /H-0-2] 必須以毫安培小時 (mAh) 為單位報告所有功耗值。
  • [ 8.4 /H-0-3] 必須報告每個行程 UID 的 CPU 功耗。 Android開源專案透過uid_cputime核心模組實作來滿足要求。
  • [ 8.4 /H-0-4] 必須透過adb shell dumpsys batterystats shell 指令向應用程式開發人員提供此電量使用量。
  • [ 8.4 /H] 如果無法將硬體組件的電源使用歸因於應用程序,則應歸因於硬體組件本身。

如果手持裝置實作包括螢幕或視訊輸出,則它們:

2.2.5。安全模型

手持設備實現:

  • [ 9.1 /H-0-1] 必須允許第三方應用程式透過android.permission.PACKAGE_USAGE_STATS權限存取使用情況統計信息,並提供用戶可訪問的機制來授予或撤銷對此類應用程式的存取權限以響應android.settings.ACTION_USAGE_ACCESS_SETTINGS意圖。

手持裝置實現(*不適用於平板電腦):

  • [ 9.11 /H-0-2]* 必須使用隔離的執行環境來備份金鑰庫實作。
  • [ 9.11 /H-0-3]* 必須實作 RSA、AES、ECDSA 和 HMAC 加密演算法以及 MD5、SHA1 和 SHA-2 系列雜湊函數,以便在以下區域正確支援 Android 金鑰庫系統支援的演算法:與核心及以上運行的程式碼安全隔離。安全隔離必須阻止核心或使用者空間程式碼可能存取隔離環境的內部狀態的所有潛在機制,包括 DMA。上游 Android 開源專案 (AOSP) 透過使用Trusty實作來滿足此要求,但另一個基於 ARM TrustZone 的解決方案或第三方審查的基於適當管理程序的隔離的安全實作是替代選項。
  • [ 9.11 /H-0-4]* 必須在隔離執行環境中執行鎖定畫面驗證,並且僅在成功時才允許使用驗證綁定金鑰。鎖定螢幕憑證的儲存方式必須僅允許隔離的執行環境執行鎖定螢幕身份驗證。上游Android開源專案提供了Gatekeeper硬體抽象層(HAL)和Trusty,可以用來滿足這個需求。
  • [ 9.11 /H-0-5]* 必須支援金鑰證明,其中證明簽章金鑰受安全硬體保護並且簽章在安全硬體中執行。證明簽章金鑰必須在足夠多的裝置之間共用,以防止金鑰被用作裝置識別碼。滿足此要求的一種方法是共享相同的證明金鑰,除非給定 SKU 的生產量至少為 100,000 件。如果生產的 SKU 超過 100,000 個單位,則每 100,000 個單位可以使用不同的金鑰。

請注意,如果裝置實作已在早期 Android 版本上啟動,則此類裝置無需擁有由隔離執行環境支援的金鑰庫並支援金鑰證明,除非它聲明了android.hardware.fingerprint功能需要由隔離執行環境支援的金鑰庫。

當手持裝置實現支援安全鎖定螢幕時,它們:

  • [ 9.11 /H-1-1] 必須允許使用者選擇最短的睡眠逾時,即從解鎖狀態到鎖定狀態的轉換時間,為 15 秒或更短。
  • [ 9.11 /H-1-2] 必須提供使用者隱藏通知並停用除9.11.1 安全鎖定畫面中所述的主要驗證之外的所有形式的驗證的功能。 AOSP 滿足鎖定模式的要求。

如果手持裝置實作包含多個使用者且未聲明android.hardware.telephony功能標誌,則它們:

  • [ 9.5 /H-2-1] 必須支援受限設定文件,該功能允許設備所有者管理其他使用者及其在設備上的功能。透過受限設定文件,裝置擁有者可以快速設定單獨的環境供其他使用者工作,並能夠管理這些環境中可用的應用程式中的更細粒度的限制。

如果手持裝置實作包含多個使用者並聲明android.hardware.telephony功能標誌,則它們:

  • [ 9.5 /H-3-1] 不得支援受限設定文件,但必須與 AOSP 控制實作保持一致,以啟用/停用其他使用者存取語音呼叫和 SMS。

2.2.6.開發人員工具和選項相容性

手持裝置實現(*不適用於平板電腦):

  • [ 6.1 /H-0-1]* 必須支援 shell 指令cmd testharness

手持裝置實現(*不適用於平板電腦):

  • 完美
    • [ 6.1 /H-0-2]* 必須向 cmdline 符合perfetto 文件的 shell 使用者公開/system/bin/perfetto二進位檔案。
    • [ 6.1 /H-0-3]* perfetto 二進位檔案必須接受符合perfetto 文件中定義的架構的 protobuf 配置作為輸入。
    • [ 6.1 /H-0-4]* perfetto 二進位檔案必須寫入符合perfetto 文件中定義的模式的 protobuf 追蹤作為輸出。
    • [ 6.1 /H-0-5]* 必須透過 perfetto 二進位檔案至少提供perfetto 文件中所述的資料來源。

2.3.電視需求

An Android Television device refers to an Android device implementation that is an entertainment interface for consuming digital media, movies, games, apps, and/or live TV for users sitting about ten feet away (a “lean back” or “10-foot user介面").

如果 Android 裝置實現滿足以下所有條件,則將其歸類為電視:

  • 提供了一種機制來遠端控制可能距離使用者十英尺遠的顯示器上呈現的使用者介面。
  • 擁有對角線長度大於 24 吋的嵌入式螢幕顯示器,或包含視訊輸出端口,例如 VGA、HDMI、DisplayPort 或用於顯示的無線連接埠。

本節其餘部分的附加要求特定於 Android Television 裝置實作。

2.3.1.硬體

電視設備實現:

  • [ 7.2 .2/T-0-1] 必須支援方向鍵
  • [ 7.2 .3/T-0-1] 必須提供主頁和返回功能。
  • [ 7.2 .3/T-0-2] 必須將 Back 函數 ( KEYCODE_BACK ) 的正常按下事件和長按事件傳送到前台應用程式。
  • [ 7.2 .6.1/T-0-1] 必須包含對遊戲控制器的支援並聲明android.hardware.gamepad功能標誌。
  • [ 7.2 .7/T] 應提供一個遙控器,使用者可透過此遙控器存取非觸控導航核心導航鍵輸入。

如果電視設備實現包括 3 軸陀螺儀,則它們:

  • [ 7.3 .4/T-1-1] 必須能夠以至少 100 Hz 的頻率報告事件。
  • [ 7.3 .4/T-1-2] 必須能夠測量每秒高達 1000 度的方向變化。

電視設備實現:

  • [ 7.4 .3/T-0-1] 必須支援藍牙和藍牙 LE。
  • [ 7.6 .1/T-0-1] 必須有至少 4 GB 的非揮發性儲存可用於應用程式私有資料(也稱為「/data」分割區)。

如果電視設備實現包括支援主機模式的 USB 端口,則它們:

  • [ 7.5 .3/T-1-1] 必須支援透過此 USB 連接埠連接但不一定始終連接的外部攝影機。

如果電視設備實現是 32 位元:

  • [ 7.6 .1/T-1-1] 如果使用以下任何密度,則核心和使用者空間可用的記憶體必須至少為 896MB:

    • 小/普通螢幕上 400dpi 或更高
    • 大螢幕上 xhdpi 或更高
    • 超大螢幕上的 tvdpi 或更高

如果電視設備實現是 64 位元:

  • [ 7.6 .1/T-2-1] 如果使用以下任何密度,則核心和使用者空間可用的記憶體必須至少為 1280MB:

    • 小/普通螢幕上 400dpi 或更高
    • 大螢幕上 xhdpi 或更高
    • 超大螢幕上的 tvdpi 或更高

請注意,上面的「核心和用戶空間可用的記憶體」是指除了已經專用於硬體組件(例如無線電、視訊等)的任何記憶體之外提供的記憶體空間,這些硬體元件在裝置實作上不受核心控制。

電視設備實現:

  • [ 7.8 .1/T] 應包括麥克風。
  • [ 7.8 .2/T-0-1] 必須有音訊輸出並聲明android.hardware.audio.output

2.3.2.多媒體

電視設備實作必須支援以下音訊編碼和解碼格式,並使其可供第三方應用程式使用:

  • [ 5.1 /T-0-1] MPEG-4 AAC 設定檔 (AAC LC)
  • [ 5.1 /T-0-2] MPEG-4 HE AAC 設定檔 (AAC+)
  • [ 5.1 /T-0-3] AAC ELD(增強型低延遲 AAC)

電視設備實作必須支援以下視訊編碼格式並使其可供第三方應用程式使用:

  • [ 5.2 /T-0-1] H.264
  • [ 5.2 /T-0-2] VP8

電視設備實現:

  • [ 5.2 .2/T-SR] 強烈建議支援每秒 30 幀的 720p 和 1080p 解析度影片的 H.264 編碼。

電視設備實作必須支援以下視訊解碼格式並使其可供第三方應用程式使用:

電視設備實作必須支援 MPEG-2 解碼,如第 5.3.1 節所述,標準視訊幀率和解析度高達並包括:

  • [ 5.3.1 /T-1-1] 高清 1080p,每秒 29.97 幀,具有 Main Profile High Level。
  • [ 5.3.1 /T-1-2] HD 1080i,每秒 59.94 幀,具有 Main Profile High Level。它們必須對隔行掃描 MPEG-2 影片進行去隔行處理,並將其提供給第三方應用程式。

電視設備實施必須支援H.264解碼,如第5.3.4節所述,以標準的視訊框架速率和決議為止,直到和包括:

  • [ 5.3.4 /t-1-1] HD 1080p,每秒60幀,基線概況
  • [ 5.3.4 /t-1-2] HD 1080p,每秒60幀,主配置
  • [ 5.3.4 /t-1-3] HD 1080p以每秒60幀的速度為4.2

H.265硬體解碼器的電視設備實現必須支援H.265解碼,如第5.3.5節所述,以標準的視訊幀速率和解析度為止,直到並包括:

  • [ 5.3.5 /t-1-1]高清1080p,每秒60幀,主配置級4.1

如果使用H.265硬體解碼器支援H.265解碼和UHD解碼設定檔的電視設備實現,則它們:

  • [ 5.3.5 /t-2-1]必須以每秒60幀的速度支援UHD解碼設定文件,而Main10等級5 Main Tier設定檔。

電視設備實現必須支援VP8解碼,如第5.3.6節所述,以標準的視訊框架速率和解決方案為止,直到和包括:

  • [ 5.3.6 /t-1-1] HD 1080p以60幀每秒解碼設定檔

使用VP9硬體解碼器的電視設備實作必須支援VP9解碼,如第5.3.7節所述,以標準的視訊框架速率和解析度為止,直到:

  • [ 5.3.7 /t-1-1]高清1080p,每秒60幀,設定檔0(8位元顏色深度)

如果用VP9硬體解碼器實現電視設備支援VP9解碼和UHD解碼配置文件,則它們:

  • [ 5.3.7 /t-2-1]必須以每秒60幀為單位(8位元顏色深度)以60幀的速度支援UHD解碼設定檔。
  • 強烈建議[ 5.3.7 /t-2-1]以每秒60幀的速度支撐UHD解碼曲線,並使用設定檔2(10位元顏色深度)。

電視設備實現:

  • [ 5.5 /t-0-1]必須包括對系統主量的支援和數位音訊輸出量衰減對支援的輸出的支持,除了壓縮音訊傳遞輸出(在設備上未完成音訊解碼)。

如果電視設備實現沒有內建顯示屏,而是支援透過HDMI連接的外部顯示,則它們:

  • [ 5.8 /t-0-1]必須設定HDMI輸出模式以選擇可使用50Hz或60Hz刷新率支援的最大解析度。
  • 強烈建議[ 5.8 /t-SR]提供使用者可設定的HDMI刷新率選擇器。
  • [ 5.8 ]應將HDMI輸出模式更新率設定為50Hz或60Hz,取決於該裝置出售的區域的視訊更新率。

如果電視設備實現沒有內建顯示屏,而是支援透過HDMI連接的外部顯示,則它們:

  • [ 5.8 /t-1-1]必須支援HDCP 2.2。

如果電視設備實現不支援UHD解碼,而是支援透過HDMI連接的外部顯示,則它們:

  • [ 5.8 /t-2-1]必須支援HDCP 1.4

2.3.3.軟體

電視設備實現:

  • [ 3 /t-0-1]必須聲明功能android.software.leanbackandroid.hardware.type.television
  • [ 3.4 .1/t-0-1]必須提供android.webkit.Webview API的完整實作。

如果Android電視裝置實現支援鎖定螢幕,則應:

  • [ 3.8 .10/T-1-1]必須顯示鎖定畫面通知,包括媒體通知範本。

電視設備實現:

如果電視設備實作報告了功能android.hardware.audio.output ,則它們:

  • 強烈建議使用[ ​​3.11 /t-SR]包括支撐設備上可用語言的TTS引擎。
  • [ 3.11 /T-1-1]必須支援安裝第三方TTS引擎。

電視設備實現:

  • [ 3.12 /T-0-1]必須支援電視輸入框架。

2.3.4.性能和力量

  • [ 8.1 /t-0-1]一致的框架延遲。幀延遲不一致或渲染幀延遲不得在一秒鐘內發生5幀,且在一秒鐘內應低於1幀。
  • [ 8.2 /t-0-1]必須確保至少5MB /s的順序寫入效能。
  • [ 8.2 /t-0-2]必須確保隨機寫入至少為0.5Mb /s。
  • [ 8.2 /t-0-3]必須確保至少15mb /s的順序讀取效能。
  • [ 8.2 /t-0-4]必須確保至少3.5mb /s的隨機讀取效能。

如果電視設備實現包括改善AOSP中包含或擴展AOSP中包含的功能的設備電源管理的功能,則它們:

  • [ 8.3 /t-1-1]必須提供使用者負擔能力,以啟用和停用電池節省功能。

如果電視設備實現沒有電池:

如果電視設備實現具有電池,則可以:

  • [ 8.3 /t-1-3]必須提供使用者負擔,以顯示所有豁免應用程式備用和省力動力模式的應用程式。

電視設備實現:

  • [ 8.4 /t-0-1]必須提供每個組件功率配置文件,該輪廓定義每個硬體組件的當前消耗值以及由組件隨著時間的推移所記錄的Android開源專案站點所記錄的近似電池耗盡。
  • [ 8.4 /t-0-2]必須以毫安培小時(MAH)報告所有功耗值。
  • [ 8.4 /T-0-3]必須根據每個製程的UID報告CPU功耗。 Android開源專案透過uid_cputime核心模組實現滿足了需求。
  • [ 8.4 /t]如果無法將硬體組件用法歸因於應用程序,則應歸因於硬體組件本身。
  • [ 8.4 /t-0-4]必須透過adb shell dumpsys batterystats shell命令將此電源提供給應用程式開發人員。

2.3.5。安全模型

電視設備實現:

  • [ 9.11 /t-0-1]必須使用孤立的執行環境來備份金鑰庫實作。
  • [ 9.11 /t-0-2]必須具有RSA,AES,ECDA和HMAC加密演算法以及MD5,SHA1和SHA-2家族雜湊功能的實現,以正確地支援Android Keystore系統在該區域中支援的演算法,該演算法是安全隔離的。從核心上及以上運行的程式碼。安全隔離必須阻止核心或使用者空間程式碼可能存取包括DMA在內的隔離環境的內部狀態的所有潛在機制。上游Android開源專案(AOSP)透過使用可信賴的實作來滿足此要求,但是另一個基於ARM Trustzone的解決方案或第三方審查了基於適當的基於機管y的隔離的第三方審查的安全實作是替代選項。
  • [ 9.11 /T-0-3]必須在隔離的執行環境中執行鎖定螢幕身份驗證,並且只有在成功時,才能使用身份驗證的鍵。鎖定螢幕憑證必須以僅允許隔離的執行環境執行鎖定螢幕驗證的方式儲存。上游Android開源專案提供了Gatekeeper硬體抽象層(HAL)和Trusty,可用來滿足此要求。
  • [ 9.11 /t-0-4]必須支援金鑰證明,其中證明簽章金鑰受安全硬體保護,並在安全硬體中執行簽章。必須在足夠數量的裝置上共用證明簽章金鑰,以防止鍵用作裝置識別碼。滿足此要求的一種方法是共用相同的證明金鑰,除非產生至少100,000個給定的SKU單位。如果生產了超過100,000台SKU,則每100,000個單元可能會使用不同的鍵。

請注意,如果已經在較早的Android版本上啟動了設備實現,則該設備免除了以隔離的執行環境支援密鑰庫並支援密鑰證明的要求,除非它聲明android.hardware.fingerprint功能,而該功能該功能哪些功能需要一個由孤立的執行環境支援的金鑰庫。

如果電視設備實現支援安全的鎖定螢幕,則它們:

  • [ 9.11 /t-1-1]必須允許使用者選擇從解鎖到鎖定狀態的過渡的睡眠逾時,最小允許的超時時間為15秒或以下。

如果電視設備實現包括多個用戶,並且不聲明android.hardware.telephony功能標誌,則它們:

  • [ 9.5 /T-2-1]必須支援限製設定文件,該功能使設備所有者可以在設備上管理其他使用者及其功能。借助限制的配置文件,設備所有者可以快速設置單獨的環境供其他用戶工作,並且能夠管理在這些環境中可用的應用程式中進行細粒度限制的能力。

如果電視設備實作包含多個使用者並聲明android.hardware.telephony功能標誌,則它們:

  • [ 9.5 /t-3-1]不得支援受限的設定文件,而必須與AOSP實施控制項保持一致,以啟用 /停用其他使用者存取語音呼叫和SMS。

2.3.6。開發人員工具和選項相容性

電視設備實現:

  • 完美
    • [ 6.1 /t-0-1]必須將A /system/bin/perfetto二進位曝光到符合Perfetto文件的外殼使用者。
    • [ 6.1 /t-0-2] perfetto二進位必須接受作為符合Perfetto文件中定義的模式的Protobuf配置。
    • [ 6.1 /t-0-3] perfetto二進位必須作為輸出寫入符合Perfetto文檔中定義的模式的Protobuf追蹤。
    • [ 6.1 /t-0-4]必須透過perfetto二進位提供至少在Perfetto文件中描述的資料來源。

2.4.觀看要求

Android Watch設備是指設計用於戴在體內的Android設備,也許是在手腕上。

如果Android設備實現符合以下所有標準,則將其歸類為手錶:

  • 具有物理對角線長度在1.1到2.5英吋的螢幕。
  • 設有提供的機制,要戴在體內。

本節其餘部分的其他要求是特定於Android Watch設備實現的。

2.4.1.硬體

觀察設備實現:

  • [ 7.1 .1.1/w-0-1]必須具有一個物理對角線大小在1.1到2.5英吋的螢幕。

  • [ 7.2 .3/w-0-1]必須具備使用者可用的家庭功能,除了在UI_MODE_TYPE_WATCH中,還必須具有後背功能。

  • [ 7.2 .4/w-0-1]必須支援觸控螢幕輸入。

  • 強烈建議使用[ ​​7.3 .1/w-SR]包括3軸加速度計。

如果手錶設備實作包括GPS/GNSS接收器,並透過android.hardware.location.gps功能標誌向應用程式報告功能,則它們:

  • [ 7.3 .3/w-1-1]即使尚未報告從GPS/GNSS計算出的位置,也必須立即報告GNSS測量。
  • [ 7.3 .3/w-1-2]必須報告GNSS偽內和偽率率,在確定位置後,在開放的條件下,靜止或以少於0.2米/秒的加速度移動,足以計算計算位置在20公尺之內,至少95%的時間在0.2公尺/秒內的速度。

如果手錶設備實現包括3軸陀螺儀,則它們:

  • [ 7.3 .4/w-2-1]必須能夠測量每秒高達1000度的方向變化。

觀察設備實現:

  • [ 7.4 .3/w-0-1]必須支援藍牙。

  • [ 7.6 .1/w-0-1]必須至少有1 GB的非揮發性儲存空間可用於應用程式私人資料(又稱「/資料」分區)。

  • [ 7.6 .1/w-0-2]必須至少有416 MB的記憶體可用於核心和使用者空間。

  • [ 7.8 .1/w-0-1]必須包含麥克風。

  • [ 7.8 .2/w]可能但不應有音訊輸出。

2.4.2.多媒體

沒有其他要求。

2.4.3.軟體

觀察設備實現:

  • [ 3 /W-0-1]必須聲明功能android.hardware.type.watch
  • [ 3 /w-0-2]必須支援uimode = ui_mode_type_watch

觀察設備實現:

觀察聲明android.hardware.audio.output功能標誌的裝置實作:

2.4.4.性能和力量

如果手錶設備實現包括改善AOSP中包含或擴展AOSP中包含的功能的設備電源管理的功能,則它們:

  • 強烈建議[ 8.3 /w-sr]提供使用者負擔能力,以顯示所有豁免應用程式備用和省力動力模式的應用程式。
  • 強烈建議[ 8.3 /w-sr]提供使用者負擔能力,以啟用和停用電池節省功能。

觀察設備實現:

  • [ 8.4 /w-0-1]必須提供每個組件功率配置文件,該輪廓定義每個硬體組件的當前消耗值以及由組件隨時間推移引起的近似電池流量,如Android開源專案站點所記錄的那樣。
  • [ 8.4 /w-0-2]必須以毫安培小時(MAH)報告所有功耗值。
  • [ 8.4 /W-0-3]必須根據每個製程的UID報告CPU功耗。 Android開源專案透過uid_cputime核心模組實現滿足了需求。
  • [ 8.4 /w-0-4]必須透過adb shell dumpsys batterystats shell命令將此電源供應器提供給應用程式開發人員。
  • [ 8.4 /w]如果無法將硬體組件用法歸因於應用程序,則應歸因於硬體組件本身。

2.4.5。安全模型

如果手錶設備實現包括多個用戶,並且不聲明android.hardware.telephony功能標誌,則它們:

  • [ 9.5 /w-1-1]必須支援限製設定文件,該功能允許設備所有者在設備上管理其他使用者及其功能。借助限制的配置文件,設備所有者可以快速設置單獨的環境供其他用戶工作,並且能夠管理在這些環境中可用的應用程式中進行細粒度限制的能力。

如果手錶裝置實作包含多個使用者並聲明android.hardware.telephony功能標誌,則他們:

  • [ 9.5 /w-2-1]不得支援受限的設定文件,而必須與AOSP實作控制項的實作保持一致,以啟用 /停用其他使用者存取語音通話和SMS。

2.5.汽車要求

Android Automotive 實作是指運行 Android 作為部分或全部系統和/或資訊娛樂功能的作業系統的車輛主機。

如果Android設備的實作將其歸類為汽車,如果他們聲明功能android.hardware.type.automotive或滿足以下所有條件。

  • 作為汽車車輛的一部分或可插入汽車的一部分。
  • 正在使用駕駛座行中的螢幕作為主要顯示。

本節其餘部分的其他要求是特定於Android汽車設備實現的。

2.5.1.硬體

汽車設備實現:

如果汽車設備實現包括3軸加速度計,則它們:

如果汽車設備實現包括3軸陀螺儀,則它們:

  • [ 7.3 .4/A-2-1]必須能夠報告至少100 Hz的頻率。
  • [ 7.3 .4/A-2-2]也必須實作TYPE_GYROSCOPE_UNCALIBRATED感測器。
  • [ 7.3 .4/a-2-3]必須能夠測量每秒250度的方向變化。
  • 強烈建議使用[ ​​7.3 .4/a-sr]將陀螺儀的測量範圍配置為+/- 250dps,以最大程度地提高分辨率

汽車設備實現:

  • [ 7.4 .3/a-0-1]必須支援藍牙,並應支援藍牙LE。
  • [ 7.4 .3/a-0-2] Android汽車實作必須支援以下藍牙設定檔:

    • 透過免持個人資料(HFP)打電話。
    • 透過音訊分發設定檔 (A2DP) 進行媒體播放。
    • 透過遠端控製設定檔 (AVRCP) 進行媒體播放控制。
    • 使用電話簿存取設定檔(PBAP)聯繫共用。
  • 強烈建議[ 7.4 .3/a-SR]支援訊息存取設定檔(MAP)。

  • [ 7.4 .5/a]應包括基於蜂窩網路的數據連接的支援。

  • [ 7.4 .5/a]可以使用系統API NetworkCapabilities#NET_CAPABILITY_OEM_PAID常數用於系統應用程式可用的網路。

外觀攝影機是一台攝像頭,像儀表板一樣在設備實現之外映像場景。

汽車設備實現:

  • 應包括一個或多個外部視圖攝影機。

如果汽車設備的實現包括外部視圖攝像頭,則對於這樣的相機,它們:

  • [ 7.5 /a-1-1]除非符合相機核心要求,否則不得透過Android相機API存取外部視圖攝影機。
  • [ 7.5 /a-SR]強烈建議不要旋轉或水平鏡像相機預覽。
  • 強烈建議將[ 7.5 .5/a-SR]定向,以使攝影機的長尺寸與地平線對齊。
  • 強烈建議[ 7.5 /A-SR]具有至少1.3兆像素的分辨率。
  • 應具有固定的對焦或EDOF(範圍擴展深度)硬體。
  • 可能具有相機驅動程式中實現的硬體自動對焦或軟體自動對焦。

汽車設備實現:

  • [ 7.6 .1/a-0-1]必須至少有4 GB的非揮發性儲存空間可用於應用程式私人資料(又稱「/資料」分割區)。

  • [ 7.6 .1/a]應格式化資料分割區,以提供改進的快閃記憶體儲存的效能和壽命,例如使用f2fs檔案系統。

如果汽車設備實現透過內部不可拆卸存儲提供共享的外部存儲,則它們:

  • 強烈建議[ 7.6 .1/a-sr]在外部記憶體上執行的操作,例如使用SDCardFS ,以減少I/O開銷。

如果汽車設備實現為32位:

  • [ 7.6 .1/a-1-1]如果使用以下密度,則核心和使用者空間可用的記憶體必須至少為512MB:

    • 在小/普通螢幕上280DPI或較低
    • LDPI或在超大螢幕上較低
    • 大螢幕上的MDPI或較低
  • [ 7.6 .1/a-1-2]如果使用以下任何密度,則核心和使用者空間的記憶體必須至少為608MB:

    • XHDPI或更高的小/正常螢幕
    • 大螢幕上的HDPI或更高
    • MDPI或更高的大螢幕
  • [ 7.6 .1/a-1-3]如果使用以下任何密度,則核心和使用者空間的記憶體必須至少為896MB:

    • 小/普通螢幕上的400DPI或更高
    • xhdpi或更高的大螢幕
    • TVDPI或更高的大螢幕
  • [ 7.6 .1/a-1-4]如果使用以下任何密度,則可用於核心和使用者空間的記憶體必須至少為1344MB:

    • 小/普通螢幕上的560DPI或更高
    • 大螢幕上的400DPI或更高
    • xhdpi或更高的大螢幕

如果汽車設備實現為64位:

  • [ 7.6 .1/a-2-1]如果使用以下密度,則核心和使用者空間可用的記憶體必須至少為816MB:

    • 在小/普通螢幕上280DPI或較低
    • LDPI或在超大螢幕上較低
    • 大螢幕上的MDPI或較低
  • [ 7.6 .1/a-2-2]如果使用以下密度,則核心和使用者空間可用的記憶體必須至少為944MB:

    • XHDPI或更高的小/正常螢幕
    • 大螢幕上的HDPI或更高
    • MDPI或更高的大螢幕
  • [ 7.6 .1/a-2-3]如果使用以下任何密度,則可以使用核心和使用者空間的記憶體至少為1280MB:

    • 小/普通螢幕上的400DPI或更高
    • xhdpi或更高的大螢幕
    • TVDPI或更高的大螢幕
  • [ 7.6 .1/a-2-4]如果使用以下任何密度,則核心和使用者空間的記憶體必須至少為1824MB:

    • 小/普通螢幕上的560DPI或更高
    • 大螢幕上的400DPI或更高
    • xhdpi或更高的大螢幕

請注意,上面的「可用的記憶體和用戶空間的記憶體」是指除了已經專用於硬體元件(例如無線電,視訊等)的任何記憶體之外提供的記憶體空間,而這些記憶體不在核心對裝置實現的控制下。

汽車設備實現:

  • [ 7.7 .1/a]應包括支援外圍模式的USB連接埠。

汽車設備實現:

  • [ 7.8 .1/A-0-1]必須包括麥克風。

汽車設備實現:

  • [ 7.8 .2/a-0-1]必須具有音訊輸出並聲明android.hardware.audio.output

2.5.2.多媒體

汽車設備實作必須支援以下音訊編碼和解碼格式,並使它們可用於第三方應用程式:

  • [ 5.1 /a-0-1] MPEG-4 AAC設定檔(AAC LC)
  • [ 5.1 /a-0-2] MPEG-4 HE AAC概況(AAC+)
  • [ 5.1 /A-0-3] AAC ELD(增強的低延遲AAC)

汽車設備實作必須支援以下視訊編碼格式,並使它們可用於第三方應用程式:

  • [ 5.2 /a-0-1] H.264 AVC
  • [ 5.2 /a-0-2] VP8

汽車設備實作必須支援以下視訊解碼格式,並使它們可用於第三方應用程式:

  • [ 5.3 /a-0-1] H.264 AVC
  • [ 5.3 /A-0-2] MPEG-4 SP
  • [ 5.3 /a-0-3] VP8
  • [ 5.3 /a-0-4] VP9

強烈建議使用汽車設備實作來支援以下視訊解碼:

  • [ 5.3 /A-SR] H.265 HEVC

2.5.3.軟體

汽車設備實現:

  • [ 3 /A-0-1]必須宣告功能android.hardware.type.automotive

  • [ 3 /a-0-2]必須支援uimode = UI_MODE_TYPE_CAR

  • [ 3 /a-0-3] 必須支援android.car.*名稱空間。

  • [ 3.2 .1/A-0-1]必須支援並執行所有由汽車許可參考頁所記錄的權限常數。

  • [ 3.4 .1/a-0-1]必須提供android.webkit.Webview API的完整實作。

  • [ 3.8 .3/a-0-1]必須顯示使用通知的通知。當第三方應用程式要求時, Notification.CarExtender API。

  • 強烈建議[ 3.8 .4/a-SR]在設備上實施助手來處理輔助操作

如果汽車設備的實現包括一個按鈕按鈕,則它們:

  • [ 3.8 .4/a-1-1]必須使用推動對話按鈕作為指定互動的簡短按下來啟動使用者選擇的輔助應用程序,換句話說,實現VoiceInteractionService的應用程式。

汽車設備實現:

汽車設備實現:

如果汽車設備實作包括預設啟動器應用,則它們:

汽車設備實現:

2.5.4.性能和力量

汽車設備實現:

  • [ 8.2 /a-0-1]必須根據每個進程的UID報告讀取和寫入非揮發性儲存的位元組數量,以便透過System Api android.car.storagemonitoring.CarStorageMonitoringManager向開發人員使用統計資料。 Android開源專案透過uid_sys_stats核心模組符合要求。
  • [ 8.3 /a-1-3]必須至少進入車庫模式,然後才能關閉汽車。
  • [ 8.3 /A-1-4]必須處於車庫模式至少15分鐘,除非:
    • 電池排出了。
    • 沒有安排空閒工作。
    • 駕駛員退出車庫模式。
  • [ 8.4 /A-0-1]必須提供每個組件功率配置文件,該輪廓定義每個硬體組件的當前消耗值以及由組件隨時間推移所致的電池耗盡,如Android開源專案網站所記錄的那樣。
  • [ 8.4 /A-0-2]必須以毫安培小時(MAH)報告所有功耗值。
  • [ 8.4 /A-0-3]必須根據每個製程的UID報告CPU功耗。 Android開源專案透過uid_cputime核心模組實現滿足了需求。
  • [ 8.4 /a]如果無法將硬體組件用法歸因於應用程序,則應歸因於硬體組件本身。
  • [ 8.4 /a-0-4]必須透過adb shell dumpsys batterystats shell命令將此電源提供給應用程式開發人員。

2.5.5。安全模型

如果汽車設備實現支援多個用戶,則他們:

汽車設備實現:

  • [ 9.11 /A-0-1]必須在隔離執行環境中備份金鑰庫實作。
  • [ 9.11 /A-0-2]必須具有RSA,AES,ECDA和HMAC加密演算法以及MD5,SHA1和SHA-2家族雜湊功能的實現,以正確地支援Android Keystore系統在該區域中支援的演算法,該演算法是安全隔離的。從核心上及以上運行的程式碼。安全隔離必須阻止核心或使用者空間程式碼可能存取包括DMA在內的隔離環境的內部狀態的所有潛在機制。上游Android開源專案(AOSP)透過使用可信賴的實作來滿足此要求,但是另一個基於ARM Trustzone的解決方案或第三方審查了基於適當的基於機管y的隔離的第三方審查的安全實作是替代選項。
  • [ 9.11 /a-0-3]必須在隔離的執行環境中執行鎖定螢幕身份驗證,並且只有在成功時,才能使用身份驗證的鍵。鎖定螢幕憑證必須以僅允許隔離的執行環境執行鎖定螢幕驗證的方式儲存。上游Android開源專案提供了Gatekeeper硬體抽象層(HAL)和Trusty,可用來滿足此要求。
  • [ 9.11 /a-0-4]必須支援金鑰證明,其中證明簽章金鑰受安全硬體保護,並在安全硬體中執行簽章。必須在足夠數量的裝置上共用證明簽章金鑰,以防止鍵用作裝置識別碼。滿足此要求的一種方法是共用相同的證明金鑰,除非產生至少100,000個給定的SKU單位。如果生產了超過100,000台SKU,則每100,000個單元可能會使用不同的鍵。

請注意,如果已經在較早的Android版本上啟動了設備實現,則該設備免除了以隔離的執行環境支援密鑰庫並支援密鑰證明的要求,除非它聲明android.hardware.fingerprint功能,而該功能該功能哪些功能需要一個由孤立的執行環境支援的金鑰庫。

如果汽車設備實現支援安全的鎖定螢幕,則它們:

  • [ 9.11 /a-1-1]必須允許使用者選擇從解鎖到鎖定狀態的過渡的睡眠超時,最小允許的超時時間為15秒或更短。

汽車設備實現:

  • [ 9.14 /a-0-1]必須來自Android Framework車輛子系統(例如,允許清單允許的訊息類型和訊息來源)的網務訊息。
  • [ 9.14 /a-0-2]必須監視拒絕來自Android框架或第三方應用程式的服務攻擊。這種防禦惡意軟體會淹沒車輛網路的流量,這可能會導致車輛子系統故障。

2.5.6。開發人員工具和選項相容性

汽車設備實現:

2.6。 Tablet Requirements

An Android Tablet device refers to an Android device implementation that meets all the following criteria:

  • Typically used by holding in both hands.
  • Does not have a clamshell or convertible configuration.
  • Any physical keyboard implementation used with the device MUST connect by means of a standard connection.
  • Has a power source that provides mobility, such as a battery.
  • Has a physical diagonal screen size in the range of 7 to 18 inches.

Tablet device implementations have similar requirements to handheld device implementations. The exceptions are indicated by an * in that section and noted for reference in this section.

2.6.1.硬體

螢幕尺寸

  • [ 7.1 .1.1/Tab-0-1] MUST have a screen in the range of 7 to 18 inches.

陀螺儀

If Tablet device implementations include a 3-axis gyroscope, they:

  • [ 7.3 .4/Tab-1-1] MUST be capable of measuring orientation changes up to 1000 degrees per second.

Minimum Memory and Storage (Section 7.6.1)

The screen densities listed for small/normal screens in the handheld requirements are not applicable to tablets.

USB peripheral mode (Section 7.7.1)

If tablet device implementations include a USB port supporting peripheral mode, they:

  • [ 7.7.1 /Tab] MAY implement the Android Open Accessory (AOA) API.

Virtual Reality Mode (Section 7.9.1)

Virtual Reality High Performance (Section 7.9.2)

Virtual reality requirements are not applicable to tablets.

2.6.2. Security Model

Keys and Credentials (Section 9.11)

Refer to Section [ 9.11 ].

If Tablet device implementations include multiple users and do not declare the android.hardware.telephony feature flag, they:

  • [ 9.5 /T-1-1] MUST support restricted profiles, a feature that allows device owners to manage additional users and their capabilities on the device. With restricted profiles, device owners can quickly set up separate environments for additional users to work in, with the ability to manage finer-grained restrictions in the apps that are available in those environments.

If Tablet device implementations include multiple users and declare the android.hardware.telephony feature flag, they:

  • [ 9.5 /T-2-1] MUST NOT support restricted profiles but MUST align with the AOSP implementation of controls to enable /disable other users from accessing the voice calls and SMS.

3、軟體

3.1.託管 API 相容性

託管的 Dalvik 字節碼執行環境是 Android 應用程式的主要工具。 Android 應用程式介面 (API) 是向在託管執行時間環境中運行的應用程式公開的一組 Android 平台介面。

設備實現:

  • [C-0-1] MUST provide complete implementations, including all documented behaviors, of any documented API exposed by the Android SDK or any API decorated with the “@SystemApi” marker in the upstream Android source code.

  • [C-0-2] MUST support/preserve all classes, methods, and associated elements marked by the TestApi annotation (@TestApi).

  • [C-0-3] MUST NOT omit any managed APIs, alter API interfaces or signatures, deviate from the documented behavior, or include no-ops, except where specifically allowed by this Compatibility Definition.

  • [C-0-4] MUST still keep the APIs present and behave in a reasonable way, even when some hardware features for which Android includes APIs are omitted.有關此場景的具體要求,請參閱第 7 節

  • [C-0-5] MUST NOT allow third-party apps to use non-SDK interfaces, which are defined as methods and fields in the Java language packages that are in the boot classpath in AOSP, and that do not form part of the public SDK. This includes APIs decorated with the @hide annotation but not with a @SystemAPI , as described in the SDK documents and private and package-private class members.

  • [C-0-6] MUST ship with each and every non-SDK interface on the same restricted lists as provided via the provisional list and denylist flags in prebuilts/runtime/appcompat/hiddenapi-flags.csv path for the appropriate API level branch in the AOSP.

    However they:

    • MAY, if a hidden API is absent or implemented differently on the device implementation, move the hidden API into the denylist or omit it from all restricted lists.
    • MAY, if a hidden API does not already exist in the AOSP, add the hidden API to any of the restricted lists.
  • [C-0-7] MUST support the signed config dynamic update mechanism to remove non-SDK interfaces from a restricted list by embedding signed configuration in any APK, using the existing public keys present in AOSP.

3.1.1.安卓擴充

Android 支援擴充託管 API,同時保持相同的 API 等級版本。

  • [C-0-1] Android device implementations MUST preload the AOSP implementation of both the shared library ExtShared and services ExtServices with versions higher than or equal to the minimum versions allowed per each API level.例如,執行 API 等級 24 的 Android 7.0 裝置實作必須至少包含版本 1。

3.1.2. Android Library

Due to Apache HTTP client deprecation , device implementations:

  • [C-0-1] MUST NOT place the org.apache.http.legacy library in the bootclasspath.
  • [C-0-2] MUST add the org.apache.http.legacy library to the application classpath only when the app satisfies one of the following conditions:
    • Targets API level 28 or lower.
    • Declares in its manifest that it needs the library by setting the android:name attribute of <uses-library> to org.apache.http.legacy .

The AOSP implementation meets these requirements.

3.2.軟 API 相容性

除了第 3.1 節中的託管 API 之外,Android 還包括一個重要的僅運行時「軟」API,其形式為意圖、權限和 Android 應用程式的類似方面,這些方面無法在應用程式編譯時強制執行。

3.2.1.權限

  • [C-0-1] Device implementers MUST support and enforce all permission constants as documented by the Permission reference page .請注意,第 9 節列出了與 Android 安全模型相關的其他要求。

3.2.2.建構參數

Android API 在android.os.Build 類別中包含許多常數,用於描述目前裝置。

  • [C-0-1] To provide consistent, meaningful values across device implementations, the table below includes additional restrictions on the formats of these values to which device implementations MUST conform.
範圍細節
版本.發布目前執行的 Android 系統的版本,採用人類可讀的格式。 This field MUST have one of the string values defined in 10 .
版本.SDK目前執行的 Android 系統的版本,採用第三方應用程式程式碼可存取的格式。 For Android 10, this field MUST have the integer value 10_INT.
版本.SDK_INT目前執行的 Android 系統的版本,採用第三方應用程式程式碼可存取的格式。 For Android 10, this field MUST have the integer value 10_INT.
版本.增量裝置實現者選擇的值,以人類可讀的格式指定目前正在執行的 Android 系統的特定版本。該值不得重複用於提供給最終用戶的不同建置。此欄位的典型用途是指示使用哪個版本號或原始碼控制變更標識符來產生版本。 The value of this field MUST be encodable as printable 7-bit ASCII and match the regular expression “^[^ :\/~]+$”.
木板設備實現者選擇的值,以人類可讀的格式標識設備使用的特定內部硬體。此欄位的一個可能用途是指示為設備供電的板的特定版本。此欄位的值必須可編碼為 7 位元 ASCII 並符合正規表示式「^[a-zA-Z0-9_-]+$」。
品牌反映最終用戶所知的與設備相關的品牌名稱的值。必須採用人類可讀的格式,並且應該代表設備的製造商或設備銷售的公司品牌。此欄位的值必須可編碼為 7 位元 ASCII 並符合正規表示式「^[a-zA-Z0-9_-]+$」。
支援_ABIS本機程式碼的指令集名稱(CPU 類型 + ABI 約定)。請參閱第 3.3 節。本機 API 相容性
SUPPORTED_32_BIT_ABIS本機程式碼的指令集名稱(CPU 類型 + ABI 約定)。請參閱第 3.3 節。本機 API 相容性
SUPPORTED_64_BIT_ABIS本機程式碼的第二指令集(CPU 類型 + ABI 約定)的名稱。請參閱第 3.3 節。本機 API 相容性
CPU_ABI本機程式碼的指令集名稱(CPU 類型 + ABI 約定)。請參閱第 3.3 節。本機 API 相容性
CPU_ABI2本機程式碼的第二指令集(CPU 類型 + ABI 約定)的名稱。請參閱第 3.3 節。本機 API 相容性
裝置設備實現者選擇的值,包含標識硬體功能配置和設備工業設計的開發名稱或代號。此欄位的值必須可編碼為 7 位元 ASCII 並符合正規表示式「^[a-zA-Z0-9_-]+$」。該設備名稱在產品的生命週期內不得更改。
指紋唯一標識此建置的字串。它應該是合理的人類可讀的。它必須遵循以下模板:

$(品牌)/$(產品)/
$(設備):$(版本.發佈)/$(ID)/$(版本.增量):$(類型)/$(標籤)

例如:

acme/我的產品/
mydevice:10/LMYXX/3359:userdebug/test-keys

指紋不得包含空白字元。此欄位的值必須可編碼為 7 位元 ASCII。

硬體硬體的名稱(來自核心命令列或/proc)。它應該是合理的人類可讀的。此欄位的值必須可編碼為 7 位元 ASCII 並符合正規表示式「^[a-zA-Z0-9_-]+$」。
主持人一個字串,以人類可讀的格式唯一標識建構建構的主機。該欄位的具體格式沒有要求,但不能為 null 或空字串 ("")。
ID設備實現者選擇的標識符,用於引用特定版本,採用人類可讀的格式。該欄位可以與 android.os.Build.VERSION.INCRMENTAL 相同,但應該是一個對於最終用戶區分軟體版本足夠有意義的值。此欄位的值必須可編碼為 7 位元 ASCII 並符合正規表示式「^[a-zA-Z0-9._-]+$」。
製造商產品原始設備製造商 (OEM) 的商品名稱。該欄位的具體格式沒有要求,但不能為 null 或空字串 ("")。 This field MUST NOT change during the lifetime of the product.
模型設備實現者選擇的值,包含最終使用者已知的設備名稱。此名稱應與設備行銷和銷售給最終用戶時使用的名稱相同。該欄位的具體格式沒有要求,但不能為 null 或空字串 ("")。 This field MUST NOT change during the lifetime of the product.
產品設備實施者選擇的值,包含特定產品 (SKU) 的開發名稱或程式碼名稱,該產品在同一品牌中必須是唯一的。必須是人類可讀的,但不一定供最終用戶查看。此欄位的值必須可編碼為 7 位元 ASCII 並符合正規表示式「^[a-zA-Z0-9_-]+$」。該產品名稱在產品的生命週期內不得更改。
串口MUST return "UNKNOWN".
標籤由設備實現者選擇的以逗號分隔的標籤列表,可進一步區分建置。 The tags MUST be encodable as 7-bit ASCII and match the regular expression “^[a-zA-Z0-9._-]+” and MUST have one of the values corresponding to the three typical Android platform signing configurations: release-keys, dev-keys, and test-keys.
時間表示建構發生時間的時間戳記的值。
類型由設備實現者選擇的值,指定建置的運行時配置。此欄位必須具有與三種典型 Android 運行時配置相對應的值之一:user、userdebug 或 eng。
使用者產生建置的使用者(或自動使用者)的名稱或使用者 ID。該欄位的具體格式沒有要求,但不能為 null 或空字串 ("")。
安全補丁指示建置的安全性修補程式等級的值。它必須表明該構建不會以任何方式受到指定 Android 公共安全公告中描述的任何問題的影響。它必須採用 [YYYY-MM-DD] 格式,與Android 公共安全公告Android 安全通報中記錄的定義字串相符,例如「2015-11-01」。
基本作業系統表示建置的 FINGERPRINT 參數的值,除 Android 公共安全公告中提供的補丁外,該值與此建置相同。它必須報告正確的值,如果這樣的建置不存在,則報告空字串(“”)。
BOOTLOADER A value chosen by the device implementer identifying the specific internal bootloader version used in the device, in human-readable format.此欄位的值必須可編碼為 7 位元 ASCII 並符合正規表示式「^[a-zA-Z0-9._-]+$」。
getRadioVersion() MUST (be or return) a value chosen by the device implementer identifying the specific internal radio/modem version used in the device, in human-readable format. If a device does not have any internal radio/modem it MUST return NULL. The value of this field MUST be encodable as 7-bit ASCII and match the regular expression “^[a-zA-Z0-9._-,]+$”.
getSerial() MUST (be or return) a hardware serial number, which MUST be available and unique across devices with the same MODEL and MANUFACTURER. The value of this field MUST be encodable as 7-bit ASCII and match the regular expression “^[a-zA-Z0-9._-,]+$”.

3.2.3.意圖相容性

3.2.3.1.核心應用意圖

Android 意圖允許應用程式元件向其他 Android 元件請求功能。 Android 上游項目包括被視為核心 Android 應用程式的應用程式列表,這些應用程式實現了多種意圖模式來執行常見操作。

  • [C-0-1] Device implementations MUST preload one or more applications or service components with an intent handler, for all the public intent filter patterns defined by the following core android applications in AOSP:

    • 英式鐘
    • 瀏覽器
    • 日曆
    • 聯絡方式
    • 畫廊
    • 全球搜尋
    • 啟動器
    • 音樂
    • 設定
3.2.3.2.意圖解析
  • [C-0-1] As Android is an extensible platform, device implementations MUST allow each intent pattern referenced in section 3.2.3.1 , except for Settings, to be overridden by third-party applications. The upstream Android open source implementation allows this by default.

  • [C-0-2] Device implementers MUST NOT attach special privileges to system applications' use of these intent patterns, or prevent third-party applications from binding to and assuming control of these patterns.該禁止具體包括但不限於停用「選擇器」使用者介面,該介面允許使用者在全部處理相同意圖模式的多個應用程式之間進行選擇。

  • [C-0-3] Device implementations MUST provide a user interface for users to modify the default activity for intents.

  • 但是,當預設活動為資料 URI 提供更具體的屬性時,裝置實作可以為特定 URI 模式(例如 http://play.google.com)提供預設活動。例如,指定資料 URI「http://www.android.com」的意圖過濾器模式比瀏覽器的「http://」核心意圖模式更具體。

Android 還包含一種機制,供第三方應用程式為某些類型的 Web URI 意圖聲明權威的預設應用程式連結行為。當在應用程式的意圖過濾器模式中定義此類權威聲明時,設備實作:

  • [C-0-4] MUST attempt to validate any intent filters by performing the validation steps defined in the Digital Asset Links specification as implemented by the Package Manager in the upstream Android Open Source Project.
  • [C-0-5] MUST attempt validation of the intent filters during the installation of the application and set all successfully validated URI intent filters as default app handlers for their URIs.
  • 如果成功驗證但其他候選 URI 過濾器驗證失敗,則可以將特定 URI 意圖過濾器設定為其 URI 的預設應用程式處理程序。如果裝置實作這樣做,它必須在設定選單中為使用者提供適當的每 URI 模式覆蓋。
  • 必須在設定中為使用者提供每個應用程式的應用程式連結控件,如下所示:
    • [C-0-6] The user MUST be able to override holistically the default app links behavior for an app to be: always open, always ask, or never open, which MUST apply to all candidate URI intent filters equally.
    • [C-0-7] The user MUST be able to see a list of the candidate URI intent filters.
    • 設備實作可以為使用者提供基於每個意圖過濾器覆蓋已成功驗證的特定候選 URI 意圖過濾器的能力。
    • [C-0-8] The device implementation MUST provide users with the ability to view and override specific candidate URI intent filters if the device implementation lets some candidate URI intent filters succeed verification while some others can fail.
3.2.3.3.意圖命名空間
  • [C-0-1] Device implementations MUST NOT include any Android component that honors any new intent or broadcast intent patterns using an ACTION, CATEGORY, or other key string in the android.或com.android。命名空間。
  • [C-0-2] Device implementers MUST NOT include any Android components that honor any new intent or broadcast intent patterns using an ACTION, CATEGORY, or other key string in a package space belonging to another organization.
  • [C-0-3] Device implementers MUST NOT alter or extend any of the intent patterns used by the core apps listed in section 3.2.3.1 .
  • 設備實作可以包括使用與其自己的組織明確相關的命名空間的意圖模式。該禁止類似於3.6 節中針對 Java 語言類別指定的禁止。
3.2.3.4.廣播意圖

第三方應用程式依靠平台廣播某些意圖,以通知它們硬體或軟體環境的變化。

設備實現:

  • [C-0-1] MUST broadcast the public broadcast intents in response to appropriate system events as described in the SDK documentation. Note that this requirement is not conflicting with section 3.5 as the limitation for background applications are also described in the SDK documentation.
3.2.3.5.預設應用程式設定

Android 包含的設定可讓用戶輕鬆選擇預設應用程序,例如主螢幕或簡訊。

在有意義的情況下,設備實作必須提供類似的設定選單,並與 SDK 文件中所述的意圖過濾器模式和 API 方法相容,如下所示。

If device implementations report android.software.home_screen , they:

If device implementations report android.hardware.telephony , they:

If device implementations report android.hardware.nfc.hce , they:

If device implementations support the VoiceInteractionService and have more than one application using this API installed at a time, they:

3.2.4. Activities on secondary/multiple displays

If device implementations allow launching normal Android Activities on more than one display, they:

  • [C-1-1] MUST set the android.software.activities_on_secondary_displays feature flag.
  • [C-1-2] MUST guarantee API compatibility similar to an activity running on the primary display.
  • [C-1-3] MUST land the new activity on the same display as the activity that launched it, when the new activity is launched without specifying a target display via the ActivityOptions.setLaunchDisplayId() API.
  • [C-1-4] MUST destroy all activities, when a display with the Display.FLAG_PRIVATE flag is removed.
  • [C-1-5] MUST securely hide content on all screens when the device is locked with a secure lock screen, unless the app opts in to show on top of lock screen using Activity#setShowWhenLocked() API.
  • SHOULD have android.content.res.Configuration which corresponds to that display in order to be displayed, operate correctly, and maintain compatibility if an activity is launched on secondary display.

If device implementations allow launching normal Android Activities on secondary displays and a secondary display has the android.view.Display.FLAG_PRIVATE flag:

  • [C-3-1] Only the owner of that display, system, and activities that are already on that display MUST be able to launch to it. Everyone can launch to a display that has android.view.Display.FLAG_PUBLIC flag.

3.3.本機 API 相容性

本機程式碼相容性具有挑戰性。 For this reason, device implementers are:

  • [SR] STRONGLY RECOMMENDED to use the implementations of the libraries listed below from the upstream Android Open Source Project.

3.3.1.應用程式二進位接口

託管 Dalvik 字節碼可以呼叫應用程式.apk檔案中提供的本機程式碼,作為針對適當設備硬體架構編譯的 ELF .so檔。由於本機程式碼高度依賴底層處理器技術,Android 在 Android NDK 中定義了許多應用程式二進位介面 (ABI)。

設備實現:

  • [C-0-1] MUST be compatible with one or more defined ABIs and implement compatibility with the Android NDK.
  • [C-0-2] MUST include support for code running in the managed environment to call into native code, using the standard Java Native Interface (JNI) semantics.
  • [C-0-3] MUST be source-compatible (ie header-compatible) and binary-compatible (for the ABI) with each required library in the list below.
  • [C-0-5] MUST accurately report the native Application Binary Interface (ABI) supported by the device, via the android.os.Build.SUPPORTED_ABIS , android.os.Build.SUPPORTED_32_BIT_ABIS , and android.os.Build.SUPPORTED_64_BIT_ABIS parameters, each a comma separated list of ABIs ordered from the most to the least preferred one.
  • [C-0-6] MUST report, via the above parameters, a subset of the following list of ABIs and MUST NOT report any ABI not on the list.

    • armeabi
    • armeabi-v7a
    • arm64-v8a
    • x86
    • x86-64
    • [C-0-7] MUST make all the following libraries, providing native APIs, available to apps that include native code:

    • libaaudio.so (AAudio native audio support)

    • libamidi.so (native MIDI support, if feature android.software.midi is claimed as described in Section 5.9)
    • libandroid.so(原生 Android 活動支援)
    • libc(C 庫)
    • libcamera2ndk.so
    • libdl(動態連結器)
    • libEGL.so(原生 OpenGL 表面管理)
    • libGLESv1_CM.so (OpenGL ES 1.x)
    • libGLESv2.so(OpenGL ES 2.0)
    • libGLESv3.so (OpenGL ES 3.x)
    • libicui18n.so
    • 庫克庫克
    • libjnigraphics.so
    • liblog(Android 日誌記錄)
    • libmediandk.so(原生媒體 API 支援)
    • libm(數學庫)
    • libneuralnetworks.so (Neural Networks API)
    • libOpenMAXAL.so(OpenMAX AL 1.0.1 支援)
    • libOpenSLES.so(OpenSL ES 1.0.1 音訊支援)
    • libRS.so
    • libstdc++(對 C++ 的最低支援)
    • libvulkan.so(Vulkan)
    • libz(Zlib 壓縮)
    • JNI介面
  • [C-0-8] MUST NOT add or remove the public functions for the native libraries listed above.

  • [C-0-9] MUST list additional non-AOSP libraries exposed directly to third-party apps in /vendor/etc/public.libraries.txt .
  • [C-0-10] MUST NOT expose any other native libraries, implemented and provided in AOSP as system libraries, to third-party apps targeting API level 24 or higher as they are reserved.
  • [C-0-11] MUST export all the OpenGL ES 3.1 and Android Extension Pack function symbols, as defined in the NDK, through the libGLESv3.so library. Note that while all the symbols MUST be present, section 7.1.4.1 describes in more detail the requirements for when the full implementation of each corresponding functions are expected.
  • [C-0-12] MUST export function symbols for the core Vulkan 1.0 function symbols, as well as the VK_KHR_surface , VK_KHR_android_surface , VK_KHR_swapchain , VK_KHR_maintenance1 , and VK_KHR_get_physical_device_properties2 extensions through the libvulkan.so library. Note that while all the symbols MUST be present, section 7.1.4.2 describes in more detail the requirements for when the full implementation of each corresponding functions are expected.
  • 應使用上游 Android 開源專案中提供的源代碼和頭文件進行構建

Note that future releases of Android may introduce support for additional ABIs.

3.3.2. 32 位元 ARM 本機程式碼相容性

If device implementations report the support of the armeabi ABI, they:

  • [C-3-1] MUST also support armeabi-v7a and report its support, as armeabi is only for backwards compatibility with older apps.

If device implementations report the support of the armeabi-v7a ABI, for apps using this ABI, they:

  • [C-2-1] MUST include the following lines in /proc/cpuinfo , and SHOULD NOT alter the values on the same device, even when they are read by other ABIs.

    • Features: , followed by a list of any optional ARMv7 CPU features supported by the device.
    • CPU architecture: , followed by an integer describing the device's highest supported ARM architecture (eg, "8" for ARMv8 devices).
  • [C-2-2] MUST always keep the following operations available, even in the case where the ABI is implemented on an ARMv8 architecture, either through native CPU support or through software emulation:

    • SWP and SWPB instructions.
    • SETEND instruction.
    • CP15ISB, CP15DSB, and CP15DMB barrier operations.
  • [C-2-3] MUST include support for the Advanced SIMD (aka NEON) extension.

3.4.網路相容性

3.4.1.網頁視圖相容性

If device implementations provide a complete implementation of the android.webkit.Webview API, they:

  • [C-1-1] MUST report android.software.webview .
  • [C-1-2] MUST use the Chromium Project build from the upstream Android Open Source Project on the Android 10 branch for the implementation of the android.webkit.WebView API.
  • [C-1-3] The user agent string reported by the WebView MUST be in this format:

    Mozilla/5.0 (Linux; Android $(VERSION); [$(MODEL)] [Build/$(BUILD)]; wv) AppleWebKit/537.36 (KHTML, like Gecko) Version/4.0 $(CHROMIUM_VER) Mobile Safari/537.36

    • $(VERSION) 字串的值必須與 android.os.Build.VERSION.RELEASE 的值相同。
    • The $(MODEL) string MAY be empty, but if it is not empty it MUST have the same value as android.os.Build.MODEL.
    • "Build/$(BUILD)" MAY be omitted, but if it is present the $(BUILD) string MUST be the same as the value for android.os.Build.ID.
    • $(CHROMIUM_VER) 字串的值必須是上游 Android 開源專案中 Chromium 的版本。
    • 設備實作可以在用戶代理字串中省略 Mobile。
  • WebView 元件應該包含對盡可能多的 HTML5 功能的支持,並且如果它支援該功能,則應該符合HTML5 規範

  • [C-1-4] MUST render the provided content or remote URL content in a process that is distinct from the application that instantiates the WebView. Specifically the separate renderer process MUST hold lower privilege, run as a separate user ID, have no access to the app's data directory, have no direct network access, and only have access to the minimum-required system services over Binder. The AOSP implementation of WebView meets this requirement.

Note that if device implementations are 32-bit or declare the feature flag android.hardware.ram.low , they are exempted from C-1-3.

3.4.2.瀏覽器相容性

If device implementations include a standalone Browser application for general web browsing, they:

  • [C-1-1] MUST support each of these APIs associated with HTML5:
  • [C-1-2] MUST support the HTML5/W3C webstorage API and SHOULD support the HTML5/W3C IndexedDB API .請注意,隨著 Web 開發標準機構逐漸轉向支援 IndexedDB 而不是 Webstorage,IndexedDB 預計將成為 Android 未來版本中的必要組件。
  • MAY ship a custom user agent string in the standalone Browser application.
  • SHOULD implement support for as much of HTML5 as possible on the standalone Browser application (whether based on the upstream WebKit Browser application or a third-party replacement).

However, If device implementations do not include a standalone Browser application, they:

  • [C-2-1] MUST still support the public intent patterns as described in section 3.2.3.1 .

3.5. API 行為相容性

設備實現:

  • [C-0-9] MUST ensure that API behavioral compatibility is applied for all installed apps unless they are restricted as described in Section 3.5.1 .
  • [C-0-10] MUST NOT implement the allowlisting approach that ensures API behavioral compatibility only for apps that are selected by device implementers.

The behaviors of each of the API types (managed, soft, native, and web) MUST be consistent with the preferred implementation of the upstream Android Open Source Project .一些特定的兼容性領域是:

  • [C-0-1] Devices MUST NOT change the behavior or semantics of a standard intent.
  • [C-0-2] Devices MUST NOT alter the lifecycle or lifecycle semantics of a particular type of system component (such as Service, Activity, ContentProvider, etc.).
  • [C-0-3] Devices MUST NOT change the semantics of a standard permission.
  • Devices MUST NOT alter the limitations enforced on background applications. More specifically, for background apps:
    • [C-0-4] they MUST stop executing callbacks that are registered by the app to receive outputs from the GnssMeasurement and GnssNavigationMessage .
    • [C-0-5] they MUST rate-limit the frequency of updates that are provided to the app through the LocationManager API class or the WifiManager.startScan() method.
    • [C-0-6] if the app is targeting API level 25 or higher, they MUST NOT allow to register broadcast receivers for the implicit broadcasts of standard Android intents in the app's manifest, unless the broadcast intent requires a "signature" or "signatureOrSystem" protectionLevel permission or are on the exemption list .
    • [C-0-7] if the app is targeting API level 25 or higher, they MUST stop the app's background services, just as if the app had called the services' stopSelf() method, unless the app is placed on a temporary allowlist to handle a task that's visible to the user.
    • [C-0-8] if the app is targeting API level 25 or higher, they MUST release the wakelocks the app holds.
  • [C-0-9] Devices MUST return the following security providers as the first seven array values from the Security.getProviders() method, in the given order and with the given names (as returned by Provider.getName() ) and classes, unless the app has modified the list via insertProviderAt() or removeProvider() . Devices MAY return additional providers after the specified list of providers below.
    1. AndroidNSSP - android.security.net.config.NetworkSecurityConfigProvider
    2. AndroidOpenSSL - com.android.org.conscrypt.OpenSSLProvider
    3. CertPathProvider - sun.security.provider.CertPathProvider
    4. AndroidKeyStoreBCWorkaround - android.security.keystore.AndroidKeyStoreBCWorkaroundProvider
    5. BC - com.android.org.bouncycastle.jce.provider.BouncyCastleProvider
    6. HarmonyJSSE - com.android.org.conscrypt.JSSEProvider
    7. AndroidKeyStore - android.security.keystore.AndroidKeyStoreProvider

上面的列表並不全面。相容性測試套件 (CTS) 測試平台的重要部分(但不是全部)的行為相容性。實作者有責任確保與 Android 開源專案的行為相容性。因此,裝置實現者應該盡可能使用透過 Android 開源專案提供的原始程式碼,而不是重新實作系統的重要部分。

3.5.1. Background Restriction

If device implementations implement the app restrictions that are included in AOSP or extend the app restrictions, they:

  • [C-1-1] MUST provide user affordance where the user can see the list of restricted apps.
  • [C-1-2] MUST provide user affordance to turn on / off the restrictions on each app.
  • [C-1-3] MUST not automatically apply restrictions without evidence of poor system health behavior, but MAY apply the restrictions on apps upon detection of poor system health behavior like stuck wakelocks, long running services, and other criteria. The criteria MAY be determined by device implementers but MUST be related to the app's impact on the system health. Other criteria that are not purely related to the system health, such as the app's lack of popularity in the market, MUST NOT be used as criteria.
  • [C-1-4] MUST not automatically apply app restrictions for apps when a user has turned off app restrictions manually, and MAY suggest the user to apply app restrictions.
  • [C-1-5] MUST inform users if app restrictions are applied to an app automatically.
  • [C-1-6] MUST return true for ActivityManager.isBackgroundRestricted() when the restricted app calls this API.
  • [C-1-7] MUST NOT restrict the top foreground app that is explicitly used by the user.
  • [C-1-8] MUST suspend restrictions on an app that becomes the top foreground application when the user explicitly starts to use the app that used to be restricted.
  • [C-1-9] MUST report all app restriction events via UsageStats . If device implementations extend the app restrictions that are implemented in AOSP, MUST follow the implementation described in this document .

3.6. API命名空間

Android 遵循 Java 程式語言定義的套件和類別命名空間約定。為了確保與第三方應用程式的相容性,裝置實作者不得對這些套件命名空間進行任何禁止的修改(見下文):

  • java.*
  • javax.*
  • sun.*
  • android.*
  • androidx.*
  • com.android.*

That is, they:

  • [C-0-1] MUST NOT modify the publicly exposed APIs on the Android platform by changing any method or class signatures, or by removing classes or class fields.
  • [C-0-2] MUST NOT add any publicly exposed elements (such as classes or interfaces, or fields or methods to existing classes or interfaces) or Test or System APIs to the APIs in the above namespaces. A “publicly exposed element” is any construct that is not decorated with the “@hide” marker as used in the upstream Android source code.

Device implementers MAY modify the underlying implementation of the APIs, but such modifications:

  • [C-0-3] MUST NOT impact the stated behavior and Java-language signature of any publicly exposed APIs.
  • [C-0-4] MUST NOT be advertised or otherwise exposed to developers.

However, device implementers MAY add custom APIs outside the standard Android namespace, but the custom APIs:

  • [C-0-5] MUST NOT be in a namespace owned by or referring to another organization.例如,裝置實作者不得將 API 新增至com.google.*或類似的命名空間:只有 Google 可以做到。同樣,Google 不得將 API 新增至其他公司的命名空間。
  • [C-0-6] MUST be packaged in an Android shared library so that only apps that explicitly use them (via the <uses-library> mechanism) are affected by the increased memory usage of such APIs.

如果設備實現者建議改進上述包命名空間之一(例如透過向現有 API 添加有用的新功能,或添加新 API),則實現者應該訪問source.android.com並開始貢獻更改和的過程代碼,根據該網站上的信息。

請注意,上述限制對應於 Java 程式語言中命名 API 的標準約定;本節的目的只是為了加強這些約定,並透過將其納入此相容性定義來使其具有約束力。

3.7.運行時相容性

設備實現:

  • [C-0-1] MUST support the full Dalvik Executable (DEX) format and Dalvik bytecode specification and semantics .

  • [C-0-2] MUST configure Dalvik runtimes to allocate memory in accordance with the upstream Android platform, and as specified by the following table. (See section 7.1.1 for screen size and screen density definitions.)

  • SHOULD use Android RunTime (ART), the reference upstream implementation of the Dalvik Executable Format, and the reference implementation's package management system.

  • SHOULD run fuzz tests under various modes of execution and target architectures to assure the stability of the runtime. Refer to JFuzz and DexFuzz in the Android Open Source Project website.

Note that memory values specified below are considered minimum values and device implementations MAY allocate more memory per application.

螢幕佈局螢幕密度最小應用記憶體
安卓手錶120 dpi(LDPI) 32MB
140 dpi (140dpi)
160 dpi (mdpi)
180 dpi (180dpi)
200 dpi (200dpi)
213 dpi(電視dpi)
220 dpi (220dpi) 36MB
240 dpi(高清)
280dpi (280dpi)
320 dpi(xhdpi) 48MB
360dpi (360dpi)
400dpi (400dpi) 56MB
420 dpi (420dpi) 64MB
480 dpi (xxhdpi) 88MB
560dpi(560dpi) 112MB
640 dpi (xxxhdpi) 154MB
小/正常120 dpi(LDPI) 32MB
140 dpi (140dpi)
160 dpi (mdpi)
180 dpi (180dpi) 48MB
200 dpi (200dpi)
213 dpi(電視dpi)
220 dpi (220dpi)
240 dpi(高清)
280dpi (280dpi)
320 dpi(xhdpi) 80MB
360dpi (360dpi)
400dpi (400dpi) 96MB
420 dpi (420dpi) 112MB
480 dpi (xxhdpi) 128MB
560dpi(560dpi) 192MB
640 dpi (xxxhdpi) 256MB
大的120 dpi(LDPI) 32MB
140 dpi (140dpi) 48MB
160 dpi (mdpi)
180 dpi (180dpi) 80MB
200 dpi (200dpi)
213 dpi(電視dpi)
220 dpi (220dpi)
240 dpi(高清)
280dpi (280dpi) 96MB
320 dpi(xhdpi) 128MB
360dpi (360dpi) 160MB
400dpi (400dpi) 192MB
420 dpi (420dpi) 228MB
480 dpi (xxhdpi) 256MB
560dpi(560dpi) 384MB
640 dpi (xxxhdpi) 512MB
超大120 dpi(LDPI) 48MB
140 dpi (140dpi) 80MB
160 dpi (mdpi)
180 dpi (180dpi) 96MB
200 dpi (200dpi)
213 dpi(電視dpi)
220 dpi (220dpi)
240 dpi(高清)
280dpi (280dpi) 144MB
320 dpi(xhdpi) 192MB
360dpi (360dpi) 240MB
400dpi (400dpi) 288MB
420 dpi (420dpi) 336MB
480 dpi (xxhdpi) 384MB
560dpi(560dpi) 576MB
640 dpi (xxxhdpi) 768MB

3.8.使用者介面相容性

3.8.1.啟動器(主螢幕)

Android 包括啟動器應用程式(主畫面)並支援第三方應用程式來取代裝置啟動器(主畫面)。

If device implementations allow third-party applications to replace the device home screen, they:

  • [C-1-1] MUST declare the platform feature android.software.home_screen .
  • [C-1-2] MUST return the AdaptiveIconDrawable object when the third-party application use <adaptive-icon> tag to provide their icon, and the PackageManager methods to retrieve icons are called.

If device implementations include a default launcher that supports in-app pinning of shortcuts, they:

Conversely, if device implementations do not support in-app pinning of shortcuts, they:

If device implementations implement a default launcher that provides quick access to the additional shortcuts provided by third-party apps through the ShortcutManager API, they:

  • [C-4-1] MUST support all documented shortcut features (eg static and dynamic shortcuts, pinning shortcuts) and fully implement the APIs of the ShortcutManager API class.

If device implementations include a default launcher app that shows badges for the app icons, they:

  • [C-5-1] MUST respect the NotificationChannel.setShowBadge() API method. In other words, show a visual affordance associated with the app icon if the value is set as true , and do not show any app icon badging scheme when all of the app's notification channels have set the value as false .
  • MAY override the app icon badges with their proprietary badging scheme when third-party applications indicate support of the proprietary badging scheme through the use of proprietary APIs, but SHOULD use the resources and values provided through the notification badges APIs described in the SDK , such as the Notification.Builder.setNumber() and the Notification.Builder.setBadgeIconType() API.

3.8.2.小部件

Android supports third-party app widgets by defining a component type and corresponding API and lifecycle that allows applications to expose an “AppWidget” to the end user.

If device implementations support third-party app widgets, they:

  • [C-1-1] MUST declare support for platform feature android.software.app_widgets .
  • [C-1-2] MUST include built-in support for AppWidgets and expose user interface affordances to add, configure, view, and remove AppWidgets directly within the Launcher.
  • [C-1-3] MUST be capable of rendering widgets that are 4 x 4 in the standard grid size. See the App Widget DesignGuidelines in the Android SDK documentation for details.
  • MAY support application widgets on the lock screen.

If device implementations support third-party app widgets and in-app pinning of shortcuts, they:

3.8.3.通知

Android includes Notification and NotificationManager APIs that allow third-party app developers to notify users of notable events and attract users' attention using the hardware components (eg sound, vibration and light) and software ificlights and softnity the , 系統) 。

3.8.3.1. Presentation of Notifications

If device implementations allow third-party apps to notify users of notable events , they:

  • [C-1-1] MUST support notifications that use hardware features, as described in the SDK documentation, and to the extent possible with the device implementation hardware.例如,如果裝置實作包含振動器,則它必須正確實作振動 API。如果設備實作缺少硬件,則對應的 API 必須實作為無操作。此行為在第 7 節中有進一步詳細介紹。
  • [C-1-2] MUST correctly render all resources (icons, animation files, etc.) provided for in the APIs, or in the Status/System Bar icon style guide , although they MAY provide an alternative user experience for notifications than that provided by the reference Android Open Source implementation.
  • [C-1-3] MUST honor and implement properly the behaviors described for the APIs to update, remove and group notifications.
  • [C-1-4] MUST provide the full behavior of the NotificationChannel API documented in the SDK.
  • [C-1-5] MUST provide a user affordance to block and modify a certain third-party app's notification per each channel and app package level.
  • [C-1-6] MUST also provide a user affordance to display deleted notification channels.
  • [C-1-7] MUST correctly render all resources (images, stickers, icons, etc.) provided through Notification.MessagingStyle alongside the notification text without additional user interaction. For example, MUST show all resources including icons provided through android.app.Person in a group conversation that is set through setGroupConversation .
  • [C-SR] Are STRONGLY RECOMMENDED to automatically surface a user affordance to block a certain third-party app's notification per each channel and app package level after the user dismisses that notification multiple times.
  • SHOULD support rich notifications.
  • SHOULD present some higher priority notifications as heads-up notifications.
  • SHOULD have a user affordance to snooze notifications.
  • MAY only manage the visibility and timing of when third-party apps can notify users of notable events to mitigate safety issues such as driver distraction.

If device implementations support rich notifications, they:

  • [C-2-1] MUST use the exact resources as provided through the Notification.Style API class and its subclasses for the presented resource elements.
  • SHOULD present each and every resource element (eg icon, title and summary text) defined in the Notification.Style API class and its subclasses.

If device implementations support heads-up notifications: they:

  • [C-3-1] MUST use the heads-up notification view and resources as described in the Notification.Builder API class when heads-up notifications are presented.
  • [C-3-2] MUST display the actions provided through Notification.Builder.addAction() together with the notification content without additional user interaction as described in the SDK .
3.8.3.2. Notification Listener Service

Android includes the NotificationListenerService APIs that allow apps (once explicitly enabled by the user) to receive a copy of all notifications as they are posted or updated.

If device implementations report the feature flag android.hardware.ram.normal , they:

  • [C-1-1] MUST correctly and promptly update notifications in their entirety to all such installed and user-enabled listener services, including any and all metadata attached to the Notification object.
  • [C-1-2] MUST respect the snoozeNotification() API call, and dismiss the notification and make a callback after the snooze duration that is set in the API call.

If device implementations have a user affordance to snooze notifications, they:

  • [C-2-1] MUST reflect the snoozed notification status properly through the standard APIs such as NotificationListenerService.getSnoozedNotifications() .
  • [C-2-2] MUST make this user affordance available to snooze notifications from each installed third-party app's, unless they are from persistent/foreground services.
3.8.3.3. DND (Do not Disturb)

If device implementations support the DND feature, they:

  • [C-1-1] MUST implement an activity that would respond to the intent ACTION_NOTIFICATION_POLICY_ACCESS_SETTINGS , which for implementations with UI_MODE_TYPE_NORMAL it MUST be an activity where the user can grant or deny the app access to DND policy configurations.
  • [C-1-2] MUST, for when the device implementation has provided a means for the user to grant or deny third-party apps to access the DND policy configuration, display Automatic DND rules created by applications alongside the user-created and pre-defined rules.
  • [C-1-3] MUST honor the suppressedVisualEffects values passed along the NotificationManager.Policy and if an app has set any of the SUPPRESSED_EFFECT_SCREEN_OFF or SUPPRESSED_EFFECT_SCREEN_ON flags, it SHOULD indicate to the user that the visual effects are suppressed in the DND settings menu.

Android 包含的 API 允許開發人員將搜尋合併到他們的應用程式中,並將應用程式的資料公開到全域系統搜尋中。一般來說,此功能由單一系統範圍的使用者介面組成,允許使用者輸入查詢、在使用者鍵入時顯示建議並顯示結果。 Android API 允許開發人員重複使用此介面在自己的應用程式中提供搜索,並允許開發人員向通用全域搜尋使用者介面提供結果。

  • Android 裝置實作應該包括全域搜索,這是一個單一的、共享的、系統範圍的搜尋使用者介面,能夠響應用戶輸入提供即時建議。

If device implementations implement the global search interface, they:

  • [C-1-1] MUST implement the APIs that allow third-party applications to add suggestions to the search box when it is run in global search mode.

If no third-party applications are installed that make use of the global search:

  • The default behavior SHOULD be to display web search engine results and suggestions.

Android 還包含Assist API ,允許應用程式選擇與裝置上的助理共享當前上下文的多少資訊。

If device implementations support the Assist action, they:

  • [C-2-1] MUST indicate clearly to the end user when the context is shared, by either:
    • Each time the assist app accesses the context, displaying a white light around the edges of the screen that meet or exceed the duration and brightness of the Android Open Source Project implementation.
    • For the preinstalled assist app, providing a user affordance less than two navigations away from the default voice input and assistant app settings menu , and only sharing the context when the assist app is explicitly invoked by the user through a hotword or assist navigation key input.
  • [C-2-2] The designated interaction to launch the assist app as described in section 7.2.3 MUST launch the user-selected assist app, in other words the app that implements VoiceInteractionService , or an activity handling the ACTION_ASSIST intent.

3.8.5。 Alerts and Toasts

Applications can use the Toast API to display short non-modal strings to the end user that disappear after a brief period of time, and use the TYPE_APPLICATION_OVERLAY window type API to display alert windows as an overlay over other apps.

If device implementations include a screen or video output, they:

  • [C-1-1] MUST provide a user affordance to block an app from displaying alert windows that use the TYPE_APPLICATION_OVERLAY . The AOSP implementation meets this requirement by having controls in the notification shade.

  • [C-1-2] MUST honor the Toast API and display Toasts from applications to end users in some highly visible manner.

3.8.6。主題

Android 提供「主題」作為應用程式在整個 Activity 或應用程式中應用樣式的機制。

Android includes a “Holo” and "Material" theme family as a set of defined styles for application developers to use if they want to match the Holo theme look and feel as defined by the Android SDK.

If device implementations include a screen or video output, they:

  • [C-1-1] MUST NOT alter any of the Holo theme attributes exposed to applications.
  • [C-1-2] MUST support the “Material” theme family and MUST NOT alter any of the Material theme attributes or their assets exposed to applications.

Android 還包含一個「裝置預設」主題系列,作為一組定義的樣式,供應用程式開發人員在想要匹配裝置實現者定義的裝置主題的外觀和風格時使用。

Android 支援具有半透明系統列的變體主題,允許應用程式開發人員使用其應用程式內容填充狀態列和導覽列後面的區域。為了在此配置中實現一致的開發人員體驗,在不同的裝置實作中保持狀態列圖示樣式非常重要。

If device implementations include a system status bar, they:

  • [C-2-1] MUST use white for system status icons (such as signal strength and battery level) and notifications issued by the system, unless the icon is indicating a problematic status or an app requests a unless the icon is indicating a problematic status or an app requests a unless 保險。
  • [C-2-2] Android device implementations MUST change the color of the system status icons to black (for details, refer to R.style ) when an app requests a light status bar.

3.8.7.動態壁紙

Android 定義了一種元件類型以及相應的 API 和生命週期,允許應用程式向最終用戶公開一個或多個「動態桌布」 。動態壁紙是動畫、圖案或具有有限輸入功能的類似圖像,在其他應用程式後面顯示為壁紙。

如果硬體能夠以合理的幀速率運行所有動態壁紙,且沒有功能限制,並且不會對其他應用程式產生不利影響,則該硬體被認為能夠可靠地運行動態壁紙。如果硬體限制導致壁紙和/或應用程式崩潰、故障、消耗過多的 CPU 或電池電量,或以不可接受的低幀速率運行,則該硬體被視為無法運行動態壁紙。例如,某些動態桌布可能使用 OpenGL 2.0 或 3.x 上下文來渲染其內容。動態桌布將無法在不支援多個 OpenGL 上下文的硬體上可靠地運行,因為使用 OpenGL 上下文的動態桌布可能會與也使用 OpenGL 上下文的其他應用程式發生衝突。

  • 如上所述,能夠可靠地運行即時壁紙的設備實現應實現即時壁紙。

If device implementations implement live wallpapers, they:

  • [C-1-1] MUST report the platform feature flag android.software.live_wallpaper.

3.8.8。活動切換

上游 Android 原始程式碼包括概覽畫面、系統級使用者介面,用於任務切換以及使用使用者上次離開應用程式時應用程式圖形狀態的縮圖顯示最近造訪的活動和任務。

Device implementations including the recents function navigation key as detailed in section 7.2.3 MAY alter the interface.

If device implementations including the recents function navigation key as detailed in section 7.2.3 alter the interface, they:

  • [C-1-1] MUST support at least up to 7 displayed activities.
  • 應至少一次顯示 4 個活動的標題。
  • [C-1-2] MUST implement the screen pinning behavior and provide the user with a settings menu to toggle the feature.
  • 應顯示最近的突出顯示顏色、圖示、螢幕標題。
  • 應顯示關閉可供性(“x”),但可以延遲顯示,直到使用者與螢幕互動。
  • SHOULD implement a shortcut to switch easily to the previous activity.
  • 當最近使用的功能鍵被點擊兩次時,應該會觸發兩個最近使用的應用程式之間的快速切換操作。
  • 當長按最近使用的功能鍵時,如果支持,應該觸發分割畫面多視窗模式。
  • 可以將關聯的最近內容顯示為一起移動的群組。
  • [SR] Are STRONGLY RECOMMENDED to use the upstream Android user interface (or a similar thumbnail-based interface) for the overview screen.

3.8.9。輸入管理

Android 包括對輸入管理的支援以及對第三方輸入法編輯器的支援。

If device implementations allow users to use third-party input methods on the device, they:

  • [C-1-1] MUST declare the platform feature android.software.input_methods and support IME APIs as defined in the Android SDK documentation.
  • [C-1-2] MUST provide a user-accessible mechanism to add and configure third-party input methods in response to the android.settings.INPUT_METHOD_SETTINGS intent.

If device implementations declare the android.software.autofill feature flag, they:

3.8.10.鎖定螢幕媒體控制

從 Android 5.0 開始,遠端控制用戶端 API 已被棄用,取而代之的是媒體通知模板,該模板允許媒體應用程式與鎖定螢幕上顯示的播放控制項整合。

3.8.11.螢幕保護程式(以前的夢想)

Android includes support for interactive screen savers , previously referred to as Dreams.當連接到電源的裝置空閒或停靠在桌面擴充座時,螢幕保護程式允許使用者與應用程式互動。 Android Watch devices MAY implement screen savers, but other types of device implementations SHOULD include support for screen savers and provide a settings option for users to configure screen savers in response to the android.settings.DREAM_SETTINGS intent.

3.8.12.地點

If device implementations include a hardware sensor (eg GPS) that is capable of providing the location coordinates, they

3.8.13.統一碼和字體

Android includes support for the emoji characters defined in Unicode 10.0 .

If device implementations include a screen or video output, they:

  • [C-1-1] MUST be capable of rendering these emoji characters in color glyph.
  • [C-1-2] MUST include support for:
    • Roboto 2 font with different weights—sans-serif-thin, sans-serif-light, sans-serif-medium, sans-serif-black, sans-serif-condensed, sans-serif-condensed-light for the languages available on the裝置.
    • Full Unicode 7.0 coverage of Latin, Greek, and Cyrillic, including the Latin Extended A, B, C, and D ranges, and all glyphs in the currency symbols block of Unicode 7.0.
  • SHOULD support the skin tone and diverse family emojis as specified in the Unicode Technical Report #51 .

If device implementations include an IME, they:

  • SHOULD provide an input method to the user for these emoji characters.

Android includes support to render Myanmar fonts. Myanmar has several non-Unicode compliant fonts, commonly known as “Zawgyi,” for rendering Myanmar languages.

If device implementations include support for Burmese, they:

* [C-2-1] MUST render text with Unicode compliant font as default;
  non-Unicode compliant font MUST NOT be set as default font unless the user
  chooses it in the language picker.
* [C-2-2] MUST support a Unicode font and a non-Unicode compliant font if a
  non-Unicode compliant font is supported on the device.  Non-Unicode
  compliant font MUST NOT remove or overwrite the Unicode font.
* [C-2-3] MUST render text with non-Unicode compliant font ONLY IF a
  language code with [script code Qaag](
  http://unicode.org/reports/tr35/#unicode_script_subtag_validity) is
  specified (e.g. my-Qaag). No other ISO language or region codes (whether
  assigned, unassigned, or reserved) can be used to refer to non-Unicode
  compliant font for Myanmar. App developers and web page authors can
  specify my-Qaag as the designated language code as they would for any
  other language.

3.8.14.多視窗

If device implementations have the capability to display multiple activities at the same time, they:

  • [C-1-1] MUST implement such multi-window mode(s) in accordance with the application behaviors and APIs described in the Android SDK multi-window mode support documentation and meet the following requirements:
  • [C-1-2] MUST honor android:resizeableActivity that is set by an app in the AndroidManifest.xml file as described in this SDK .
  • [C-1-3] MUST NOT offer split-screen or freeform mode if the screen height is less than 440 dp and the screen width is less than 440 dp.
  • [C-1-4] An activity MUST NOT be resized to a size smaller than 220dp in multi-window modes other than picture-in-picture.
  • 螢幕尺寸xlarge裝置實作應該支援自由格式模式。

If device implementations support multi-window mode(s), and the split screen mode, they:

  • [C-2-1] MUST preload a resizeable launcher as the default.
  • [C-2-2] MUST crop the docked activity of a split-screen multi-window but SHOULD show some content of it, if the Launcher app is the focused window.
  • [C-2-3] MUST honor the declared AndroidManifestLayout_minWidth and AndroidManifestLayout_minHeight values of the third-party launcher application and not override these values in the course of showing some content of the docked activity.

If device implementations support multi-window mode(s) and picture-in-picture multi-window mode, they:

  • [C-3-1] MUST launch activities in picture-in-picture multi-window mode when the app is: * Targeting API level 26 or higher and declares android:supportsPictureInPicture * Targeting API level 25 or lower and declares both android:resizeableActivity and android:supportsPictureInPicture .
  • [C-3-2] MUST expose the actions in their SystemUI as specified by the current PIP activity through the setActions() API.
  • [C-3-3] MUST support aspect ratios greater than or equal to 1:2.39 and less than or equal to 2.39:1, as specified by the PIP activity through the setAspectRatio() API.
  • [C-3-4] MUST use KeyEvent.KEYCODE_WINDOW to control the PIP window; if PIP mode is not implemented, the key MUST be available to the foreground activity.
  • [C-3-5] MUST provide a user affordance to block an app from displaying in PIP mode; the AOSP implementation meets this requirement by having controls in the notification shade.
  • [C-3-6] MUST allocate minimum width and height of 108 dp for the PIP window and minimum width of 240 dp and height of 135 dp for the PIP window when the Configuration.uiMode is configured as UI_MODE_TYPE_TELEVISION .

3.8.15。 Display Cutout

Android supports a Display Cutout as described in the SDK document. The DisplayCutout API defines an area on the edge of the display that is not functional for displaying content.

If device implementations include display cutout(s), they:

  • [C-1-1] MUST only have cutout(s) on the short edge(s) of the device. Conversely, if the device's aspect ratio is 1.0(1:1), they MUST NOT have cutout(s).
  • [C-1-2] MUST NOT have more than one cutout per edge.
  • [C-1-3] MUST honor the display cutout flags set by the app through the WindowManager.LayoutParams API as described in the SDK.
  • [C-1-4] MUST report correct values for all cutout metrics defined in the DisplayCutout API.

3.9.設備管理

Android 包含允許安全感知應用程式在系統層級執行裝置管理功能的功能,例如透過Android 裝置管理 API強制執行密碼原則或執行遠端清除。

If device implementations implement the full range of device administration policies defined in the Android SDK documentation, they:

  • [C-1-1] MUST declare android.software.device_admin .
  • [C-1-2] MUST support device owner provisioning as described in section 3.9.1 and section 3.9.1.1 .

3.9.1 準備配置

3.9.1.1 設備所有者配置

If device implementations declare android.software.device_admin , they:

  • [C-1-1] MUST support enrolling a Device Policy Client (DPC) as a Device Owner app as described below:
  • [C-1-2] MUST require some affirmative action during the provisioning process to consent to the app being set as Device Owner. Consent can be via user action or by some programmatic means during provisioning but it MUST NOT be hard coded or prevent the use of other Device Owner apps.

If device implementations declare android.software.device_admin , but also include a proprietary Device Owner management solution and provide a mechanism to promote an application configured in their solution as a "Device Owner equivalent" to the standard "Device Owner" as recognized by the standard Android DevicePolicyManager APIs, they:

  • [C-2-1] MUST have a process in place to verify that the specific app being promoted belongs to a legitimate enterprise device management solution and it has been already configured in the proprietary solution to have the right equist" 。
  • [C-2-2] MUST show the same AOSP Device Owner consent disclosure as the flow initiated by android.app.action.PROVISION_MANAGED_DEVICE prior to enrolling the DPC application as "Device Owner".
  • MAY have user data on the device prior to enrolling the DPC application as "Device Owner".
3.9.1.2 託管設定檔配置

If device implementations declare android.software.managed_users , they:

  • [C-1-1] MUST implement the APIs allowing a Device Policy Controller (DPC) application to become the owner of a new Managed Profile .

  • [C-1-2] The managed profile provisioning process (the flow initiated by android.app.action.PROVISION_MANAGED_PROFILE ) users experience MUST align with the AOSP implementation.

  • [C-1-3] MUST provide the following user affordances within the Settings to indicate to the user when a particular system function has been disabled by the Device Policy Controller (DPC):

    • 一致的圖示或其他使用者可供性(例如上游 AOSP 資訊圖示),用於表示特定設定何時受到設備管理員的限制。
    • 簡短的解釋訊息,由設備管理員透過setShortSupportMessage提供。
    • DPC 應用程式的圖示。

3.9.2 託管設定檔支持

If device implementations declare android.software.managed_users , they:

  • [C-1-1] MUST support managed profiles via the android.app.admin.DevicePolicyManager APIs.
  • [C-1-2] MUST allow one and only one managed profile to be created .
  • [C-1-3] MUST use an icon badge (similar to the AOSP upstream work badge) to represent the managed applications and widgets and other badged UI elements like Recents & Notifications.
  • [C-1-4] MUST display a notification icon (similar to the AOSP upstream work badge) to indicate when user is within a managed profile application.
  • [C-1-5] MUST display a toast indicating that the user is in the managed profile if and when the device wakes up (ACTION_USER_PRESENT) and the foreground application is within the managed profile.
  • [C-1-6] Where a managed profile exists, MUST show a visual affordance in the Intent 'Chooser' to allow the user to forward the intent from the managed profile to the primary user or vice versa, if enable Polid by the Device or vice versa, if enable Polid by the Device or vice versa, if enable Poli控制器。
  • [C-1-7] Where a managed profile exists, MUST expose the following user affordances for both the primary user and the managed profile:
    • 單獨核算主要使用者和託管設定檔的電池、位置、行動資料和儲存使用情況。
    • 獨立管理安裝在主要使用者或託管設定檔中的 VPN 應用程式。
    • 獨立管理安裝在主用戶或託管設定檔中的應用程式。
    • 對主要使用者或託管設定檔中的帳戶進行獨立管理。
  • [C-1-8] MUST ensure the preinstalled dialer, contacts and messaging applications can search for and look up caller information from the managed profile (if one exists) alongside those from the primary profile, if the Device Policy Controller permits it.
  • [C-1-9] MUST ensure that it satisfies all the security requirements applicable for a device with multiple users enabled (see section 9.5 ), even though the managed profile is not counted as another user in addition to the primary user.
  • [C-1-10] MUST support the ability to specify a separate lock screen meeting the following requirements to grant access to apps running in a managed profile.
  • 當託管設定檔中的聯絡人顯示在預先安裝的通話記錄、通話中UI、正在進行和未接來電通知、聯絡人和訊息應用程式中時,他們應該使用與指示託管設定檔應用程式相同的徽章。

3.9.3 Managed User Support

If device implementations declare android.software.managed_users , they:

  • [C-1-1] MUST provide a user affordance to logout from the current user and switch back to the primary user in multiple-user session when isLogoutEnabled returns true . The user affordance MUST be accessible from the lockscreen without unlocking the device.

3.10.無障礙

Android 提供了一個輔助功能層,可以幫助殘障用戶更輕鬆地導航其裝置。此外,Android 還提供平台 API,使輔助功能服務實現能夠接收使用者和系統事件的回調,並產生備用回饋機制,例如文字轉語音、觸覺回饋和軌跡球/方向鍵導航。

If device implementations support third-party accessibility services, they:

  • [C-1-1] MUST provide an implementation of the Android accessibility framework as described in the accessibility APIs SDK documentation.
  • [C-1-2] MUST generate accessibility events and deliver the appropriate AccessibilityEvent to all registered AccessibilityService implementations as documented in the SDK.
  • [C-1-3] MUST honor the android.settings.ACCESSIBILITY_SETTINGS intent to provide a user-accessible mechanism to enable and disable the third-party accessibility services alongside the preinstalled accessibility services.
  • [C-1-4] MUST add a button in the system's navigation bar allowing the user to control the accessibility service when the enabled accessibility services declare the AccessibilityServiceInfo.FLAG_REQUEST_ACCESSIBILITY_BUTTON . Note that for device implementations with no system navigation bar, this requirement is not applicable, but device implementations SHOULD provide a user affordance to control these accessibility services.

If device implementations include preinstalled accessibility services, they:

  • [C-2-1] MUST implement these preinstalled accessibility services as Direct Boot Aware apps when the data storage is encrypted with File Based Encryption (FBE).
  • SHOULD provide a mechanism in the out-of-box setup flow for users to enable relevant accessibility services, as well as options to adjust the font size, display size and magnification gestures.

3.11.文字轉語音

Android 包含的 API 允許應用程式使用文字轉語音 (TTS) 服務,並允許服務提供者提供 TTS 服務的實作。

If device implementations reporting the feature android.hardware.audio.output, they:

If device implementations support installation of third-party TTS engines, they:

  • [C-2-1] MUST provide user affordance to allow the user to select a TTS engine for use at system level.

3.12.電視輸入框架

Android Television 輸入框架 (TIF)簡化了向 Android Television 裝置交付即時內容的過程。 TIF 提供標準 API 來建立控制 Android Television 裝置的輸入模組。

If device implementations support TIF, they:

  • [C-1-1] MUST declare the platform feature android.software.live_tv .
  • [C-1-2] MUST support all TIF APIs such that an application which uses these APIs and the third-party TIF-based inputs service can be installed and used on the device.

3.13.快速設定

Android provides a Quick Settings UI component that allows quick access to frequently used or urgently needed actions.

If device implementations include a Quick Settings UI component, they:

  • [C-1-1] MUST allow the user to add or remove the tiles provided through the quicksettings APIs from a third-party app.
  • [C-1-2] MUST NOT automatically add a tile from a third-party app directly to the Quick Settings.
  • [C-1-3] MUST display all the user-added tiles from third-party apps alongside the system-provided quick setting tiles.

3.14。媒體介面

If device implementations include non-voice-activated applications (the Apps) that interact with third-party applications through MediaBrowser or MediaSession , the Apps:

  • [C-1-2] MUST clearly display icons obtained via getIconBitmap() or getIconUri() and titles obtained via getTitle() as described in MediaDescription . May shorten titles to comply with safety regulations (eg driver distraction).

  • [C-1-3] MUST show the third-party application icon whenever displaying content provided by this third-party application.

  • [C-1-4] MUST allow the user to interact with the entire MediaBrowser hierarchy. MAY restrict the access to part of the hierarchy to comply with safety regulations (eg driver distraction), but MUST NOT give preferential treatment based on content or content provider.

  • [C-1-5] MUST consider double tap of KEYCODE_HEADSETHOOK or KEYCODE_MEDIA_PLAY_PAUSE as KEYCODE_MEDIA_NEXT for MediaSession.Callback#onMediaButtonEvent .

3.15。 Instant Apps

Device implementations MUST satisfy the following requirements:

  • [C-0-1] Instant Apps MUST only be granted permissions that have the android:protectionLevel set to "instant" .
  • [C-0-2] Instant Apps MUST NOT interact with installed apps via implicit intents unless one of the following is true:
    • The component's intent pattern filter is exposed and has CATEGORY_BROWSABLE
    • The action is one of ACTION_SEND, ACTION_SENDTO, ACTION_SEND_MULTIPLE
    • The target is explicitly exposed with android:visibleToInstantApps
  • [C-0-3] Instant Apps MUST NOT interact explicitly with installed apps unless the component is exposed via android:visibleToInstantApps.
  • [C-0-4] Installed Apps MUST NOT see details about Instant Apps on the device unless the Instant App explicitly connects to the installed application.
  • Device implementations MUST provide the following user affordances for interacting with Instant Apps. The AOSP meets the requirements with the default System UI, Settings, and Launcher.設備實現:
    • [C-0-5] MUST provide a user affordance to view and delete Instant Apps locally cached for each individual app package.
    • [C-0-6] MUST provide a persistent user notification that can be collapsed while an Instant App is running in the foreground. This user notification MUST include that Instant Apps do not require installation and provide a user affordance that directs the user to the application info screen in Settings. For Instant Apps launched via web intents, as defined by using an intent with action set to Intent.ACTION_VIEW and with a scheme of "http" or "https", an additional user affordance SHOULD allow the user not to launch the Instant App and launch the associated link with the configured web browser, if a browser is available on the device.
    • [C-0-7] MUST allow running Instant Apps to be accessed from the Recents function if the Recents function is available on the device.

3.16。 Companion Device Pairing

Android includes support for companion device pairing to more effectively manage association with companion devices and provides the CompanionDeviceManager API for apps to access this feature.

If device implementations support the companion device pairing feature, they:

  • [C-1-1] MUST declare the feature flag FEATURE_COMPANION_DEVICE_SETUP .
  • [C-1-2] MUST ensure the APIs in the android.companion package is fully implemented.
  • [C-1-3] MUST provide user affordances for the user to select/confirm a companion device is present and operational.

3.17。 Heavyweight Apps

If device implementations declare the feature FEATURE_CANT_SAVE_STATE , then they:

  • [C-1-1] MUST have only one installed app that specifies cantSaveState running in the system at a time. If the user leaves such an app without explicitly exiting it (for example by pressing home while leaving an active activity the system, instead of pressing back with no remaining active activities in the system), then device implementations MUST prioritize that app in RAM as they do for other things that are expected to remain running, such as foreground services. While such an app is in the background, the system can still apply power management features to it, such as limiting CPU and network access.
  • [C-1-2] MUST provide a UI affordance to chose the app that won't participate in the normal state save/restore mechanism once the user launches a second app declared with cantSaveState attribute.
  • [C-1-3] MUST NOT apply other changes in policy to apps that specify cantSaveState , such as changing CPU performance or changing scheduling prioritization.

If device implementations don't declare the feature FEATURE_CANT_SAVE_STATE , then they:

  • [C-1-1] MUST ignore the cantSaveState attribute set by apps and MUST NOT change the app behavior based on that attribute.

4. 應用程式封裝相容性

Devices implementations:

  • [C-0-1] MUST be capable of installing and running Android “.apk” files as generated by the “aapt” tool included in the official Android SDK .
  • As the above requirement may be challenging, device implementations are RECOMMENDED to use the AOSP reference implementation's package management system.

設備實現:

  • [C-0-2] MUST support verifying “.apk” files using the APK Signature Scheme v3 , APK Signature Scheme v2 and JAR signing .
  • [C-0-3] MUST NOT extend either the .apk , Android Manifest , Dalvik bytecode , or RenderScript bytecode formats in such a way that would prevent those files from installing and running correctly on other compatible devices.
  • [C-0-4] MUST NOT allow apps other than the current "installer of record" for the package to silently uninstall the app without any user confirmation, as documented in the SDK for the DELETE_PACKAGE permission. The only exceptions are the system package verifier app handling PACKAGE_NEEDS_VERIFICATION intent and the storage manager app handling ACTION_MANAGE_STORAGE intent.

  • [C-0-5] MUST have an activity that handles the android.settings.MANAGE_UNKNOWN_APP_SOURCES intent.

  • [C-0-6] MUST NOT install application packages from unknown sources, unless the app that requests the installation meets all the following requirements:

    • It MUST declare the REQUEST_INSTALL_PACKAGES permission or have the android:targetSdkVersion set at 24 or lower.
    • It MUST have been granted permission by the user to install apps from unknown sources.
  • SHOULD provide a user affordance to grant/revoke the permission to install apps from unknown sources per application, but MAY choose to implement this as a no-op and return RESULT_CANCELED for startActivityForResult() , if the device implementation does not want to allow users to have this choice. However, even in such cases, they SHOULD indicate to the user why there is no such choice presented.

  • [C-0-7] MUST display a warning dialog with the warning string that is provided through the system API PackageManager.setHarmfulAppWarning to the user before launching an activity in an application that has been mark before launching an PackageManager.setHarmfulAppWarning in an application that has been marked 之前有害。

  • SHOULD provide a user affordance to choose to uninstall or launch an application on the warning dialog.

5. 多媒體相容性

設備實現:

  • [C-0-1] MUST support the media formats, encoders, decoders, file types, and container formats defined in section 5.1 for each and every codec declared by MediaCodecList .
  • [C-0-2] MUST declare and report support of the encoders, decoders available to third-party applications via MediaCodecList .
  • [C-0-3] MUST be able to properly decode and make available to third-party apps all the formats it can encode. This includes all bitstreams that its encoders generate and the profiles reported in its CamcorderProfile .

設備實現:

  • SHOULD aim for minimum codec latency, in others words, they
    • SHOULD NOT consume and store input buffers and return input buffers only once processed.
    • 保留解碼緩衝區的時間不應超過標準(例如 SPS)指定的時間。
    • 保留編碼緩衝區的時間不應超過 GOP 結構所需的時間。

All of the codecs listed in the section below are provided as software implementations in the preferred Android implementation from the Android Open Source Project.

請注意,Google 和開放手機聯盟均未聲明這些編解碼器不受第三方專利的影響。打算在硬體或軟體產品中使用此原始碼的人請注意,此程式碼的實現(包括在開源軟體或共享軟體中)可能需要相關專利持有者的專利許可。

5.1.媒體編解碼器

5.1.1. Audio Encoding

See more details in 5.1.3. Audio Codecs Details .

If device implementations declare android.hardware.microphone , they MUST support encoding the following audio formats and make them available to third-party apps:

  • [C-1-1] PCM/WAVE
  • [C-1-2] FLAC
  • [C-1-3] Opus

All audio encoders MUST support:

5.1.2. Audio Decoding

See more details in 5.1.3. Audio Codecs Details .

If device implementations declare support for the android.hardware.audio.output feature, they MUST support decoding the following audio formats:

  • [C-1-1] MPEG-4 AAC Profile (AAC LC)
  • [C-1-2] MPEG-4 HE AAC Profile (AAC+)
  • [C-1-3] MPEG-4 HE AACv2 Profile (enhanced AAC+)
  • [C-1-4] AAC ELD (enhanced low delay AAC)
  • [C-1-11] xHE-AAC (ISO/IEC 23003-3 Extended HE AAC Profile, which includes the USAC Baseline Profile, and ISO/IEC 23003-4 Dynamic Range Control Profile)
  • [C-1-5] FLAC
  • [C-1-6] MP3
  • [C-1-7] MIDI
  • [C-1-8] Vorbis
  • [C-1-9] PCM/WAVE including high-resolution audio formats up to 24 bits, 192 kHz sample rate, and 8 channels. Note that this requirement is for decoding only, and that a device is permitted to downsample and downmix during the playback phase.
  • [C-1-10] Opus

If device implementations support the decoding of AAC input buffers of multichannel streams (ie more than two channels) to PCM through the default AAC audio decoder in the android.media.MediaCodec API, the following MUST be supported:

  • [C-2-1] Decoding MUST be performed without downmixing (eg a 5.0 AAC stream MUST be decoded to five channels of PCM, a 5.1 AAC stream MUST be decoded to six channels of PCM).
  • [C-2-2] Dynamic range metadata MUST be as defined in "Dynamic Range Control (DRC)" in ISO/IEC 14496-3, and the android.media.MediaFormat DRC keys to configure the dynamic range-related behaviors of the audio decoder. The AAC DRC keys were introduced in API 21, and are: KEY_AAC_DRC_ATTENUATION_FACTOR , KEY_AAC_DRC_BOOST_FACTOR , KEY_AAC_DRC_HEAVY_COMPRESSION , KEY_AAC_DRC_TARGET_REFERENCE_LEVEL and KEY_AAC_ENCODED_TARGET_LEVEL .
  • [SR] It is STRONGLY RECOMMENDED that requirements C-2-1 and C-2-2 above are satisfied by all AAC audio decoders.

When decoding USAC audio, MPEG-D (ISO/IEC 23003-4):

  • [C-3-1] Loudness and DRC metadata MUST be interpreted and applied according to MPEG-D DRC Dynamic Range Control Profile Level 1.
  • [C-3-2] The decoder MUST behave according to the configuration set with the following android.media.MediaFormat keys: KEY_AAC_DRC_TARGET_REFERENCE_LEVEL and KEY_AAC_DRC_EFFECT_TYPE .

MPEG-4 AAC, HE AAC, and HE AACv2 profile decoders:

  • MAY support loudness and dynamic range control using ISO/IEC 23003-4 Dynamic Range Control Profile.

If ISO/IEC 23003-4 is supported and if both ISO/IEC 23003-4 and ISO/IEC 14496-3 metadata are present in a decoded bitstream, then:

  • ISO/IEC 23003-4 metadata SHALL take precedence.

All audio decoders MUST support outputting:

5.1.3. Audio Codecs Details

格式/編解碼器細節File Types/Container Formats to be supported
MPEG-4 AAC 設定文件
(AAC LC)
Support for mono/stereo/5.0/5.1 content with standard sampling rates from 8 to 48 kHz.
  • 3GPP (.3gp)
  • MPEG-4(.mp4、.m4a)
  • ADTS raw AAC (.aac, ADIF not supported)
  • MPEG-TS (.ts, not seekable, decode only)
  • Matroska (.mkv, decode only)
MPEG-4 HE AAC 設定檔 (AAC+) Support for mono/stereo/5.0/5.1 content with standard sampling rates from 16 to 48 kHz.
  • 3GPP (.3gp)
  • MPEG-4(.mp4、.m4a)
MPEG-4 HE AACv2
設定檔(增強型 AAC+)
Support for mono/stereo/5.0/5.1 content with standard sampling rates from 16 to 48 kHz.
  • 3GPP (.3gp)
  • MPEG-4(.mp4、.m4a)
AAC ELD(增強型低延遲AAC)支援單聲道/立體聲內容,標準取樣率為 16 至 48 kHz。
  • 3GPP (.3gp)
  • MPEG-4(.mp4、.m4a)
USAC Support for mono/stereo content with standard sampling rates from 7.35 to 48 kHz. MPEG-4(.mp4、.m4a)
AMR-NB 8 kHz 時取樣率為 4.75 至 12.2 kbps 3GPP (.3gp)
AMR-WB 9 rates from 6.60 kbit/s to 23.85 kbit/s sampled @ 16 kHz, as defined at AMR-WB, Adaptive Multi-Rate - Wideband Speech Codec 3GPP (.3gp)
FLAC For both encoder and decoder: at least Mono and Stereo modes MUST be supported. Sample rates up to 192 kHz MUST be supported; 16-bit and 24-bit resolution MUST be supported. FLAC 24-bit audio data handling MUST be available with floating point audio configuration.
  • FLAC (.flac)
  • MPEG-4 (.mp4, .m4a, decode only)
  • Matroska (.mkv, decode only)
MP3單聲道/立體聲 8-320Kbps 恆定 (CBR) 或可變位元速率 (VBR)
  • MP3 (.mp3)
  • MPEG-4 (.mp4, .m4a, decode only)
  • Matroska (.mkv, decode only)
MIDI MIDI 類型 0 和 1。DLS 版本 1 和 2。XMF 和 Mobile XMF。支援鈴聲格式 RTTTL/RTX、OTA 和 iMelody
  • 類型 0 和 1(.mid、.xmf、.mxmf)
  • RTTTL/RTX(.rtttl、.rtx)
  • OTA (.ota)
  • iMelody (.imy)
沃爾比斯
  • 奧格 (.ogg)
  • MPEG-4 (.mp4, .m4a, decode only)
  • Matroska (.mkv)
  • Webm (.webm)
PCM/波PCM codec MUST support 16-bit linear PCM and 16-bit float. WAVE extractor MUST support 16-bit, 24-bit, 32-bit linear PCM and 32-bit float (rates up to limit of hardware). Sampling rates MUST be supported from 8 kHz to 192 kHz.波形 (.wav)
作品
  • 奧格 (.ogg)
  • MPEG-4 (.mp4, .m4a, decode only)
  • Matroska (.mkv)
  • Webm (.webm)

5.1.4. Image Encoding

See more details in 5.1.6. Image Codecs Details .

Device implementations MUST support encoding the following image encoding:

  • [C-0-1] JPEG
  • [C-0-2] PNG
  • [C-0-3] WebP

If device implementations support HEIC encoding via android.media.MediaCodec for media type MIMETYPE_IMAGE_ANDROID_HEIC , they:

5.1.5。 Image Decoding

See more details in 5.1.6. Image Codecs Details .

Device implementations MUST support decoding the following image encoding:

  • [C-0-1] JPEG
  • [C-0-2] GIF
  • [C-0-3] PNG
  • [C-0-4] BMP
  • [C-0-5] WebP
  • [C-0-6] Raw
  • [C-0-7] HEIF (HEIC)

Image decoders that support a high bit-depth format (9+ bits per channel)

  • [C-1-1] MUST support outputting an 8-bit equivalent format if requested by the application, for example, via the ARGB_8888 config of android.graphics.Bitmap .

5.1.6。 Image Codecs Details

格式/編解碼器細節支援的文件類型/容器格式
JPEG基礎+漸進式jpeg(.jpg)
動圖gif(.gif)
巴布亞紐幾內亞PNG (.png)
骨形態發生蛋白BMP(.bmp)
網路P WebP(.WEBP)
生的ARW(.ARW),CR2(.CR2),DNG(.DNG),NEF(.NEF),NRW(.NRW),ORF(.orf),PEF(.pef(.pef),raf(.raf( .raf),rw2(rw2),rw2(rw2)( .rw2),srw(.srw)
海伊夫Image, Image collection, Image sequence HEIF (.heif), HEIC (.heic)

Image encoder and decoders exposed through the MediaCodec API

  • [C-1-1] MUST support YUV420 8:8:8 flexible color format ( COLOR_FormatYUV420Flexible ) through CodecCapabilities .

  • [SR] STRONGLY RECOMMENDED to support RGB888 color format for input Surface mode.

  • [C-1-3] MUST support at least one of a planar or semiplanar YUV420 8:8:8 color format: COLOR_FormatYUV420PackedPlanar (equivalent to COLOR_FormatYUV420Planar ) or COLOR_FormatYUV420PackedSemiPlanar (equivalent to COLOR_FormatYUV420SemiPlanar ). They are STRONGLY RECOMMENDED to support both.

5.1.7.視訊編解碼器

  • For acceptable quality of web video streaming and video-conference services, device implementations SHOULD use a hardware VP8 codec that meets the requirements .

If device implementations include a video decoder or encoder:

  • [C-1-1] Video codecs MUST support output and input bytebuffer sizes that accommodate the largest feasible compressed and uncompressed frame as dictated by the standard and configuration but also not overallocate.

  • [C-1-2] Video encoders and decoders MUST support YUV420 8:8:8 flexible color formats ( COLOR_FormatYUV420Flexible ) through CodecCapabilities .

  • [C-1-3] Video encoders and decoders MUST support at least one of a planar or semiplanar YUV420 8:8:8 color format: COLOR_FormatYUV420PackedPlanar (equivalent to COLOR_FormatYUV420Planar ) or COLOR_FormatYUV420PackedSemiPlanar (equivalent to COLOR_FormatYUV420SemiPlanar ). They are STRONGLY RECOMMENDED to support both.

  • [SR] Video encoders and decoders are STRONGLY RECOMMENDED to support at least one of a hardware optimized planar or semiplanar YUV420 8:8:8 color format (YV12, NV12, NV21 or equivalent vendor optimized format.)

  • [C-1-5] Video decoders that support a high bit-depth format (9+ bits per channel) MUST support outputting an 8-bit equivalent format if requested by the application. This MUST be reflected by supporting an YUV420 8:8:8 color format via android.media.MediaCodecInfo .

If device implementations advertise HDR profile support through Display.HdrCapabilities , they:

  • [C-2-1] MUST support HDR static metadata parsing and handling.

If device implementations advertise intra refresh support through FEATURE_IntraRefresh in the MediaCodecInfo.CodecCapabilities class, they:

  • [C-3-1] MUST support the refresh periods in the range of 10 - 60 frames and accurately operate within 20% of configured refresh period.

Unless the application specifies otherwise using the KEY_COLOR_FORMAT format key, video decoder implementations:

  • [C-4-1] MUST default to the color format optimized for hardware display if configured using Surface output.
  • [C-4-2] MUST default to a YUV420 8:8:8 color format optimized for CPU reading if configured to not use Surface output.

5.1.8。 Video Codecs List

格式/編解碼器細節File Types/Container Formats to be supported
H.263
  • 3GPP (.3gp)
  • MPEG-4(.mp4)
  • Matroska (.mkv, decode only)
H.264 AVC有關詳細信息,請參見第5.2和5.3
  • 3GPP (.3gp)
  • MPEG-4(.mp4)
  • MPEG-2 TS (.ts, not seekable)
  • Matroska (.mkv, decode only)
H.265 HEVC有關詳細信息,請參見第5.3節
  • MPEG-4(.mp4)
  • Matroska (.mkv, decode only)
MPEG-2主要簡介
  • MPEG2-TS (.ts, not seekable)
  • MPEG-4 (.mp4, decode only)
  • Matroska (.mkv, decode only)
MPEG-4 sp
  • 3GPP (.3gp)
  • MPEG-4(.mp4)
  • Matroska (.mkv, decode only)
VP8有關詳細信息,請參見第5.2和5.3
VP9有關詳細信息,請參見第5.3節

5.1.9. Media Codec Security

Device implementations MUST ensure compliance with media codec security features as described below.

Android includes support for OMX, a cross-platform multimedia acceleration API, as well as Codec 2.0, a low-overhead multimedia acceleration API.

If device implementations support multimedia, they:

  • [C-1-1] MUST provide support for media codecs either via OMX or Codec 2.0 APIs (or both) as in the Android Open Source Project and not disable or circumvent the security protections. This specifically does not mean that every codec MUST use either the OMX or Codec 2.0 API, only that support for at least one of these APIs MUST be available, and support for the available APIs MUST include the security protections present.
  • [C-SR] Are STRONGLY RECOMMENDED to include support for Codec 2.0 API.

If device implementations do not support the Codec 2.0 API, they:

  • [C-2-1] MUST include the corresponding OMX software codec from the Android Open Source Project (if it is available) for each media format and type (encoder or decoder) supported by the device.
  • [C-2-2] Codecs that have names starting with "OMX.google." MUST be based on their Android Open Source Project source code.
  • [C-SR] Are STRONGLY RECOMMENDED that the OMX software codecs run in a codec process that does not have access to hardware drivers other than memory mappers.

If device implementations support Codec 2.0 API, they:

  • [C-3-1] MUST include the corresponding Codec 2.0 software codec from the Android Open Source Project (if it is available) for each media format and type (encoder or decoder) supported by the device.
  • [C-3-2] MUST house the Codec 2.0 software codecs in the software codec process as provided in the Android Open Source Project to make it possible to more narrowly grant access to software codecs.
  • [C-3-3] Codecs that have names starting with "c2.android." MUST be based on their Android Open Source Project source code.

5.1.10. Media Codec Characterization

If device implementations support media codecs, they:

  • [C-1-1] MUST return correct values of media codec characterization via the MediaCodecInfo API.

尤其:

  • [C-1-2] Codecs with names starting with "OMX." MUST use the OMX APIs and have names that conform to OMX IL naming guidelines.
  • [C-1-3] Codecs with names starting with "c2." MUST use the Codec 2.0 API and have names that conform to Codec 2.0 naming guidelines for Android.
  • [C-1-4] Codecs with names starting with "OMX.google." or "c2.android." MUST NOT be characterized as vendor or as hardware-accelerated.
  • [C-1-5] Codecs that run in a codec process (vendor or system) that have access to hardware drivers other than memory allocators and mappers MUST NOT be characterized as software-only.
  • [C-1-6] Codecs not present in the Android Open Source Project or not based on the source code in that project MUST be characterized as vendor.
  • [C-1-7] Codecs that utilize hardware acceleration MUST be characterized as hardware accelerated.
  • [C-1-8] Codec names MUST NOT be misleading. For example, codecs named "decoders" MUST support decoding, and those named "encoders" MUST support encoding. Codecs with names containing media formats MUST support those formats.

If device implementations support video codecs:

  • [C-2-1] All video codecs MUST publish achievable frame rate data for the following sizes if supported by the codec:
SD (low quality) SD (high quality)高清720p高清1080p超高畫質
視訊解析度
  • 176 x 144 px (H263, MPEG2, MPEG4)
  • 352 x 288 px (MPEG4 encoder, H263, MPEG2)
  • 320 x 180 px (VP8, VP8)
  • 320 x 240 px (other)
  • 704 x 576 px (H263)
  • 640 x 360 px (VP8, VP9)
  • 640 x 480 px (MPEG4 encoder)
  • 720 x 480 px (other)
  • 1408 x 1152 px (H263)
  • 1280 x 720 px (other)
1920 x 1080 px (other than MPEG4) 3840 x 2160 px (HEVC, VP9)
  • [C-2-2] Video codecs that are characterized as hardware accelerated MUST publish performance points information. They MUST each list all supported standard performance points (listed in PerformancePoint API), unless they are covered by another supported standard performance point.
  • Additionally they SHOULD publish extended performance points if they support sustained video performance other than one of the standard ones listed.

5.2.視訊編碼

If device implementations support any video encoder and make it available to third-party apps, they:

  • SHOULD NOT be, over two sliding windows, more than 15% over the bitrate between intraframe (I-frame) intervals.
  • SHOULD NOT be more than 100% over the bitrate over a sliding window of 1 second.

If device implementations include an embedded screen display with the diagonal length of at least 2.5 inches or include a video output port or declare the support of a camera via the android.hardware.camera.any feature flag, they:

  • [C-1-1] MUST include the support of at least one of the VP8 or H.264 video encoders, and make it available for third-party applications.
  • SHOULD support both VP8 and H.264 video encoders, and make it available for third-party applications.

If device implementations support any of the H.264, VP8, VP9 or HEVC video encoders and make it available to third-party applications, they:

  • [C-2-1] MUST support dynamically configurable bitrates.
  • 應支援可變幀速率,在此,視訊編碼器應根據輸入緩衝區的時間戳確定瞬時幀持續時間,並根據該框架持續時間分配其位元儲存桶。

If device implementations support the MPEG-4 SP video encoder and make it available to third-party apps, they:

  • SHOULD support dynamically configurable bitrates for the supported encoder.

If device implementations provide hardware accelerated video or image encoders, and support one or more attached or pluggable hardware camera(s) exposed through the android.camera APIs:

  • [C-4-1] all hardware accelerated video and image encoders MUST support encoding frames from the hardware camera(s).
  • SHOULD support encoding frames from the hardware camera(s) through all video or image encoders.

5.2.1. H.263

If device implementations support H.263 encoders and make it available to third-party apps, they:

  • [C-1-1] MUST support Baseline Profile Level 45.
  • SHOULD support dynamically configurable bitrates for the supported encoder.

5.2.2. H.264

If device implementations support H.264 codec, they:

  • [C-1-1] MUST support Baseline Profile Level 3. However, support for ASO (Arbitrary Slice Ordering), FMO (Flexible Macroblock Ordering) and RS (Redundant Slices) is OPTIONAL.此外,為了維持與其他Android設備的兼容性,建議不要用編碼器將ASO,FMO和RS用於基線設定檔。
  • [C-1-2] MUST support the SD (Standard Definition) video encoding profiles in the following table.
  • 應該支援主要概況等級4。
  • 如下表所示,應支援HD(高清)視訊編碼設定檔。

If device implementations report support of H.264 encoding for 720p or 1080p resolution videos through the media APIs, they:

  • [C-2-1] MUST support the encoding profiles in the following table.
SD(低品質) SD(高品質)高清720p高清1080p
視訊解析度320 x 240 PX 720 x 480 PX 1280 x 720 PX 1920 x 1080 PX
視訊幀率20 幀/秒30 幀/秒30 幀/秒30 幀/秒
視訊比特率384 kbps 2 Mbps 4 Mbps 10Mbps

5.2.3. VP8

If device implementations support VP8 codec, they:

  • [C-1-1] MUST support the SD video encoding profiles.
  • SHOULD support the following HD (High Definition) video encoding profiles.
  • [C-1-2] MUST support writing Matroska WebM files.
  • SHOULD provide a hardware VP8 codec that meets the WebM project RTC hardware coding requirements , to ensure acceptable quality of web video streaming and video-conference services.

If device implementations report support of VP8 encoding for 720p or 1080p resolution videos through the media APIs, they:

  • [C-2-1] MUST support the encoding profiles in the following table.
SD(低品質) SD(高品質)高清720p高清1080p
視訊解析度320 x 180 PX 640 x 360 PX 1280 x 720 PX 1920 x 1080 PX
視訊幀率30 幀/秒30 幀/秒30 幀/秒30 幀/秒
視訊比特率800 kbps 2 Mbps 4 Mbps 10Mbps

5.2.4. VP9

If device implementations support VP9 codec, they:

  • [C-1-2] MUST support Profile 0 Level 3.
  • [C-1-1] MUST support writing Matroska WebM files.
  • [C-1-3] MUST generate CodecPrivate data.
  • 應如下表所示支援HD解碼曲線。
  • [SR] are STRONGLY RECOMMENDED to support the HD decoding profiles as indicated in the following table if there is a hardware encoder.
標清高清720p高清1080p超高畫質
視訊解析度720 x 480 PX 1280 x 720 PX 1920 x 1080 PX 3840 x 2160 PX
視訊幀率30 幀/秒30 幀/秒30 幀/秒30 幀/秒
視訊比特率1.6 Mbps 4 Mbps 5Mbps 20Mbps

If device implementations claim to support Profile 2 or Profile 3 through the Media APIs:

  • Support for 12-bit format is OPTIONAL.

5.2.5。 H.265

If device implementations support H.265 codec, they:

  • [C-1-1] MUST support Main Profile Level 3.
  • SHOULD support the HD encoding profiles as indicated in the following table.
  • [SR] are STRONGLY RECOMMENDED to support the HD encoding profiles as indicated in the following table if there is a hardware encoder.
標清高清720p高清1080p超高畫質
視訊解析度720 x 480 PX 1280 x 720 PX 1920 x 1080 PX 3840 x 2160 PX
視訊幀率30 幀/秒30 幀/秒30 幀/秒30 幀/秒
視訊比特率1.6 Mbps 4 Mbps 5Mbps 20Mbps

5.3.視訊解碼

If device implementations support VP8, VP9, H.264, or H.265 codecs, they:

  • [C-1-1] MUST support dynamic video resolution and frame rate switching through the standard Android APIs within the same stream for all VP8, VP9, H.264, and H.265 codecs in real time and up to the maximum resolution supported by each codec on the device.

5.3.1. MPEG-2

If device implementations support MPEG-2 decoders, they:

  • [C-1-1] MUST support the Main Profile High Level.

5.3.2. H.263

If device implementations support H.263 decoders, they:

  • [C-1-1] MUST support Baseline Profile Level 30 and Level 45.

5.3.3. MPEG-4

If device implementations with MPEG-4 decoders, they:

  • [C-1-1] MUST support Simple Profile Level 3.

5.3.4. H.264

If device implementations support H.264 decoders, they:

  • [C-1-1] MUST support Main Profile Level 3.1 and Baseline Profile.支援ASO(任意切片排序),FMO(靈活的宏觀嵌入訂購)和RS(冗餘切片)是可選的。
  • [C-1-2] MUST be capable of decoding videos with the SD (Standard Definition) profiles listed in the following table and encoded with the Baseline Profile and Main Profile Level 3.1 (including 720p30).
  • 如下表所示,應能使用HD(高清)設定檔來解碼影片。

If the height that is reported by the Display.getSupportedModes() method is equal or greater than the video resolution, device implementations:

  • [C-2-1] MUST support the HD 720p video decoding profiles in the following table.
  • [C-2-2] MUST support the HD 1080p video decoding profiles in the following table.
SD(低品質) SD(高品質)高清720p高清1080p
視訊解析度320 x 240 PX 720 x 480 PX 1280 x 720 PX 1920 x 1080 PX
視訊幀率30 幀/秒30 幀/秒60 fps 30 fps (60 fps Television )
視訊比特率800 kbps 2 Mbps 8 Mbps 20Mbps

5.3.5。 H.265 (HEVC)

If device implementations support H.265 codec, they:

  • [C-1-1] MUST support the Main Profile Level 3 Main tier and the SD video decoding profiles as indicated in the following table.
  • 應如下表所示支援HD解碼曲線。
  • [C-1-2] MUST support the HD decoding profiles as indicated in the following table if there is a hardware decoder.

If the height that is reported by the Display.getSupportedModes() method is equal to or greater than the video resolution, then:

  • [C-2-1] Device implementations MUST support at least one of H.265 or VP9 decoding of 720, 1080 and UHD profiles.
SD(低品質) SD(高品質)高清720p高清1080p超高畫質
視訊解析度352 x 288 PX 720 x 480 PX 1280 x 720 PX 1920 x 1080 PX 3840 x 2160 PX
視訊幀率30 幀/秒30 幀/秒30 幀/秒30/60 fps (60 fps Television with H.265 hardware decoding ) 60 fps
視訊比特率600 kbps 1.6 Mbps 4 Mbps 5Mbps 20Mbps

If device implementations claim to support an HDR Profile ( HEVCProfileMain10HDR10 , HEVCProfileMain10HDR10Plus ) through the Media APIs:

  • [C-3-1] Device implementations MUST accept the required HDR metadata ( MediaFormat#KEY_HDR_STATIC_INFO for all HDR profiles) from the application using MediaCodec API, as well as support extracting the required HDR metadata ( MediaFormat#KEY_HDR_STATIC_INFO for all HDR profiles, as well as MediaFormat#KEY_HDR10_PLUS_INFO for HDR10Plus profiles) from the bitstream and/or container as defined by the relevant specifications. They MUST also support outputting the required HDR metadata ( MediaFormat#KEY_HDR_STATIC_INFO for all HDR profiles) from the bitstream and/or container as defined by the relevant specifications.

  • [C-SR] The device implementations are STRONGLY RECOMMENDED to support outputting the metadata MediaFormat#KEY_HDR10_PLUS_INFO for HDR10Plus profiles via MediaCodec#getOutputFormat(int) .

  • [C-3-2] Device implementations MUST properly display HDR content for HEVCProfileMain10HDR10 profile on the device screen or on a standard video output port (eg, HDMI).

  • [C-SR] Device implementations are STRONGLY RECOMMENDED to properly display HDR content for HEVCProfileMain10HDR10Plus profile on the device screen or on a standard video output port (eg, HDMI).

5.3.6。 VP8

If device implementations support VP8 codec, they:

  • [C-1-1] MUST support the SD decoding profiles in the following table.
  • SHOULD use a hardware VP8 codec that meets the requirements .
  • 應支援下表中的HD解碼概況。

If the height as reported by the Display.getSupportedModes() method is equal or greater than the video resolution, then:

  • [C-2-1] Device implementations MUST support 720p profiles in the following table.
  • [C-2-2] Device implementations MUST support 1080p profiles in the following table.
SD(低品質) SD(高品質)高清720p高清1080p
視訊解析度320 x 180 PX 640 x 360 PX 1280 x 720 PX 1920 x 1080 PX
視訊幀率30 幀/秒30 幀/秒30 fps (60 fps Television ) 30 (60 fps Television )
視訊比特率800 kbps 2 Mbps 8 Mbps 20Mbps

5.3.7. VP9

If device implementations support VP9 codec, they:

  • [C-1-1] MUST support the SD video decoding profiles as indicated in the following table.
  • 應如下表所示支援HD解碼曲線。

If device implementations support VP9 codec and a hardware decoder:

  • [C-2-1] MUST support the HD decoding profiles as indicated in the following table.

If the height that is reported by the Display.getSupportedModes() method is equal to or greater than the video resolution, then:

  • [C-3-1] Device implementations MUST support at least one of VP9 or H.265 decoding of the 720, 1080 and UHD profiles.
SD(低品質) SD(高品質)高清720p高清1080p超高畫質
視訊解析度320 x 180 PX 640 x 360 PX 1280 x 720 PX 1920 x 1080 PX 3840 x 2160 PX
視訊幀率30 幀/秒30 幀/秒30 幀/秒30 fps (60 fps Television with VP9 hardware decoding ) 60 fps
視訊比特率600 kbps 1.6 Mbps 4 Mbps 5Mbps 20Mbps

If device implementations claim to support VP9Profile2 or VP9Profile3 through the 'CodecProfileLevel' media APIs:

  • Support for 12-bit format is OPTIONAL.

If device implementations claim to support an HDR Profile ( VP9Profile2HDR , VP9Profile2HDR10Plus , VP9Profile3HDR , VP9Profile3HDR10Plus ) through the media APIs:

  • [C-4-1] Device implementations MUST accept the required HDR metadata ( MediaFormat#KEY_HDR_STATIC_INFO for all HDR profiles, as well as parameter MediaCodec#PARAMETER_KEY_HDR10_PLUS_INFO for HDR10Plus profiles) from the application using MediaCodec API, as well as support extracting the required HDR metadata ( MediaFormat#KEY_HDR_STATIC_INFO for all HDR profiles, as well as MediaFormat#KEY_HDR10_PLUS_INFO for HDR10Plus profiles) from the bitstream and/or container as defined by the relevant specifications. They MUST also support outputting the required HDR metadata ( MediaFormat#KEY_HDR_STATIC_INFO for all HDR profiles) from the bitstream and/or container as defined by the relevant specifications.

  • [C-4-2] Device implementations MUST properly display HDR content for VP9Profile2HDR and VP9Profile3HDR profiles on the device screen or on a standard video output port (eg, HDMI).

  • [C-SR] The device implementations are STRONGLY RECOMMENDED to support outputting the metadata MediaFormat#KEY_HDR10_PLUS_INFO for HDR10Plus profiles via MediaCodec#getOutputFormat(int) .

  • [C-SR] Device implementations are STRONGLY RECOMMENDED to properly display HDR content for VP9Profile2HDR10Plus and VP9Profile3HDR10Plus profiles on the device screen or on a standard video output port (eg, HDMI).

5.3.8. Dolby Vision

If device implementations declare support for the Dolby Vision decoder through HDR_TYPE_DOLBY_VISION , they:

  • [C-1-1] MUST provide a Dolby Vision-capable extractor.
  • [C-1-2] MUST properly display Dolby Vision content on the device screen or on a standard video output port (eg, HDMI).
  • [C-1-3] MUST set the track index of backward-compatible base-layer(s) (if present) to be the same as the combined Dolby Vision layer's track index.

5.3.9. AV1

If device implementations support AV1 codec, they:

  • [C-1-1] MUST support Profile 0 including 10-bit content.

5.4.聲音錄製

While some of the requirements outlined in this section are listed as SHOULD since Android 4.3, the Compatibility Definition for future versions are planned to change these to MUST. Existing and new Android devices are STRONGLY RECOMMENDED to meet these requirements that are listed as SHOULD, or they will not be able to attain Android compatibility when upgraded to the future version.

5.4.1. Raw Audio Capture and Microphone Information

If device implementations declare android.hardware.microphone , they:

  • [C-1-1] MUST allow capture of raw audio content with the following characteristics:

    • 格式:線性PCM,16位
    • Sampling rates : 8000, 11025, 16000, 44100, 48000 Hz
    • 頻道:單聲道
  • SHOULD allow capture of raw audio content with the following characteristics:

    • Format : Linear PCM, 16-bit and 24-bit
    • Sampling rates : 8000, 11025, 16000, 22050, 24000, 32000, 44100, 48000 Hz
    • Channels : As many channels as the number of microphones on the device
  • [C-1-2] MUST capture at above sample rates without up-sampling.

  • [C-1-3] MUST include an appropriate anti-aliasing filter when the sample rates given above are captured with down-sampling.
  • SHOULD allow AM radio and DVD quality capture of raw audio content, which means the following characteristics:

    • 格式:線性PCM,16位
    • Sampling rates : 22050, 48000 Hz
    • 頻道:立體聲
  • [C-1-4] MUST honor the MicrophoneInfo API and properly fill in information for the available microphones on device accessible to the third-party applications via the AudioManager.getMicrophones() API, and the currently active microphones which are accessible to the third party applications via the AudioRecord.getActiveMicrophones() and MediaRecorder.getActiveMicrophones() APIs. If device implementations allow AM radio and DVD quality capture of raw audio content, they:

  • [C-2-1] MUST capture without up-sampling at any ratio higher than 16000:22050 or 44100:48000.

  • [C-2-2] MUST include an appropriate anti-aliasing filter for any up-sampling or down-sampling.

5.4.2.語音辨識捕獲

If device implementations declare android.hardware.microphone , they:

  • [C-1-1] MUST capture android.media.MediaRecorder.AudioSource.VOICE_RECOGNITION audio source at one of the sampling rates, 44100 and 48000.
  • [C-1-2] MUST, by default, disable any noise reduction audio processing when recording an audio stream from the AudioSource.VOICE_RECOGNITION audio source.
  • [C-1-3] MUST, by default, disable any automatic gain control when recording an audio stream from the AudioSource.VOICE_RECOGNITION audio source.
  • SHOULD record the voice recognition audio stream with approximately flat amplitude versus frequency characteristics: specifically, ±3 dB, from 100 Hz to 4000 Hz.
  • SHOULD record the voice recognition audio stream with input sensitivity set such that a 90 dB sound power level (SPL) source at 1000 Hz yields RMS of 2500 for 16-bit samples.
  • SHOULD record the voice recognition audio stream so that the PCM amplitude levels linearly track input SPL changes over at least a 30 dB range from -18 dB to +12 dB re 90 dB SPL at the microphone.
  • SHOULD record the voice recognition audio stream with total harmonic distortion (THD) less than 1% for 1 kHz at 90 dB SPL input level at the microphone.

If device implementations declare android.hardware.microphone and noise suppression (reduction) technologies tuned for speech recognition, they:

  • [C-2-1] MUST allow this audio effect to be controllable with the android.media.audiofx.NoiseSuppressor API.
  • [C-2-2] MUST uniquely identify each noise suppression technology implementation via the AudioEffect.Descriptor.uuid field.

5.4.3.捕獲以重新路由播放

android.media.MediaRecorder.AudioSource類別包含REMOTE_SUBMIX音訊來源。

If device implementations declare both android.hardware.audio.output and android.hardware.microphone , they:

  • [C-1-1] MUST properly implement the REMOTE_SUBMIX audio source so that when an application uses the android.media.AudioRecord API to record from this audio source, it captures a mix of all audio streams except for the following:

    • AudioManager.STREAM_RING
    • AudioManager.STREAM_ALARM
    • AudioManager.STREAM_NOTIFICATION

5.4.4. Acoustic Echo Canceler

If device implementations declare android.hardware.microphone , they:

  • SHOULD implement an Acoustic Echo Canceler (AEC) technology tuned for voice communication and applied to the capture path when capturing using AudioSource.VOICE_COMMUNICATION

If device implementations provides an Acoustic Echo Canceler which is inserted in the capture audio path when AudioSource.VOICE_COMMUNICATION is selected, they:

5.4.5。 Concurrent Capture

If device implementations declare android.hardware.microphone ,they MUST implement concurrent capture as described in this document .具體來說:

  • [C-1-1] MUST allow concurrent access to microphone by an accessibility service capturing with AudioSource.VOICE_RECOGNITION and at least one application capturing with any AudioSource .
  • [C-1-2] MUST allow concurrent access to microphone by a pre-installed application that holds an Assistant role and at least one application capturing with any AudioSource except for AudioSource.VOICE_COMMUNICATION or AudioSource.CAMCORDER .
  • [C-1-3] MUST silence the audio capture for any other application, except for an accessibility service, while an application is capturing with AudioSource.VOICE_COMMUNICATION or AudioSource.CAMCORDER . However, when an app is capturing via AudioSource.VOICE_COMMUNICATION then another app can capture the voice call if it is a privileged (pre-installed) app with permission CAPTURE_AUDIO_OUTPUT .
  • [C-1-4] If two or more applications are capturing concurrently and if neither app has an UI on top, the one that started capture the most recently receives audio.

5.4.6。 Microphone Gain Levels

If device implementations declare android.hardware.microphone , they:

  • SHOULD exhibit approximately flat amplitude-versus-frequency characteristics in the mid-frequency range: specifically ±3dB from 100 Hz to 4000 Hz for each and every microphone used to record the voice recognition audio source.
  • SHOULD set audio input sensitivity such that a 1000 Hz sinusoidal tone source played at 90 dB Sound Pressure Level (SPL) yields a response with RMS of 2500 for 16 bit-samples (or -22.35 dB Full Scale for floating point/double precision samples) for each and every microphone used to record the voice recognition audio source.
  • [C-SR] are STRONGLY RECOMMENDED to exhibit amplitude levels in the low frequency range: specifically from ±20 dB from 5 Hz to 100 Hz compared to the mid-frequency range for each and every microphone used to record the voice recognition audio source.
  • [C-SR] are STRONGLY RECOMMENDED to exhibit amplitude levels in the high frequency range: specifically from ±30 dB from 4000 Hz to 22 KHz compared to the mid-frequency range for each and every microphone used to record the voice recognition audio source.

5.5.音訊播放

Android includes the support to allow apps to playback audio through the audio output peripheral as defined in section 7.8.2.

5.5.1.原始音訊播放

If device implementations declare android.hardware.audio.output , they:

  • [C-1-1] MUST allow playback of raw audio content with the following characteristics:

    • Source formats : Linear PCM, 16-bit, 8-bit, float
    • Channels : Mono, Stereo, valid multichannel configurations with up to 8 channels
    • Sampling rates (in Hz) :
      • 8000, 11025, 16000, 22050, 32000, 44100, 48000 at the channel configurations listed above
      • 96000 in mono and stereo
  • SHOULD allow playback of raw audio content with the following characteristics:

    • Sampling rates : 24000

5.5.2.音訊效果

Android為裝置實作提供了音訊效果的API

If device implementations declare the feature android.hardware.audio.output , they:

  • [C-1-1] MUST support the EFFECT_TYPE_EQUALIZER and EFFECT_TYPE_LOUDNESS_ENHANCER implementations controllable through the AudioEffect subclasses Equalizer and LoudnessEnhancer .
  • [C-1-2] MUST support the visualizer API implementation, controllable through the Visualizer class.
  • [C-1-3] MUST support the EFFECT_TYPE_DYNAMICS_PROCESSING implementation controllable through the AudioEffect subclass DynamicsProcessing .
  • SHOULD support the EFFECT_TYPE_BASS_BOOST , EFFECT_TYPE_ENV_REVERB , EFFECT_TYPE_PRESET_REVERB , and EFFECT_TYPE_VIRTUALIZER implementations controllable through the AudioEffect sub-classes BassBoost , EnvironmentalReverb , PresetReverb , and Virtualizer .
  • [C-SR] Are STRONGLY RECOMMENDED to support effects in floating-point and multichannel.

5.5.3.音訊輸出音量

Automotive device implementations:

  • SHOULD allow adjusting audio volume separately per each audio stream using the content type or usage as defined by AudioAttributes and car audio usage as publicly defined in android.car.CarAudioManager .

5.6.音訊延遲

音訊延遲是隨著音訊訊號通過系統的時間延遲。許多類別的應用程式都依賴短延遲來實現即時聲音效果。

出於本節的目的,請使用以下定義:

  • 輸出延遲。當應用程式寫入PCM編碼資料的訊框與將對應的聲音呈現給在裝置感測器處的環境或訊號通過連接埠離開裝置時,可以在外部觀察到裝置時的間隔。
  • 冷輸出潛伏期。當音訊輸出系統閒置並在請求之前降低電源時,第一幀的輸出延遲。
  • 連續輸出延遲。設備播放音訊後,後續幀的輸出延遲。
  • 輸入延遲。環境向設備在設備感測器處提出聲音之間的間隔或透過連接埠進入設備以及應用程式讀取相應的PCM編碼資料幀時的間隔。
  • 輸入遺失。輸入訊號的初始部分是無法使用或不可用的。
  • 冷輸入延遲。遺失的輸入時間和第一幀的輸入延遲的總和,當音訊輸入系統閒置並在請求之前停止電源。
  • 連續輸入延遲。設備擷取音訊時,後續幀的輸入延遲。
  • 冷輸出抖動。冷輸出延遲值的單獨測量值之間的可變性。
  • 冷輸入抖動。冷輸入延遲值單獨測量之間的可變性。
  • 連續的往返潛伏期。連續輸入延遲加連續輸出延遲加一個緩衝區的總和。緩衝區允許應用程式處理應用程式的訊號和時間的時間,以減輕輸入和輸出流之間的相位差異。
  • OpenSL ES PCM緩衝液佇列APIAndroid NDK中的PCM相關的集合OPESL ES API。
  • AAudio native audio API . The set of AAudio APIs within Android NDK .
  • timestamp . A pair consisting of a relative frame position within a stream and the estimated time when that frame enters or leaves the audio processing pipeline on the associated endpoint. See also AudioTimestamp .
  • glitch . A temporary interruption or incorrect sample value in the audio signal, typically caused by a buffer underrun for output, buffer overrun for input, or any other source of digital or analog noise.

If device implementations declare android.hardware.audio.output , they MUST meet or exceed the following requirements:

  • [C-1-1] The output timestamp returned by AudioTrack.getTimestamp and AAudioStream_getTimestamp is accurate to +/- 2 ms.
  • [C-1-2] Cold output latency of 500 milliseconds or less.

If device implementations declare android.hardware.audio.output they are STRONGLY RECOMMENDED to meet or exceed the following requirements:

  • [C-SR] Cold output latency of 100 milliseconds or less. Existing and new devices that run this version of Android are VERY STRONGLY RECOMMENDED to meet these requirements now. In a future platform release in 2021, we will require Cold output latency of 200 ms or less as a MUST.
  • [C-SR] Continuous output latency of 45 milliseconds or less.
  • [C-SR] Minimize the cold output jitter.
  • [C-SR] The output timestamp returned by AudioTrack.getTimestamp and AAudioStream_getTimestamp is accurate to +/- 1 ms.

If device implementations meet the above requirements, after any initial calibration, when using both the OpenSL ES PCM buffer queue and AAudio native audio APIs, for continuous output latency and cold output latency over at least one supported audio output device, they are:

If device implementations do not meet the requirements for low-latency audio via both the OpenSL ES PCM buffer queue and AAudio native audio APIs, they:

  • [C-2-1] MUST NOT report support for low-latency audio.

If device implementations include android.hardware.microphone , they MUST meet these input audio requirements:

  • [C-3-1] Limit the error in input timestamps, as returned by AudioRecord.getTimestamp or AAudioStream_getTimestamp , to +/- 2 ms. "Error" here means the deviation from the correct value.
  • [C-3-2] Cold input latency of 500 milliseconds or less.

If device implementations include android.hardware.microphone , they are STRONGLY RECOMMENDED to meet these input audio requirements:

  • [C-SR] Cold input latency of 100 milliseconds or less. Existing and new devices that run this version of Android are VERY STRONGLY RECOMMENDED to meet these requirements now. In a future platform release in 2021 we will require Cold input latency of 200 ms or less as a MUST.
  • [C-SR] Continuous input latency of 30 milliseconds or less.
  • [C-SR] Continuous round-trip latency of 50 milliseconds or less.
  • [C-SR] Minimize the cold input jitter.
  • [C-SR] Limit the error in input timestamps, as returned by AudioRecord.getTimestamp or AAudioStream_getTimestamp , to +/- 1 ms.

5.7.網路協定

Device implementations MUST support the media network protocols for audio and video playback as specified in the Android SDK documentation.

If device implementations include an audio or a video decoder, they:

  • [C-1-1] MUST support all required codecs and container formats in section 5.1 over HTTP(S).

  • [C-1-2] MUST support the media segment formats shown in the Media Segment Formats table below over HTTP Live Streaming draft protocol, Version 7 .

  • [C-1-3] MUST support the following RTP audio video profile and related codecs in the RTSP table below.例外,請參閱第5.1節的腳註。

Media Segment Formats

細分格式參考)所需的編解碼器支持
MPEG-2傳輸流ISO 13818視訊編解碼器:
  • H264 AVC
  • MPEG-4 sp
  • MPEG-2
有關H264 AVC,MPEG2-4 SP的詳細信息,請參見第5.1.3節
和MPEG-2。

音訊編解碼器:

  • 亞克力
有關AAC及其變體的詳細信息,請參見第5.1.1節
帶有ADT框架和ID3標籤的AAC ISO 13818-7有關AAC及其變體的詳細信息,請參見第5.1.1節
網路VTT網路VTT

RTSP(RTP,SDP)

個人資料名稱參考)所需的編解碼器支持
H264 AVC RFC 6184有關H264 AVC的詳細信息,請參見第5.1.3節
mp4a-latm RFC 6416有關AAC及其變體的詳細信息,請參見第5.1.1節
H263-1998 RFC 3551
RFC 4629
RFC 2190
有關H263的詳細信息,請參見第5.1.3節
H263-2000 RFC 4629有關H263的詳細信息,請參見第5.1.3節
抗微生物藥物抗藥性RFC 4867有關AMR-NB的詳細信息,請參見第5.1.1節
AMR-WB RFC 4867有關AMR-WB的詳細信息,請參見第5.1.1節
mp4v-es RFC 6416有關MPEG-4 SP的詳細信息,請參見第5.1.3節
MPEG4生成RFC 3640有關AAC及其變體的詳細信息,請參見第5.1.1節
MP2T RFC 2250有關詳細信息

5.8.安全媒體

If device implementations support secure video output and are capable of supporting secure surfaces, they:

  • [C-1-1] MUST declare support for Display.FLAG_SECURE .

If device implementations declare support for Display.FLAG_SECURE and support wireless display protocol, they:

  • [C-2-1] MUST secure the link with a cryptographically strong mechanism such as HDCP 2.x or higher for the displays connected through wireless protocols such as Miracast.

If device implementations declare support for Display.FLAG_SECURE and support wired external display, they:

  • [C-3-1] MUST support HDCP 1.2 or higher for all external displays connected via a user-accessible wired port.

5.9.樂器數位介面 (MIDI)

If device implementations report support for feature android.software.midi via the android.content.pm.PackageManager class, they:

  • [C-1-1] MUST support MIDI over all MIDI-capable hardware transports for which they provide generic non-MIDI connectivity, where such transports are:

  • [C-1-2] MUST support the inter-app MIDI software transport (virtual MIDI devices)

  • [C-1-3] MUST include libamidi.so (native MIDI support)

5.10.專業音響

If device implementations report support for feature android.hardware.audio.pro via the android.content.pm.PackageManager class, they:

  • [C-1-1] MUST report support for feature android.hardware.audio.low_latency .
  • [C-1-2] MUST have a continuous round-trip audio latency, as defined in section 5.6 Audio Latency , of 20 milliseconds or less and SHOULD be 10 milliseconds or less over at least one supported path.
  • [C-1-3] MUST include a USB port(s) supporting USB host mode and USB peripheral mode.
  • [C-1-4] MUST report support for feature android.software.midi .
  • [C-1-5] MUST meet latencies and USB audio requirements using both the OpenSL ES PCM buffer queue API and at least one path of the AAudio native audio API.
  • [SR] Are STRONGLY RECOMMENDED to meet latencies and USB audio requirements using the AAudio native audio API over the MMAP path .
  • [C-1-6] MUST have Cold output latency of 200 milliseconds or less.
  • [C-1-7] MUST have Cold input latency of 200 milliseconds or less.
  • [SR] Are STRONGLY RECOMMENDED to provide a consistent level of CPU performance while audio is active and CPU load is varying. This SHOULD be tested using the Android app version of SynthMark commit id 09b13c6f49ea089f8c31e5d035f912cc405b7ab8 . SynthMark uses a software synthesizer running on a simulated audio framework that measures system performance. The SynthMark app needs to be run using the “Automated Test” option and achieve the following results:
    • voicemark.90 >= 32 voices
    • latencymark.fixed.little <= 15 msec
    • latencymark.dynamic.little <= 50 msec

See the SynthMark documentation for an explanation of the benchmarks.

  • SHOULD minimize audio clock inaccuracy and drift relative to standard time.
  • SHOULD minimize audio clock drift relative to the CPU CLOCK_MONOTONIC when both are active.
  • SHOULD minimize audio latency over on-device transducers.
  • SHOULD minimize audio latency over USB digital audio.
  • SHOULD document audio latency measurements over all paths.
  • SHOULD minimize jitter in audio buffer completion callback entry times, as this affects usable percentage of full CPU bandwidth by the callback.
  • SHOULD provide zero audio glitches under normal use at reported latency.
  • SHOULD provide zero inter-channel latency difference.
  • SHOULD minimize MIDI mean latency over all transports.
  • SHOULD minimize MIDI latency variability under load (jitter) over all transports.
  • SHOULD provide accurate MIDI timestamps over all transports.
  • SHOULD minimize audio signal noise over on-device transducers, including the period immediately after cold start.
  • SHOULD provide zero audio clock difference between the input and output sides of corresponding end-points, when both are active.相應的終點的範例包括在裝置上的麥克風和揚聲器,或音訊插孔輸入和輸出。
  • SHOULD handle audio buffer completion callbacks for the input and output sides of corresponding end-points on the same thread when both are active, and enter the output callback immediately after the return from the input callback.或者,如果在同一線程上處理回調是不可行的,請在輸入輸入回調後不久輸入輸出回調以允許應用程式具有輸入和輸出側的一致時機。
  • SHOULD minimize the phase difference between HAL audio buffering for the input and output sides of corresponding end-points.
  • SHOULD minimize touch latency.
  • SHOULD minimize touch latency variability under load (jitter).
  • SHOULD have a latency from touch input to audio output of less than or equal to 40 ms.

If device implementations meet all of the above requirements, they:

If device implementations include a 4 conductor 3.5mm audio jack, they:

If device implementations omit a 4 conductor 3.5mm audio jack and include a USB port(s) supporting USB host mode, they:

  • [C-3-1] MUST implement the USB audio class.
  • [C-3-2] MUST have a continuous round-trip audio latency of 20 milliseconds or less over the USB host mode port using USB audio class.
  • The continuous round-trip audio latency SHOULD be 10 milliseconds or less over the USB host mode port using USB audio class.
  • [C-SR] Are STRONGLY RECOMMENDED to support simultaneous I/O up to 8 channels each direction, 96 kHz sample rate, and 24-bit or 32-bit depth, when used with USB audio peripherals that also support these requirements.

If device implementations include an HDMI port, they:

  • SHOULD support output in stereo and eight channels at 20-bit or 24-bit depth and 192 kHz without bit-depth loss or resampling, in at least one configuration.

5.11.捕獲未處理的

Android includes support for recording of unprocessed audio via the android.media.MediaRecorder.AudioSource.UNPROCESSED audio source.在OpenSL ES中,可以使用記錄預設SL_ANDROID_RECORDING_PRESET_UNPROCESSED來存取它。

If device implementations intent to support unprocessed audio source and make it available to third-party apps, they:

  • [C-1-1] MUST report the support through the android.media.AudioManager property PROPERTY_SUPPORT_AUDIO_SOURCE_UNPROCESSED .

  • [C-1-2] MUST exhibit approximately flat amplitude-versus-frequency characteristics in the mid-frequency range: specifically ±10dB from 100 Hz to 7000 Hz for each and every microphone used to record the unprocessed audio source.

  • [C-1-3] MUST exhibit amplitude levels in the low frequency range: specifically from ±20 dB from 5 Hz to 100 Hz compared to the mid-frequency range for each and every microphone used to record the unprocessed audio source.

  • [C-1-4] MUST exhibit amplitude levels in the high frequency range: specifically from ±30 dB from 7000 Hz to 22 KHz compared to the mid-frequency range for each and every microphone used to record the unprocessed audio source.

  • [C-1-5] MUST set audio input sensitivity such that a 1000 Hz sinusoidal tone source played at 94 dB Sound Pressure Level (SPL) yields a response with RMS of 520 for 16 bit-samples (or -36 dB Full Scale for floating point/double precision samples) for each and every microphone used to record the unprocessed audio source.

  • [C-1-6] MUST have a signal-to-noise ratio (SNR) at 60 dB or higher for each and every microphone used to record the unprocessed audio source. (whereas the SNR is measured as the difference between 94 dB SPL and equivalent SPL of self noise, A-weighted).

  • [C-1-7] MUST have a total harmonic distortion (THD) less than be less than 1% for 1 kHZ at 90 dB SPL input level at each and every microphone used to record the unprocessed audio source.

  • MUST not have any other signal processing (eg Automatic Gain Control, High Pass Filter, or Echo cancellation) in the path other than a level multiplier to bring the level to desired range.換句話說:

  • [C-1-8] If any signal processing is present in the architecture for any reason, it MUST be disabled and effectively introduce zero delay or extra latency to the signal path.
  • [C-1-9] The level multiplier, while allowed to be on the path, MUST NOT introduce delay or latency to the signal path.

所有SPL測量值直接在正在測試的麥克風旁邊進行。對於多個麥克風配置,這些要求適用於每個麥克風。

If device implementations declare android.hardware.microphone but do not support unprocessed audio source, they:

  • [C-2-1] MUST return null for the AudioManager.getProperty(PROPERTY_SUPPORT_AUDIO_SOURCE_UNPROCESSED) API method, to properly indicate the lack of support.
  • [SR] are still STRONGLY RECOMMENDED to satisfy as many of the requirements for the signal path for the unprocessed recording source.

6. 開發者工具和選項相容性

6.1.開發者工具

設備實現:

  • [C-0-1] MUST support the Android Developer Tools provided in the Android SDK.
  • Android Debug Bridge(ADB)

    • [C-0-2] MUST support adb as documented in the Android SDK and the shell commands provided in the AOSP, which can be used by app developers, including dumpsys cmd stats
    • [C-SR] Are STRONGLY RECOMMENDED to support the shell command cmd testharness .
    • [C-0-3] MUST NOT alter the format or the contents of device system events (batterystats , diskstats, fingerprint, graphicsstats, netstats, notification, procstats) logged via the dumpsys command.
    • [C-0-10] MUST record, without omission, and make the following events accessible and available to the cmd stats shell command and the StatsManager System API class.
      • ActivityForegroundStateChanged
      • AnomalyDetected
      • AppBreadcrumbReported
      • 應用程式發生崩潰
      • 應用程式啟動發生
      • BatteryLevelChanged
      • BatterySaverModeStateChanged
      • BleScanResultReceived
      • BleScanStateChanged
      • ChargingStateChanged
      • DeviceIdleModeStateChanged
      • ForegroundServiceStateChanged
      • GpsScanStateChanged
      • JobStateChanged
      • 插入狀態改變
      • ScheduledJobStateChanged
      • 螢幕狀態改變
      • SyncStateChanged
      • SystemElapsedRealtime
      • UidProcessStateChanged
      • 喚醒鎖定狀態更改
      • 發生喚醒警報
      • WifiLockStateChanged
      • WifiMulticastLockStateChanged
      • WifiScanStateChanged
    • [C-0-4] MUST have the device-side adb daemon be inactive by default and there MUST be a user-accessible mechanism to turn on the Android Debug Bridge.
    • [C-0-5] MUST support secure adb. Android包含安全ADB的支援。安全ADB可以在已知身份驗證的宿主上啟用ADB。
    • [C-0-6] MUST provide a mechanism allowing adb to be connected from a host machine.例如:

      • Device implementations without a USB port supporting peripheral mode MUST implement adb via local-area network (such as Ethernet or Wi-Fi).
      • MUST provide drivers for Windows 7, 9 and 10, allowing developers to connect to the device using the adb protocol.
  • Dalvik調試監視器服務(DDMS)

    • [C-0-7] MUST support all ddms features as documented in the Android SDK.由於DDMS使用ADB,因此預設情況下,對DDMS的支援應無效,但每當使用者啟動Android Debug Bridge(如上所述)時,必須支援DDMS。
    • [C-0-8] MUST include the Monkey framework and make it available for applications to use.
  • Systrace
    • [C-0-9] MUST support the systrace tool as documented in the Android SDK. Systrace MUST be inactive by default and there MUST be a user-accessible mechanism to turn on Systrace.
  • 完美

    • [C-SR] Are STRONGLY RECOMMENDED to expose a /system/bin/perfetto binary to the shell user which cmdline complies with the perfetto documentation .
    • [C-SR] The perfetto binary is STRONGLY RECOMMENDED to accept as input a protobuf config that complies with the schema defined in the perfetto documentation .
    • [C-SR] The perfetto binary is STRONGLY RECOMMENDED to write as output a protobuf trace that complies with the schema defined in the perfetto documentation .
    • [C-SR] Are STRONGLY RECOMMENDED to provide, through the perfetto binary, at least the data sources described in the perfetto documentation .
  • Test Harness Mode

    If device implementations support the shell command cmd testharness and run cmd testharness enable , they:

    • [C-2-1] MUST return true for ActivityManager.isRunningInUserTestHarness()
    • [C-2-2] MUST implement Test Harness Mode as described in harness mode documentation .

If device implementations report the support of Vulkan 1.0 or higher via the android.hardware.vulkan.version feature flags, they:

  • [C-1-1] MUST provide an affordance for the app developer to enable/disable GPU debug layers.
  • [C-1-2] MUST, when the GPU debug layers are enabled, enumerate layers in libraries provided by external tools (ie not part of the platform or application package) found in debuggable applications' base directory to support vkEnumerateInstanceLayerProperties() and vkCreateInstance() API methods.

6.2.開發者選項

Android包括對開發人員配置與應用程式開發相關的設定的支援。

Device implementations MUST provide a consistent experience for Developer Options, they:

  • [C-0-1] MUST honor the android.settings.APPLICATION_DEVELOPMENT_SETTINGS intent to show application development-related settings. The upstream Android implementation hides the Developer Options menu by default and enables users to launch Developer Options after pressing seven (7) times on the Settings > About Device > Build Number menu item.
  • [C-0-2] MUST hide Developer Options by default.
  • [C-0-3] MUST provide a clear mechanism that does not give preferential treatment to one third-party app as opposed to another to enable Developer Options. MUST provide a public visible document or website that describes how to enable Developer Options. This document or website MUST be linkable from the Android SDK documents.
  • SHOULD have an ongoing visual notification to the user when Developer Options is enabled and the safety of the user is of concern.
  • MAY temporarily limit access to the Developer Options menu, by visually hiding or disabling the menu, to prevent distraction for scenarios where the safety of the user is of concern.

7. 硬體相容性

If a device includes a particular hardware component that has a corresponding API for third-party developers:

  • [C-0-1] The device implementation MUST implement that API as described in the Android SDK documentation.

如果SDK中的API與指定為選購的硬體元件相互作用,且設備實作不具備該元件:

  • [C-0-2] Complete class definitions (as documented by the SDK) for the component APIs MUST still be presented.
  • [C-0-3] The API's behaviors MUST be implemented as no-ops in some reasonable fashion.
  • [C-0-4] API methods MUST return null values where permitted by the SDK documentation.
  • [C-0-5] API methods MUST return no-op implementations of classes where null values are not permitted by the SDK documentation.
  • [C-0-6] API methods MUST NOT throw exceptions not documented by the SDK documentation.
  • [C-0-7] Device implementations MUST consistently report accurate hardware configuration information via the getSystemAvailableFeatures() and hasSystemFeature(String) methods on the android.content.pm.PackageManager class for the same build fingerprint.

A typical example of a scenario where these requirements apply is the telephony API: Even on non-phone devices, these APIs MUST be implemented as reasonable no-ops.

7.1.顯示和圖形

Android包括適當地調整應用程式資產和UI佈局的設施,以確保第三方應用程式在各種硬體配置上運作良好。 On the Android-compatible display(s) where all third-party Android-compatible applications can run, device implementations MUST properly implement these APIs and behaviors, as detailed in this section.

本節中要求所引用的單位定義如下:

  • 物理對角線。在顯示器照明部分的兩個相對角之間的距離為英吋。
  • 每吋點(DPI) 。由線性水平或垂直跨度為1英吋的像素的數量。 Where dpi values are listed, both horizontal and vertical dpi MUST fall within the range.
  • 縱橫比。較長尺寸的像素與螢幕較短維的比例。例如,480x854像素的顯示為854/480 = 1.779,或大致為「 16:9」。
  • 密度無關的像素(DP) 。虛擬像素單元歸一化為160 dpi螢幕,計算為:像素= dps *(密度/160)。

7.1.1.螢幕配置

7.1.1.1. Screen Size and Shape

The Android UI framework supports a variety of different logical screen layout sizes, and allows applications to query the current configuration's screen layout size via Configuration.screenLayout with the SCREENLAYOUT_SIZE_MASK and Configuration.smallestScreenWidthDp .

設備實現:

  • [C-0-1] MUST report the correct layout size for the Configuration.screenLayout as defined in the Android SDK documentation. Specifically, device implementations MUST report the correct logical density-independent pixel (dp) screen dimensions as below:

    • Devices with the Configuration.uiMode set as any value other than UI_MODE_TYPE_WATCH, and reporting a small size for the Configuration.screenLayout , MUST have at least 426 dp x 320 dp.
    • Devices reporting a normal size for the Configuration.screenLayout , MUST have at least 480 dp x 320 dp.
    • Devices reporting a large size for the Configuration.screenLayout , MUST have at least 640 dp x 480 dp.
    • Devices reporting a xlarge size for the Configuration.screenLayout , MUST have at least 960 dp x 720 dp.
  • [C-0-2] MUST correctly honor applications' stated support for screen sizes through the < supports-screens > attribute in the AndroidManifest.xml, as described in the Android SDK documentation.

  • MAY have the Android-compatible display(s) with rounded corners.

If device implementations support UI_MODE_TYPE_NORMAL and include the Android-compatible display(s) with rounded corners, they:

  • [C-1-1] MUST ensure that the radius of the rounded corners is less than or equal to 38 dp.
  • SHOULD include user affordance to switch to the display mode with the rectangular corners.
7.1.1.2.螢幕縱橫比

While there is no restriction to the aspect ratio of the physical display for the Android-compatible display(s), the aspect ratio of the logical display where third-party apps are rendered, which can be derived from the height and width values reported through the view.Display APIs and Configuration APIs, MUST meet the following requirements:

  • [C-0-1] Device implementations with Configuration.uiMode set to UI_MODE_TYPE_NORMAL MUST have an aspect ratio value less than or equal to 1.86 (roughly 16:9), unless the app meets one of the following conditions:

  • [C-0-2] Device implementations with Configuration.uiMode set to UI_MODE_TYPE_NORMAL MUST have an aspect ratio value equal to or greater than 1.3333 (4:3), unless the app can be stretched wider by meeting one of the following conditions:

  • [C-0-3] Device implementations with the Configuration.uiMode set as UI_MODE_TYPE_WATCH MUST have an aspect ratio value set as 1.0 (1:1).

7.1.1.3。螢幕密度

The Android UI framework defines a set of standard logical densities to help application developers target application resources.

  • [C-0-1] By default, device implementations MUST report only one of the Android framework densities that are listed on DisplayMetrics through the DENSITY_DEVICE_STABLE API and this value MUST NOT change at any time; however, the device MAY report a different arbitrary density according to the display configuration changes made by the user (for example, display size) set after initial boot.

  • Device implementations SHOULD define the standard Android framework density that is numerically closest to the physical density of the screen, unless that logical density pushes the reported screen size below the minimum supported. If the standard Android framework density that is numerically closest to the physical density results in a screen size that is smaller than the smallest supported compatible screen size (320 dp width), device implementations SHOULD report the next lowest standard Android framework density.

If there is an affordance to change the display size of the device:

  • [C-1-1] The display size MUST NOT be scaled any larger than 1.5 times the native density or produce an effective minimum screen dimension smaller than 320dp (equivalent to resource qualifier sw320dp), whichever comes first.
  • [C-1-2] Display size MUST NOT be scaled any smaller than 0.85 times the native density.
  • To ensure good usability and consistent font sizes, it is RECOMMENDED that the following scaling of Native Display options be provided (while complying with the limits specified above)
  • Small: 0.85x
  • Default: 1x (Native display scale)
  • Large: 1.15x
  • Larger: 1.3x
  • Largest 1.45x

7.1.2.顯示指標

If device implementations include the Android-compatible display(s) or video output to the Android-compatible display screen(s), they:

If device implementations does not include an embedded screen or video output, they:

  • [C-2-1] MUST report correct values of the Android-compatible display as defined in the android.util.DisplayMetrics API for the emulated default view.Display .

7.1.3.螢幕方向

設備實現:

  • [C-0-1] MUST report which screen orientations they support ( android.hardware.screen.portrait and/or android.hardware.screen.landscape ) and MUST report at least one supported orientation. For example, a device with a fixed orientation landscape screen, such as a television or laptop, SHOULD only report android.hardware.screen.landscape .
  • [C-0-2] MUST report the correct value for the device's current orientation, whenever queried via the android.content.res.Configuration.orientation , android.view.Display.getOrientation() , or other APIs.

If device implementations support both screen orientations, they:

  • [C-1-1] MUST support dynamic orientation by applications to either portrait or landscape screen orientation. That is, the device MUST respect the application's request for a specific screen orientation.
  • [C-1-2] MUST NOT change the reported screen size or density when changing orientation.
  • MAY select either portrait or landscape orientation as the default.

7.1.4. 2D 和 3D 圖形加速

7.1.4.1 OpenGL ES

設備實現:

  • [C-0-1] MUST correctly identify the supported OpenGL ES versions (1.1, 2.0, 3.0, 3.1, 3.2) through the managed APIs (such as via the GLES10.getString() method) and the native APIs.
  • [C-0-2] MUST include the support for all the corresponding managed APIs and native APIs for every OpenGL ES versions they identified to support.

If device implementations include a screen or video output, they:

  • [C-1-1] MUST support both OpenGL ES 1.1 and 2.0, as embodied and detailed in the Android SDK documentation .
  • [C-SR] Are STRONGLY RECOMMENDED to support OpenGL ES 3.1.
  • SHOULD support OpenGL ES 3.2.

If device implementations support any of the OpenGL ES versions, they:

  • [C-2-1] MUST report via the OpenGL ES managed APIs and native APIs any other OpenGL ES extensions they have implemented, and conversely MUST NOT report extension strings that they do not support.
  • [C-2-2] MUST support the EGL_KHR_image , EGL_KHR_image_base , EGL_ANDROID_image_native_buffer , EGL_ANDROID_get_native_client_buffer , EGL_KHR_wait_sync , EGL_KHR_get_all_proc_addresses , EGL_ANDROID_presentation_time , EGL_KHR_swap_buffers_with_damage , EGL_ANDROID_recordable , and EGL_ANDROID_GLES_layers extensions.
  • [C-SR] Are STRONGLY RECOMMENDED to support the EGL_KHR_partial_update and OES_EGL_image_external extensions.
  • SHOULD accurately report via the getString() method, any texture compression format that they support, which is typically vendor-specific.

If device implementations declare support for OpenGL ES 3.0, 3.1, or 3.2, they:

  • [C-3-1] MUST export the corresponding function symbols for these version in addition to the OpenGL ES 2.0 function symbols in the libGLESv2.so library.
  • [SR] Are STRONGLY RECOMMENDED to support the OES_EGL_image_external_essl3 extension.

If device implementations support OpenGL ES 3.2, they:

  • [C-4-1] MUST support the OpenGL ES Android Extension Pack in its entirety.

If device implementations support the OpenGL ES Android Extension Pack in its entirety, they:

  • [C-5-1] MUST identify the support through the android.hardware.opengles.aep feature flag.

If device implementations expose support for the EGL_KHR_mutable_render_buffer extension, they:

  • [C-6-1] MUST also support the EGL_ANDROID_front_buffer_auto_refresh extension.
7.1.4.2 Vulkan

Android includes support for Vulkan , a low-overhead, cross-platform API for high-performance 3D graphics.

If device implementations support OpenGL ES 3.1, they:

  • [SR] Are STRONGLY RECOMMENDED to include support for Vulkan 1.1.

If device implementations include a screen or video output, they:

  • SHOULD include support for Vulkan 1.1.

If device implementations include support for Vulkan 1.0, they:

  • [C-1-1] MUST report the correct integer value with the android.hardware.vulkan.level and android.hardware.vulkan.version feature flags.
  • [C-1-2] MUST enumerate, at least one VkPhysicalDevice for the Vulkan native API vkEnumeratePhysicalDevices() .
  • [C-1-3] MUST fully implement the Vulkan 1.0 APIs for each enumerated VkPhysicalDevice .
  • [C-1-4] MUST enumerate layers, contained in native libraries named as libVkLayer*.so in the application package's native library directory, through the Vulkan native APIs vkEnumerateInstanceLayerProperties() and vkEnumerateDeviceLayerProperties() .
  • [C-1-5] MUST NOT enumerate layers provided by libraries outside of the application package, or provide other ways of tracing or intercepting the Vulkan API, unless the application has the android:debuggable attribute set as true .
  • [C-1-6] MUST report all extension strings that they do support via the Vulkan native APIs , and conversely MUST NOT report extension strings that they do not correctly support.
  • [C-1-7] MUST support the VK_KHR_surface, VK_KHR_android_surface, VK_KHR_swapchain, and VK_KHR_incremental_present extensions.
  • [C-SR] Are STRONGLY RECOMMENDED to support the VK_KHR_driver_properties and VK_GOOGLE_display_timing extensions.

If device implementations do not include support for Vulkan 1.0, they:

  • [C-2-1] MUST NOT declare any of the Vulkan feature flags (eg android.hardware.vulkan.level , android.hardware.vulkan.version ).
  • [C-2-2] MUST NOT enumerate any VkPhysicalDevice for the Vulkan native API vkEnumeratePhysicalDevices() .

If device implementations include support for Vulkan 1.1 and declare any of the Vulkan feature flags, they:

  • [C-3-1] MUST expose support for the SYNC_FD external semaphore and handle types and the VK_ANDROID_external_memory_android_hardware_buffer extension.
7.1.4.3 RenderScript
  • [C-0-1] Device implementations MUST support Android RenderScript , as detailed in the Android SDK documentation.
7.1.4.4 2D Graphics Acceleration

Android includes a mechanism for applications to declare that they want to enable hardware acceleration for 2D graphics at the Application, Activity, Window, or View level through the use of a manifest tag android:hardwareAccelerated or direct API calls.

設備實現:

  • [C-0-1] MUST enable hardware acceleration by default, and MUST disable hardware acceleration if the developer so requests by setting android:hardwareAccelerated="false” or disabling hardware acceleration directly through the Android View APIs.
  • [C-0-2] MUST exhibit behavior consistent with the Android SDK documentation on hardware acceleration .

Android includes a TextureView object that lets developers directly integrate hardware-accelerated OpenGL ES textures as rendering targets in a UI hierarchy.

設備實現:

  • [C-0-3] MUST support the TextureView API, and MUST exhibit consistent behavior with the upstream Android implementation.
7.1.4.5 Wide-gamut Displays

If device implementations claim support for wide-gamut displays through Configuration.isScreenWideColorGamut() , they:

  • [C-1-1] MUST have a color-calibrated display.
  • [C-1-2] MUST have a display whose gamut covers the sRGB color gamut entirely in CIE 1931 xyY space.
  • [C-1-3] MUST have a display whose gamut has an area of at least 90% of DCI-P3 in CIE 1931 xyY space.
  • [C-1-4] MUST support OpenGL ES 3.1 or 3.2 and report it properly.
  • [C-1-5] MUST advertise support for the EGL_KHR_no_config_context , EGL_EXT_pixel_format_float , EGL_KHR_gl_colorspace , EGL_EXT_gl_colorspace_scrgb , EGL_EXT_gl_colorspace_scrgb_linear , EGL_EXT_gl_colorspace_display_p3 , EGL_EXT_gl_colorspace_display_p3_linear , and EGL_EXT_gl_colorspace_display_p3_passthrough extensions.
  • [C-SR] Are STRONGLY RECOMMENDED to support GL_EXT_sRGB .

Conversely, if device implementations do not support wide-gamut displays, they:

  • [C-2-1] SHOULD cover 100% or more of sRGB in CIE 1931 xyY space, although the screen color gamut is undefined.

7.1.5。舊版應用程式相容模式

Android specifies a “compatibility mode” in which the framework operates in a 'normal' screen size equivalent (320dp width) mode for the benefit of legacy applications not developed for old versions of Android that pre-date screen-size independence.

7.1.6。螢幕技術

The Android platform includes APIs that allow applications to render rich graphics to an Android-compatible display. Devices MUST support all of these APIs as defined by the Android SDK unless specifically allowed in this document.

All of a device implementation's Android-compatible displays:

  • [C-0-1] MUST be capable of rendering 16-bit color graphics.
  • SHOULD support displays capable of 24-bit color graphics.
  • [C-0-2] MUST be capable of rendering animations.
  • [C-0-3] MUST have a pixel aspect ratio (PAR) between 0.9 and 1.15. That is, the pixel aspect ratio MUST be near square (1.0) with a 10 ~ 15% tolerance.

7.1.7。輔助顯示器

Android includes support for secondary Android-compatible displays to enable media sharing capabilities and developer APIs for accessing external displays.

If device implementations support an external display either via a wired, wireless, or an embedded additional display connection, they:

  • [C-1-1] MUST implement the DisplayManager system service and API as described in the Android SDK documentation.

7.2.輸入裝置

設備實現:

7.2.1.鍵盤

If device implementations include support for third-party Input Method Editor (IME) applications, they:

Device implementations: * [C-0-1] MUST NOT include a hardware keyboard that does not match one of the formats specified in android.content.res.Configuration.keyboard (QWERTY or 12-key). * SHOULD include additional soft keyboard implementations. * MAY include a hardware keyboard.

7.2.2.非觸控式導航

Android includes support for d-pad, trackball, and wheel as mechanisms for non-touch navigation.

設備實現:

If device implementations lack non-touch navigations, they:

  • [C-1-1] MUST provide a reasonable alternative user interface mechanism for the selection and editing of text, compatible with Input Management Engines. The upstream Android open source implementation includes a selection mechanism suitable for use with devices that lack non-touch navigation inputs.

7.2.3.導航鍵

The Home , Recents , and Back functions typically provided via an interaction with a dedicated physical button or a distinct portion of the touch screen, are essential to the Android navigation paradigm and therefore, device implementations:

  • [C-0-1] MUST provide a user affordance to launch installed applications that have an activity with the <intent-filter> set with ACTION=MAIN and CATEGORY=LAUNCHER or CATEGORY=LEANBACK_LAUNCHER for Television device implementations. The Home function SHOULD be the mechanism for this user affordance.
  • SHOULD provide buttons for the Recents and Back function.

If the Home, Recents, or Back functions are provided, they:

  • [C-1-1] MUST be accessible with a single action (eg tap, double-click or gesture) when any of them are accessible.
  • [C-1-2] MUST provide a clear indication of which single action would trigger each function. Having a visible icon imprinted on the button, showing a software icon on the navigation bar portion of the screen, or walking the user through a guided step-by-step demo flow during the out- thr- through a guided step-by-step demo flow during the out- thr- through a guided step-by-step demo flow during the out-”指示。

設備實現:

  • [SR] are STRONGLY RECOMMENDED to not provide the input mechanism for the Menu function as it is deprecated in favor of action bar since Android 4.0.

If device implementations provide the Menu function, they:

  • [C-2-1] MUST display the action overflow button whenever the action overflow menu popup is not empty and the action bar is visible.
  • [C-2-2] MUST NOT modify the position of the action overflow popup displayed by selecting the overflow button in the action bar, but MAY render the action overflow popup at a mod position on the ifiedscreen render the action overflow popup at a mod position on the ifieden playen it playen playupby功能。

If device implementations do not provide the Menu function, for backwards compatibility, they: * [C-SR] Are STRONGLY RECOMMENDED make the Menu function available to applications when targetSdkVersion is lessware 10, is ware, 0, is lessware 10, is s 棕色, 0, is s 棕色, 0, 00 月, a soft is lessware 10, is phyor s , is lesswares softis.手勢。 This Menu function SHOULD be accessible unless hidden together with other navigation functions.

If device implementations provide the Assist function , they:

  • [C-4-1] MUST make the Assist function accessible with a single action (eg tap, double-click or gesture) when other navigation keys are accessible.
  • [SR] STRONGLY RECOMMENDED to use long press on HOME function as this designated interaction.

If device implementations use a distinct portion of the screen to display the navigation keys, they:

  • [C-5-1] Navigation keys MUST use a distinct portion of the screen, not available to applications, and MUST NOT obscure or otherwise interfere with the portion of the screen available to applications.
  • [C-5-2] MUST make available a portion of the display to applications that meets the requirements defined in section 7.1.1 .
  • [C-5-3] MUST honor the flags set by the app through the View.setSystemUiVisibility() API method, so that this distinct portion of the screen (aka the navigation bar) is properly hidden away as documented in the SDK.

If the navigation function is provided as an on-screen, gesture-based action:

If a navigation function is provided from anywhere on the left and right edges of the current orientation of the screen:

  • [C-7-1] The navigation function MUST be Back and provided as a swipe from both left and right edges of the current orientation of the screen.
  • [C-7-2] If custom swipeable system panels are provided on the left or right edges, they MUST be placed within the top 1/3rd of the screen with a clear, persistent visual indication that dragging in would invoke the aforementioned panels, and hence not Back. A system panel MAY be configured by a user such that it lands below the top 1/3rd of the screen edge(s) but the system panel MUST NOT use longer than 1/3rd of the edge(s).
  • [C-7-3] When the foreground app has either the View.SYSTEM_UI_FLAG_IMMERSIVE or View.SYSTEM_UI_FLAG_IMMERSIVE_STICKY flags set, swiping from the edges MUST behave as implemented in AOSP, which is documented in the SDK .
  • [C-7-4] When the foreground app has either the View.SYSTEM_UI_FLAG_IMMERSIVE or View.SYSTEM_UI_FLAG_IMMERSIVE_STICKY flags set, custom swipeable system panels MUST be hidden until the system br 點。

7.2.4.觸控螢幕輸入

Android includes support for a variety of pointer input systems, such as touchscreens, touch pads, and fake touch input devices. Touchscreen-based device implementations are associated with a display such that the user has the impression of directly manipulating items on screen. Since the user is directly touching the screen, the system does not require any additional affordances to indicate the objects being manipulated.

設備實現:

  • SHOULD have a pointer input system of some kind (either mouse-like or touch).
  • SHOULD support fully independently tracked pointers.

If device implementations include a touchscreen (single-touch or better), they:

  • [C-1-1] MUST report TOUCHSCREEN_FINGER for the Configuration.touchscreen API field.
  • [C-1-2] MUST report the android.hardware.touchscreen and android.hardware.faketouch feature flags.

If device implementations include a touchscreen that can track more than a single touch, they:

  • [C-2-1] MUST report the appropriate feature flags android.hardware.touchscreen.multitouch , android.hardware.touchscreen.multitouch.distinct , android.hardware.touchscreen.multitouch.jazzhand corresponding to the type of the specific touchscreen on the裝置.

If device implementations do not include a touchscreen (and rely on a pointer device only) and meet the fake touch requirements in section 7.2.5 , they:

  • [C-3-1] MUST NOT report any feature flag starting with android.hardware.touchscreen and MUST report only android.hardware.faketouch .

7.2.5.假觸摸輸入

Fake touch interface provides a user input system that approximates a subset of touchscreen capabilities. For example, a mouse or remote control that drives an on-screen cursor approximates touch, but requires the user to first point or focus then click. Numerous input devices like the mouse, trackpad, gyro-based air mouse, gyro-pointer, joystick, and multi-touch trackpad can support fake touch interactions. Android includes the feature constant android.hardware.faketouch, which corresponds to a high-fidelity non-touch (pointer-based) input device such as a mouse or trackpad that can adequately emulate touch-based input (including basic gesture support), and indicates that the device supports an emulated subset of touchscreen functionality.

If device implementations do not include a touchscreen but include another pointer input system which they want to make available, they:

  • SHOULD declare support for the android.hardware.faketouch feature flag.

If device implementations declare support for android.hardware.faketouch , they:

  • [C-1-1] MUST report the absolute X and Y screen positions of the pointer location and display a visual pointer on the screen.
  • [C-1-2] MUST report touch event with the action code that specifies the state change that occurs on the pointer going down or up on the screen .
  • [C-1-3] MUST support pointer down and up on an object on the screen, which allows users to emulate tap on an object on the screen.
  • [C-1-4] MUST support pointer down, pointer up, pointer down then pointer up in the same place on an object on the screen within a time threshold, which allows users to emulate double tap on an object on the screen.
  • [C-1-5] MUST support pointer down on an arbitrary point on the screen, pointer move to any other arbitrary point on the screen, followed by a pointer up, which allows users to emulate a touch drag.
  • [C-1-6] MUST support pointer down then allow users to quickly move the object to a different position on the screen and then pointer up on the screen, which allows users to fling an object on the screen.
  • [C-1-7] MUST report TOUCHSCREEN_NOTOUCH for the Configuration.touchscreen API field.

If device implementations declare support for android.hardware.faketouch.multitouch.distinct , they:

  • [C-2-1] MUST declare support for android.hardware.faketouch .
  • [C-2-2] MUST support distinct tracking of two or more independent pointer inputs.

If device implementations declare support for android.hardware.faketouch.multitouch.jazzhand , they:

  • [C-3-1] MUST declare support for android.hardware.faketouch .
  • [C-3-2] MUST support distinct tracking of 5 (tracking a hand of fingers) or more pointer inputs fully independently.

7.2.6。遊戲控制器支持

7.2.6.1.按鈕映射

If device implementations declare the android.hardware.gamepad feature flag, they:

  • [C-1-1] MUST have embed a controller or ship with a separate controller in the box, that would provide means to input all the events listed in the below tables.
  • [C-1-2] MUST be capable to map HID events to its associated Android view.InputEvent constants as listed in the below tables. The upstream Android implementation includes implementation for game controllers that satisfies this requirement.
按鈕HID Usage 2 Android Button
1 0x09 0x0001 KEYCODE_BUTTON_A (96)
1 0x09 0x0002 KEYCODE_BUTTON_B (97)
X 1 0x09 0x0004 KEYCODE_BUTTON_X (99)
Y 1 0x09 0x0005 KEYCODE_BUTTON_Y (100)
D-pad up 1
D-pad down 1
0x01 0x0039 3 AXIS_HAT_Y 4
D-pad left 1
D-pad right 1
0x01 0x0039 3 AXIS_HAT_X 4
Left shoulder button 1 0x09 0x0007 KEYCODE_BUTTON_L1 (102)
Right shoulder button 1 0x09 0x0008 KEYCODE_BUTTON_R1 (103)
Left stick click 1 0x09 0x000E KEYCODE_BUTTON_THUMBL (106)
Right stick click 1 0x09 0x000F KEYCODE_BUTTON_THUMBR (107)
首頁1 0x0c 0x0223 KEYCODE_HOME (3)
返回1 0x0c 0x0224 KEYCODE_BACK (4)

1 KeyEvent

2 The above HID usages MUST be declared within a Game pad CA (0x01 0x0005).

3 This usage MUST have a Logical Minimum of 0, a Logical Maximum of 7, a Physical Minimum of 0, a Physical Maximum of 315, Units in Degrees, and a Report Size of 4. The logical value is defined to be the clockwise rotation away from the vertical axis;例如,邏輯值0表示不旋轉且按下向上按鈕,而邏輯值1表示旋轉45度並且按下向上和向左鍵。

4 MotionEvent

Analog Controls 1 HID Usage Android Button
Left Trigger 0x02 0x00C5 AXIS_LTRIGGER
Right Trigger 0x02 0x00C4 AXIS_RTRIGGER
Left Joystick 0x01 0x0030
0x01 0x0031
AXIS_X
AXIS_Y
Right Joystick 0x01 0x0032
0x01 0x0035
AXIS_Z
AXIS_RZ

1 MotionEvent

7.2.7.遙控

See Section 2.3.1 for device-specific requirements.

7.3.感應器

If device implementations include a particular sensor type that has a corresponding API for third-party developers, the device implementation MUST implement that API as described in the Android SDK documentation and the Android Open Source documentation on sensors .

設備實現:

  • [C-0-1] MUST accurately report the presence or absence of sensors per the android.content.pm.PackageManager class.
  • [C-0-2] MUST return an accurate list of supported sensors via the SensorManager.getSensorList() and similar methods.
  • [C-0-3] MUST behave reasonably for all other sensor APIs (for example, by returning true or false as appropriate when applications attempt to register listeners, not calling sensor listeners when the corresponding sensors are not present; etc.).

If device implementations include a particular sensor type that has a corresponding API for third-party developers, they:

  • [C-1-1] MUST report all sensor measurements using the relevant International System of Units (metric) values for each sensor type as defined in the Android SDK documentation.
  • [C-1-2] MUST report sensor data with a maximum latency of 100 milliseconds + 2 * sample_time for the case of a sensor stream with a maximum requested latency of 0 ms when the application processor is active. This delay does not include any filtering delays.
  • [C-1-3] MUST report the first sensor sample within 400 milliseconds + 2 * sample_time of the sensor being activated. It is acceptable for this sample to have an accuracy of 0.
  • [SR] SHOULD report the event time in nanoseconds as defined in the Android SDK documentation, representing the time the event happened and synchronized with the SystemClock.elapsedRealtimeNano() clock. Existing and new Android devices are STRONGLY RECOMMENDED to meet these requirements so they will be able to upgrade to the future platform releases where this might become a REQUIRED component. The synchronization error SHOULD be below 100 milliseconds.

  • [C-1-4] For any API indicated by the Android SDK documentation to be a continuous sensor , device implementations MUST continuously provide periodic data samples that SHOULD have a jitter below 3%, where jitter is defined as the standard deviation of the difference of the reported timestamp values between consecutive events.

  • [C-1-5] MUST ensure that the sensor event stream MUST NOT prevent the device CPU from entering a suspend state or waking up from a suspend state.

  • When several sensors are activated, the power consumption SHOULD NOT exceed the sum of the individual sensor's reported power consumption.

上面的列表不全面; the documented behavior of the Android SDK and the Android Open Source Documentations on sensors is to be considered authoritative.

Some sensor types are composite, meaning they can be derived from data provided by one or more other sensors. (Examples include the orientation sensor and the linear acceleration sensor.)

設備實現:

  • SHOULD implement these sensor types, when they include the prerequisite physical sensors as described in sensor types .

If device implementations include a composite sensor, they:

  • [C-2-1] MUST implement the sensor as described in the Android Open Source documentation on composite sensors .

7.3.1.加速度計

設備實現:

  • [C-SR] Are STRONGLY RECOMMENDED to include a 3-axis accelerometer.

If device implementations include a 3-axis accelerometer, they:

  • [C-1-1] MUST be able to report events up to a frequency of at least 50 Hz.
  • [C-1-2] MUST implement and report TYPE_ACCELEROMETER sensor.
  • [C-1-3] MUST comply with the Android sensor coordinate system as detailed in the Android APIs.
  • [C-1-4] MUST be capable of measuring from freefall up to four times the gravity(4g) or more on any axis.
  • [C-1-5] MUST have a resolution of at least 12-bits.
  • [C-1-6] MUST have a standard deviation no greater than 0.05 m/s^, where the standard deviation SHOULD be calculated on a per axis basis on samples collected over a period of at least 3 seconds at the fastest sampling rate.
  • [SR] are STRONGLY RECOMMENDED to implement the TYPE_SIGNIFICANT_MOTION composite sensor.
  • [SR] are STRONGLY RECOMMENDED to implement and report TYPE_ACCELEROMETER_UNCALIBRATED sensor. Android devices are STRONGLY RECOMMENDED to meet this requirement so they will be able to upgrade to the future platform release where this might become REQUIRED.
  • SHOULD implement the TYPE_SIGNIFICANT_MOTION , TYPE_TILT_DETECTOR , TYPE_STEP_DETECTOR , TYPE_STEP_COUNTER composite sensors as described in the Android SDK document.
  • SHOULD report events up to at least 200 Hz.
  • SHOULD have a resolution of at least 16-bits.
  • SHOULD be calibrated while in use if the characteristics changes over the life cycle and compensated, and preserve the compensation parameters between device reboots.
  • SHOULD be temperature compensated.

If device implementations include a 3-axis accelerometer and any of the TYPE_SIGNIFICANT_MOTION , TYPE_TILT_DETECTOR , TYPE_STEP_DETECTOR , TYPE_STEP_COUNTER composite sensors are implemented:

  • [C-2-1] The sum of their power consumption MUST always be less than 4 mW.
  • SHOULD each be below 2 mW and 0.5 mW for when the device is in a dynamic or static condition.

If device implementations include a 3-axis accelerometer and a 3-axis gyroscope sensor, they:

  • [C-3-1] MUST implement the TYPE_GRAVITY and TYPE_LINEAR_ACCELERATION composite sensors.
  • [C-SR] Are STRONGLY RECOMMENDED to implement the TYPE_GAME_ROTATION_VECTOR composite sensor.

If device implementations include a 3-axis accelerometer, a 3-axis gyroscope sensor, and a magnetometer sensor, they:

  • [C-4-1] MUST implement a TYPE_ROTATION_VECTOR composite sensor.

7.3.2.磁力計

設備實現:

  • [C-SR] Are STRONGLY RECOMMENDED to include a 3-axis magnetometer (compass).

If device implementations include a 3-axis magnetometer, they:

  • [C-1-1] MUST implement the TYPE_MAGNETIC_FIELD sensor.
  • [C-1-2] MUST be able to report events up to a frequency of at least 10 Hz and SHOULD report events up to at least 50 Hz.
  • [C-1-3] MUST comply with the Android sensor coordinate system as detailed in the Android APIs.
  • [C-1-4] MUST be capable of measuring between -900 µT and +900 µT on each axis before saturating.
  • [C-1-5] MUST have a hard iron offset value less than 700 µT and SHOULD have a value below 200 µT, by placing the magnetometer far from dynamic (current-induced) and static (magnet-induced) magnetic fields.
  • [C-1-6] MUST have a resolution equal or denser than 0.6 µT.
  • [C-1-7] MUST support online calibration and compensation of the hard iron bias, and preserve the compensation parameters between device reboots.
  • [C-1-8] MUST have the soft iron compensation applied—the calibration can be done either while in use or during the production of the device.
  • [C-1-9] MUST have a standard deviation, calculated on a per axis basis on samples collected over a period of at least 3 seconds at the fastest sampling rate, no greater than 1.5 µT; SHOULD have a standard deviation no greater than 0.5 µT.
  • SHOULD implement TYPE_MAGNETIC_FIELD_UNCALIBRATED sensor.
  • [SR] Existing and new Android devices are STRONGLY RECOMMENDED to implement the TYPE_MAGNETIC_FIELD_UNCALIBRATED sensor.

If device implementations include a 3-axis magnetometer, an accelerometer sensor, and a 3-axis gyroscope sensor, they:

  • [C-2-1] MUST implement a TYPE_ROTATION_VECTOR composite sensor.

If device implementations include a 3-axis magnetometer, an accelerometer, they:

  • MAY implement the TYPE_GEOMAGNETIC_ROTATION_VECTOR sensor.

If device implementations include a 3-axis magnetometer, an accelerometer and TYPE_GEOMAGNETIC_ROTATION_VECTOR sensor, they:

  • [C-3-1] MUST consume less than 10 mW.
  • SHOULD consume less than 3 mW when the sensor is registered for batch mode at 10 Hz.

7.3.3.全球定位系統

設備實現:

  • [C-SR] Are STRONGLY RECOMMENDED to include a GPS/GNSS receiver.

If device implementations include a GPS/GNSS receiver and report the capability to applications through the android.hardware.location.gps feature flag, they:

  • [C-1-1] MUST support location outputs at a rate of at least 1 Hz when requested via LocationManager#requestLocationUpdate .
  • [C-1-2] MUST be able to determine the location in open-sky conditions (strong signals, negligible multipath, HDOP < 2) within 10 seconds (fast time to first fix), when connected to a 0.5 Mbps or faster data speed internet connection. This requirement is typically met by the use of some form of Assisted or Predicted GPS/GNSS technique to minimize GPS/GNSS lock-on time (Assistance data includes Reference Time, Reference Location and Satellite Ephemeris/Clock).
    • [C-1-6] After making such a location calculation, device implementations MUST determine its location, in open sky, within 5 seconds, when location requests are restarted, up to an hour after the initial location calculation, even when the subsequent request is made without a data connection, and/or after a power cycle.
  • In open sky conditions after determining the location, while stationary or moving with less than 1 meter per second squared of acceleration:

    • [C-1-3] MUST be able to determine location within 20 meters, and speed within 0.5 meters per second, at least 95% of the time.
    • [C-1-4] MUST simultaneously track and report via GnssStatus.Callback at least 8 satellites from one constellation.
    • 應能同時追蹤來自多個星座的至少 24 顆衛星(例如 GPS + 格洛納斯、北斗、伽利略中的至少一個)。
    • [C-SR] Are STRONGLY RECOMMENDED to continue to deliver normal GPS/GNSS location outputs through GNSS Location Provider APIs during an emergency phone call.
    • [C-SR] Are STRONGLY RECOMMENDED to report GNSS measurements from all constellations tracked (as reported in GnssStatus messages), with the exception of SBAS.
    • [C-SR] Are STRONGLY RECOMMENDED to report AGC, and Frequency of GNSS measurement.
    • [C-SR] Are STRONGLY RECOMMENDED to report all accuracy estimates (including Bearing, Speed, and Vertical) as part of each GPS/GNSS location.
    • [C-SR] Are STRONGLY RECOMMENDED to report GNSS measurements, as soon as they are found, even if a location calculated from GPS/GNSS is not yet reported.
    • [C-SR] Are STRONGLY RECOMMENDED to report GNSS pseudoranges and pseudorange rates, that, in open-sky conditions after determining the location, while stationary or moving with less than 0.2 meter per second squared of acceleration, are sufficient to calculate position within 20 meters, and speed within 0.2 meters per second, at least 95% of the time.

7.3.4.陀螺儀

設備實現:

  • [C-SR] Are STRONGLY RECOMMENDED to include a gyroscope sensor unless a 3-axis accelerometer is also included.

If device implementations include a 3-axis gyroscope, they:

  • [C-1-1] MUST be able to report events up to a frequency of at least 50 Hz.
  • [C-1-2] MUST implement the TYPE_GYROSCOPE sensor and are STRONGLY RECOMMENDED to also implement the TYPE_GYROSCOPE_UNCALIBRATED sensor.
  • [C-1-4] MUST have a resolution of 12-bits or more and SHOULD have a resolution of 16-bits or more.
  • [C-1-5] MUST be temperature compensated.
  • [C-1-6] MUST be calibrated and compensated while in use, and preserve the compensation parameters between device reboots.
  • [C-1-7] MUST have a variance no greater than 1e-7 rad^2 / s^2 per Hz (variance per Hz, or rad^2 / s). The variance is allowed to vary with the sampling rate, but MUST be constrained by this value. In other words, if you measure the variance of the gyro at 1 Hz sampling rate it SHOULD be no greater than 1e-7 rad^2/s^2.
  • [SR] Calibration error is STRONGLY RECOMMENDED to be less than 0.01 rad/s when device is stationary at room temperature.
  • SHOULD report events up to at least 200 Hz.

If device implementations include a 3-axis gyroscope, an accelerometer sensor and a magnetometer sensor, they:

  • [C-2-1] MUST implement a TYPE_ROTATION_VECTOR composite sensor.

If device implementations include a 3-axis accelerometer and a 3-axis gyroscope sensor, they:

  • [C-3-1] MUST implement the TYPE_GRAVITY and TYPE_LINEAR_ACCELERATION composite sensors.
  • [C-SR] Are STRONGLY RECOMMENDED to implement the TYPE_GAME_ROTATION_VECTOR composite sensor.

7.3.5.晴雨表

設備實現:

  • [C-SR] Are STRONGLY RECOMMENDED to include a barometer (ambient air pressure sensor).

If device implementations include a barometer, they:

  • [C-1-1] MUST implement and report TYPE_PRESSURE sensor.
  • [C-1-2] MUST be able to deliver events at 5 Hz or greater.
  • [C-1-3] MUST be temperature compensated.
  • [SR] STRONGLY RECOMMENDED to be able to report pressure measurements in the range 300hPa to 1100hPa.
  • SHOULD have an absolute accuracy of 1hPa.
  • SHOULD have a relative accuracy of 0.12hPa over 20hPa range (equivalent to ~1m accuracy over ~200m change at sea level).

7.3.6。溫度計

設備實現:

  • MAY include an ambient thermometer (temperature sensor).
  • MAY but SHOULD NOT include a CPU temperature sensor.

If device implementations include an ambient thermometer (temperature sensor), they:

  • [C-1-1] MUST be defined as SENSOR_TYPE_AMBIENT_TEMPERATURE and MUST measure the ambient (room/vehicle cabin) temperature from where the user is interacting with the device in degrees Celsius.
  • [C-1-2] MUST be defined as SENSOR_TYPE_TEMPERATURE .
  • [C-1-3] MUST measure the temperature of the device CPU.
  • [C-1-4] MUST NOT measure any other temperature.

Note the SENSOR_TYPE_TEMPERATURE sensor type was deprecated in Android 4.0.

7.3.7.光度計

  • Device implementations MAY include a photometer (ambient light sensor).

7.3.8.接近感測器

  • 設備實現可能包括接近感測器。

If device implementations include a proximity sensor, they:

  • [C-1-1] MUST measure the proximity of an object in the same direction as the screen.也就是說,必須將接近感測器定向以檢測靠近螢幕的對象,因為該感測器類型的主要目的是檢測使用者使用的手機。 If device implementations include a proximity sensor with any other orientation, it MUST NOT be accessible through this API.
  • [C-1-2] MUST have 1-bit of accuracy or more.

7.3.9.高保真感應器

If device implementations include a set of higher quality sensors as defined in this section, and make available them to third-party apps, they:

  • [C-1-1] MUST identify the capability through the android.hardware.sensor.hifi_sensors feature flag.

If device implementations declare android.hardware.sensor.hifi_sensors , they:

  • [C-2-1] MUST have a TYPE_ACCELEROMETER sensor which:

    • MUST have a measurement range between at least -8g and +8g, SHOULD have a measurement range between at least -16g and +16g.
    • MUST have a measurement resolution of at least 2048 LSB/g.
    • MUST have a minimum measurement frequency of 12.5 Hz or lower.
    • MUST have a maximum measurement frequency of 400 Hz or higher; SHOULD support the SensorDirectChannel RATE_VERY_FAST .
    • MUST have a measurement noise not above 400 μg/√Hz.
    • MUST implement a non-wake-up form of this sensor with a buffering capability of at least 3000 sensor events.
    • MUST have a batching power consumption not worse than 3 mW.
    • [C-SR] Is STRONGLY RECOMMENDED to have 3dB measurement bandwidth of at least 80% of Nyquist frequency, and white noise spectrum within this bandwidth.
    • SHOULD have an acceleration random walk less than 30 μg √Hz tested at room temperature.
    • SHOULD have a bias change vs. temperature of ≤ +/- 1 mg/°C.
    • SHOULD have a best-fit line non-linearity of ≤ 0.5%, and sensitivity change vs. temperature of ≤ 0.03%/C°.
    • SHOULD have cross-axis sensitivity of < 2.5 % and variation of cross-axis sensitivity < 0.2% in device operation temperature range.
  • [C-2-2] MUST have a TYPE_ACCELEROMETER_UNCALIBRATED with the same quality requirements as TYPE_ACCELEROMETER .

  • [C-2-3] MUST have a TYPE_GYROSCOPE sensor which:

    • MUST have a measurement range between at least -1000 and +1000 dps.
    • MUST have a measurement resolution of at least 16 LSB/dps.
    • MUST have a minimum measurement frequency of 12.5 Hz or lower.
    • MUST have a maximum measurement frequency of 400 Hz or higher; SHOULD support the SensorDirectChannel RATE_VERY_FAST .
    • MUST have a measurement noise not above 0.014°/s/√Hz.
    • [C-SR] Is STRONGLY RECOMMENDED to have 3dB measurement bandwidth of at least 80% of Nyquist frequency, and white noise spectrum within this bandwidth.
    • SHOULD have a rate random walk less than 0.001 °/s √Hz tested at room temperature.
    • SHOULD have a bias change vs. temperature of ≤ +/- 0.05 °/ s / °C.
    • SHOULD have a sensitivity change vs. temperature of ≤ 0.02% / °C.
    • SHOULD have a best-fit line non-linearity of ≤ 0.2%.
    • SHOULD have a noise density of ≤ 0.007 °/s/√Hz.
    • SHOULD have calibration error less than 0.002 rad/s in temperature range 10 ~ 40 ℃ when device is stationary.
    • SHOULD have g-sensitivity less than 0.1°/s/g.
    • SHOULD have cross-axis sensitivity of < 4.0 % and cross-axis sensitivity variation < 0.3% in device operation temperature range.
  • [C-2-4] MUST have a TYPE_GYROSCOPE_UNCALIBRATED with the same quality requirements as TYPE_GYROSCOPE .

  • [C-2-5] MUST have a TYPE_GEOMAGNETIC_FIELD sensor which:

    • MUST have a measurement range between at least -900 and +900 μT.
    • MUST have a measurement resolution of at least 5 LSB/uT.
    • MUST have a minimum measurement frequency of 5 Hz or lower.
    • MUST have a maximum measurement frequency of 50 Hz or higher.
    • MUST have a measurement noise not above 0.5 uT.
  • [C-2-6] MUST have a TYPE_MAGNETIC_FIELD_UNCALIBRATED with the same quality requirements as TYPE_GEOMAGNETIC_FIELD and in addition:

    • MUST implement a non-wake-up form of this sensor with a buffering capability of at least 600 sensor events.
    • [C-SR] Is STRONGLY RECOMMENDED to have white noise spectrum from 1 Hz to at least 10 Hz when the report rate is 50 Hz or higher.
  • [C-2-7] MUST have a TYPE_PRESSURE sensor which:

    • MUST have a measurement range between at least 300 and 1100 hPa.
    • MUST have a measurement resolution of at least 80 LSB/hPa.
    • MUST have a minimum measurement frequency of 1 Hz or lower.
    • MUST have a maximum measurement frequency of 10 Hz or higher.
    • MUST have a measurement noise not above 2 Pa/√Hz.
    • MUST implement a non-wake-up form of this sensor with a buffering capability of at least 300 sensor events.
    • MUST have a batching power consumption not worse than 2 mW.
  • [C-2-8] MUST have a TYPE_GAME_ROTATION_VECTOR sensor.
  • [C-2-9] MUST have a TYPE_SIGNIFICANT_MOTION sensor which:
    • MUST have a power consumption not worse than 0.5 mW when device is static and 1.5 mW when device is moving.
  • [C-2-10] MUST have a TYPE_STEP_DETECTOR sensor which:
    • MUST implement a non-wake-up form of this sensor with a buffering capability of at least 100 sensor events.
    • MUST have a power consumption not worse than 0.5 mW when device is static and 1.5 mW when device is moving.
    • MUST have a batching power consumption not worse than 4 mW.
  • [C-2-11] MUST have a TYPE_STEP_COUNTER sensor which:
    • MUST have a power consumption not worse than 0.5 mW when device is static and 1.5 mW when device is moving.
  • [C-2-12] MUST have a TILT_DETECTOR sensor which:
    • MUST have a power consumption not worse than 0.5 mW when device is static and 1.5 mW when device is moving.
  • [C-2-13] The event timestamp of the same physical event reported by the Accelerometer, Gyroscope, and Magnetometer MUST be within 2.5 milliseconds of each other. The event timestamp of the same physical event reported by the Accelerometer and Gyroscope SHOULD be within 0.25 milliseconds of each other.
  • [C-2-14] MUST have Gyroscope sensor event timestamps on the same time base as the camera subsystem and within 1 milliseconds of error.
  • [C-2-15] MUST deliver samples to applications within 5 milliseconds from the time when the data is available on any of the above physical sensors to the application.
  • [C-2-16] MUST NOT have a power consumption higher than 0.5 mW when device is static and 2.0 mW when device is moving when any combination of the following sensors are enabled:
    • SENSOR_TYPE_SIGNIFICANT_MOTION
    • SENSOR_TYPE_STEP_DETECTOR
    • SENSOR_TYPE_STEP_COUNTER
    • SENSOR_TILT_DETECTORS
  • [C-2-17] MAY have a TYPE_PROXIMITY sensor, but if present MUST have a minimum buffer capability of 100 sensor events.

Note that all power consumption requirements in this section do not include the power consumption of the Application Processor. It is inclusive of the power drawn by the entire sensor chain—the sensor, any supporting circuitry, any dedicated sensor processing system, etc.

If device implementations include direct sensor support, they:

  • [C-3-1] MUST correctly declare support of direct channel types and direct report rates level through the isDirectChannelTypeSupported and getHighestDirectReportRateLevel API.
  • [C-3-2] MUST support at least one of the two sensor direct channel types for all sensors that declare support for sensor direct channel.
  • SHOULD support event reporting through sensor direct channel for primary sensor (non-wakeup variant) of the following types:
    • TYPE_ACCELEROMETER
    • TYPE_ACCELEROMETER_UNCALIBRATED
    • TYPE_GYROSCOPE
    • TYPE_GYROSCOPE_UNCALIBRATED
    • TYPE_MAGNETIC_FIELD
    • TYPE_MAGNETIC_FIELD_UNCALIBRATED

7.3.10.生物辨識感測器

For additional background on Measuring Biometric Unlock Security, please see Measuring Biometric Security documentation .

If device implementations include a secure lock screen, they:

  • SHOULD include a biometric sensor

Biometric sensors can be classified as Strong , Weak , or Convenience based on their spoof and imposter acceptance rates, and on the security of the biometric pipeline. This classification determines the capabilities the biometric sensor has to interface with the platform and with third-party applications. Sensors are classified as Convenience by default, and need to meet additional requirements as detailed below if they wish to be classified as either Weak or Strong . Both Weak and Strong biometrics get additional capabilities as detailed below.

To make a biometric sensor available to third-party applications, device implementations:

  • [C-0-1] MUST meet the requirements for Strong or Weak biometric as defined in this document.

To allow access to keystore keys to third-party applications, device implementations:

  • [C-0-2] MUST meet the requirements for Strong as defined in this document.

另外:

  • [C-0-3] MUST be paired with an explicit confirm action (eg a button press) if that Strong biometric is passive (eg face or iris where no explicit signal of the user's intent exists).
    • [C-SR] The confirm action for passive biometrics is STRONGLY RECOMMENDED to be secured such that an operating system or kernel compromise cannot spoof it.為 example, this means that the confirm action based on a physical button is routed through an input-only general-purpose input/output (GPIO) pin of a secure element (SE) that cannot be driven than n drice 6按。

If device implementations wish to treat a biometric sensor as Convenience , they:

  • [C-1-1] MUST have a false acceptance rate less than 0.002%.
  • [C-1-2] MUST disclose that this mode may be less secure than a strong PIN, pattern, or password and clearly enumerate the risks of enabling it, if the spoof and imposter acceptance rates are higher than 7%.
  • [C-1-3] MUST rate limit attempts for at least 30 seconds after five false trials for biometric verification - where a false trial is one with an adequate capture quality ( BIOMETRIC_ACQUIRED_GOOD ) that does not match an enrolled biometric.
  • [C-1-4] MUST prevent adding new biometrics without first establishing a chain of trust by having the user confirm existing or add a new device credential (PIN/pattern/password) that's secured by TEE; the Android Open Source Project implementation provides the mechanism in the framework to do so.
  • [C-1-5] MUST completely remove all identifiable biometric data for a user when the user's account is removed (including via a factory reset).
  • [C-1-6] MUST honor the individual flag for that biometric (ie DevicePolicyManager.KEYGUARD_DISABLE_FINGERPRINT , DevicePolicymanager.KEYGUARD_DISABLE_FACE , or DevicePolicymanager.KEYGUARD_DISABLE_IRIS ).
  • [C-1-7] MUST challenge the user for the recommended primary authentication (eg PIN, pattern, password) once every 24 hours or less for new devices launching with Android version 10, once every 72 hours or less for devices upgrading from earlier Android version.
  • [C-1-8] MUST challenge the user for the recommended primary authentication (eg: PIN, pattern, password) after one of the following:

    • A 4-hour idle timeout period, OR
    • 3 failed biometric authentication attempts.
    • The idle timeout period and the failed authentication count is reset after any successful confirmation of the device credentials.

    Upgrading devices from an earlier Android version can be exempted from C-1-8.

  • [C-SR] Are STRONGLY RECOMMENDED to have a false rejection rate of less than 10%, as measured on the device.

  • [C-SR] Are STRONGLY RECOMMENDED to have a latency below 1 second, measured from when the biometric is detected, until the screen is unlocked, for each enrolled biometric.

If device implementations wish to treat a biometric sensor as Weak , they:

  • [C-2-1] MUST meet all requirements for Convenience above, except for [C-1-2].
  • [C-2-2] MUST have a spoof and imposter acceptance rate not higher than 20%.
  • [C-2-3] MUST have a hardware-backed keystore implementation, and perform the biometric matching in an isolated execution environment outside Android user or kernel space, such as the Trusted Execution Environment (TEE), or on a chip with a secure channel to the isolated execution environment.
  • [C-2-4] MUST have all identifiable data encrypted and cryptographically authenticated such that they cannot be acquired, read or altered outside of the isolated execution environment or a chip with a secure channel to the isolated execution environment as documented in the implementation guidelines on the Android Open Source Project site.
  • [C-2-5] For camera based biometrics, while biometric based authentication or enrollment is happening:
    • MUST operate the camera in a mode that prevents camera frames from being read or altered outside the isolated execution environment or a chip with a secure channel to the isolated execution environment.
    • For RGB single-camera solutions, the camera frames CAN be readable outside the isolated execution environment to support operations such as preview for enrollment, but MUST still NOT be alterable.
  • [C-2-6] MUST NOT enable third-party applications to distinguish between individual biometric enrollments.
  • [C-2-7] MUST NOT allow unencrypted access to identifiable biometric data or any data derived from it (such as embeddings) to the Application Processor outside the context of the TEE.
  • [C-2-8] MUST have a secure processing pipeline such that an operating system or kernel compromise cannot allow data to be directly injected to falsely authenticate as the user.

    If device implementations are already launched on an earlier Android version and cannot meet the requirement C-2-8 through a system software update, they MAY be exempted from the requirement.

If device implementations wish to treat a biometric sensor as Strong , they:

  • [C-3-1] MUST meet all the requirements of Weak above. Upgrading devices from an earlier Android version is not exempted from C-2-7.
  • [C-3-2] MUST have a spoof and imposter acceptance rate not higher than 7%.
  • [C-3-3] MUST challenge the user for the recommended primary authentication (eg PIN, pattern, password) once every 72 hours or less.

7.3.12.姿勢感測器

設備實現:

  • MAY support pose sensor with 6 degrees of freedom.

If device implementations support pose sensor with 6 degrees of freedom, they:

  • [C-1-1] MUST implement and report TYPE_POSE_6DOF sensor.
  • [C-1-2] MUST be more accurate than the rotation vector alone.

7.4.數據連接

7.4.1.電話

“Telephony” as used by the Android APIs and this document refers specifically to hardware related to placing voice calls and sending SMS messages via a GSM or CDMA network. While these voice calls may or may not be packet-switched, they are for the purposes of Android considered independent of any data connectivity that may be implemented using the same network. In other words, the Android “telephony” functionality and APIs refer specifically to voice calls and SMS. For instance, device implementations that cannot place calls or send/receive SMS messages are not considered a telephony device, regardless of whether they use a cellular network for data connectivity.

  • Android MAY be used on devices that do not include telephony hardware. That is, Android is compatible with devices that are not phones.

If device implementations include GSM or CDMA telephony, they:

  • [C-1-1] MUST declare the android.hardware.telephony feature flag and other sub-feature flags according to the technology.
  • [C-1-2] MUST implement full support for the API for that technology.

If device implementations do not include telephony hardware, they:

  • [C-2-1] MUST implement the full APIs as no-ops.

If device implementations support eUICCs or eSIMs/embedded SIMs and include a proprietary mechanism to make eSIM functionality available for third-party developers, they:

7.4.1.1.號碼屏蔽相容性

If device implementations report the android.hardware.telephony feature , they:

  • [C-1-1] MUST include number blocking support
  • [C-1-2] MUST fully implement BlockedNumberContract and the corresponding API as described in the SDK documentation.
  • [C-1-3] MUST block all calls and messages from a phone number in 'BlockedNumberProvider' without any interaction with apps. The only exception is when number blocking is temporarily lifted as described in the SDK documentation.
  • [C-1-4] MUST NOT write to the platform call log provider for a blocked call.
  • [C-1-5] MUST NOT write to the Telephony provider for a blocked message.
  • [C-1-6] MUST implement a blocked numbers management UI, which is opened with the intent returned by TelecomManager.createManageBlockedNumbersIntent() method.
  • [C-1-7] MUST NOT allow secondary users to view or edit the blocked numbers on the device as the Android platform assumes the primary user to have full control of the telephony services, a single instance, on the device. All blocking related UI MUST be hidden for secondary users and the blocked list MUST still be respected.
  • SHOULD migrate the blocked numbers into the provider when a device updates to Android 7.0.
7.4.1.2. Telecom API

If device implementations report android.hardware.telephony , they:

  • [C-1-1] MUST support the ConnectionService APIs described in the SDK .
  • [C-1-2] MUST display a new incoming call and provide user affordance to accept or reject the incoming call when the user is on an ongoing call that is made by a third-party app that does not support the hold feature specified via CAPABILITY_SUPPORT_HOLD .
  • [C-1-3] MUST have an application that implements InCallService .
  • [C-SR] Are STRONGLY RECOMMENDED to notify the user that answering an incoming call will drop an ongoing call.

    The AOSP implementation meets these requirements by a heads-up notification which indicates to the user that answering an incoming call will cause the other call to be dropped.

  • [C-SR] Are STRONGLY RECOMMENDED to preload the default dialer app that shows a call log entry and the name of a third-party app in its call log when the third-party app sets the EXTRA_LOG_SELF_MANAGED_CALLS extras key on its PhoneAccount to true .

  • [C-SR] Are STRONGLY RECOMMENDED to handle the audio headset's KEYCODE_MEDIA_PLAY_PAUSE and KEYCODE_HEADSETHOOK events for the android.telecom APIs as below:

7.4.2. IEEE 802.11(無線網路)

設備實現:

  • SHOULD include support for one or more forms of 802.11.

If device implementations include support for 802.11 and expose the functionality to a third-party application, they:

  • [C-1-1] MUST implement the corresponding Android API.
  • [C-1-2] MUST report the hardware feature flag android.hardware.wifi .
  • [C-1-3] MUST implement the multicast API as described in the SDK documentation.
  • [C-1-4] MUST support multicast DNS (mDNS) and MUST NOT filter mDNS packets (224.0.0.251) at any time of operation including:
    • Even when the screen is not in an active state.
    • For Android Television device implementations, even when in standby power states.
  • [C-1-5] MUST NOT treat the WifiManager.enableNetwork() API method call as a sufficient indication to switch the currently active Network that is used by default for application traffic and is returned by ConnectivityManager API methods such as getActiveNetwork and registerDefaultNetworkCallback . In other words, they MAY only disable the Internet access provided by any other network provider (eg mobile data) if they successfully validate that the Wi-Fi network is providing Internet access.
  • [C-1-6] Are STRONGLY RECOMMENDED to, when the ConnectivityManager.reportNetworkConnectivity() API method is called, re-evaluate the Internet access on the Network and, once the evaluation determines that the current Network no longer provides Internet access, switch to any other available network (eg mobile data) that provides Internet access.
  • [C-SR] Are STRONGLY RECOMMENDED to randomize the source MAC address and sequence number of probe request frames, once at the beginning of each scan, while STA is disconnected.
    • Each group of probe request frames comprising one scan SHOULD use one consistent MAC address (SHOULD NOT randomize MAC address halfway through a scan).
    • Probe request sequence number SHOULD iterate as normal (sequentially) between the probe requests in a scan.
    • Probe request sequence number SHOULD randomize between the last probe request of a scan and the first probe request of the next scan.
  • [C-SR] Are STRONGLY RECOMMENDED, while STA is disconnected, to allow only the following elements in probe request frames:
    • SSID Parameter Set (0)
    • DS Parameter Set (3)

If device implementations include support for Wi-Fi power save mode as defined in IEEE 802.11 standard, they:

  • [C-3-1] MUST turn off Wi-Fi power save mode whenever an app acquires WIFI_MODE_FULL_HIGH_PERF lock or WIFI_MODE_FULL_LOW_LATENCY lock via WifiManager.createWifiLock() and WifiManager.WifiLock.acquire() APIs and the lock is active.
  • [C-3-2] The average round trip latency between the device and an access point while the device is in a Wi-Fi Low Latency Lock ( WIFI_MODE_FULL_LOW_LATENCY ) mode MUST be smaller than the latency during a Wi-Fi High Perf Lock ( WIFI_MODE_FULL_HIGH_PERF ) mode.
  • [C-SR] Are STRONGLY RECOMMENDED to minimize Wi-Fi round trip latency whenever a Low Latency Lock ( WIFI_MODE_FULL_LOW_LATENCY ) is acquired and takes effect.

If device implementations support Wi-Fi and use Wi-Fi for location scanning, they:

7.4.2.1.無線直連

設備實現:

  • SHOULD include support for Wi-Fi Direct (Wi-Fi peer-to-peer).

If device implementations include support for Wi-Fi Direct, they:

  • [C-1-1] MUST implement the corresponding Android API as described in the SDK documentation.
  • [C-1-2] MUST report the hardware feature android.hardware.wifi.direct .
  • [C-1-3] MUST support regular Wi-Fi operation.
  • [C-1-4] MUST support Wi-Fi and Wi-Fi Direct operations concurrently.

設備實現:

If device implementations include support for TDLS and TDLS is enabled by the WiFiManager API, they:

  • [C-1-1] MUST declare support for TDLS through WifiManager.isTdlsSupported .
  • SHOULD use TDLS only when it is possible AND beneficial.
  • SHOULD have some heuristic and NOT use TDLS when its performance might be worse than going through the Wi-Fi access point.
7.4.2.3. Wi-Fi Aware

設備實現:

If device implementations include support for Wi-Fi Aware and expose the functionality to third-party apps, then they:

  • [C-1-1] MUST implement the WifiAwareManager APIs as described in the SDK documentation .
  • [C-1-2] MUST declare the android.hardware.wifi.aware feature flag.
  • [C-1-3] MUST support Wi-Fi and Wi-Fi Aware operations concurrently.
  • [C-1-4] MUST randomize the Wi-Fi Aware management interface address at intervals no longer than 30 minutes and whenever Wi-Fi Aware is enabled.

If device implementations include support for Wi-Fi Aware and Wi-Fi Location as described in Section 7.4.2.5 and exposes these functionalities to third-party apps, then they:

7.4.2.4. Wi-Fi Passpoint

設備實現:

If device implementations include support for Wi-Fi Passpoint, they:

  • [C-1-1] MUST implement the Passpoint related WifiManager APIs as described in the SDK documentation .
  • [C-1-2] MUST support IEEE 802.11u standard, specifically related to Network Discovery and Selection, such as Generic Advertisement Service (GAS) and Access Network Query Protocol (ANQP).

Conversely if device implementations do not include support for Wi-Fi Passpoint:

  • [C-2-1] The implementation of the Passpoint related WifiManager APIs MUST throw an UnsupportedOperationException .
7.4.2.5. Wi-Fi Location (Wi-Fi Round Trip Time - RTT)

設備實現:

If device implementations include support for Wi-Fi Location and expose the functionality to third-party apps, then they:

  • [C-1-1] MUST implement the WifiRttManager APIs as described in the SDK documentation .
  • [C-1-2] MUST declare the android.hardware.wifi.rtt feature flag.
  • [C-1-3] MUST randomize the source MAC address for each RTT burst which is executed while the Wi-Fi interface on which the RTT is being executed is not associated to an Access Point.
7.4.2.6. Wi-Fi Keepalive Offload

設備實現:

  • SHOULD include support for Wi-Fi keepalive offload.

If device implementations include support for Wi-Fi keepalive offload and expose the functionality to third-party apps, they:

  • [C-1-1] MUST support the SocketKeepAlive API.

  • [C-1-2] MUST support at least three concurrent keepalive slots over Wi-Fi and at least one keepalive slot over cellular.

If device implementations do not include support for Wi-Fi keepalive offload, they:

7.4.2.7. Wi-Fi Easy Connect (Device Provisioning Protocol)

設備實現:

If device implementations include support for Wi-Fi Easy Connect and expose the functionality to third-party apps, they:

7.4.3.藍牙

If device implementations support Bluetooth Audio profile, they:

  • SHOULD support Advanced Audio Codecs and Bluetooth Audio Codecs (eg LDAC).

If device implementations support HFP, A2DP and AVRCP, they:

  • SHOULD support at least 5 total connected devices.

If device implementations declare android.hardware.vr.high_performance feature, they:

  • [C-1-1] MUST support Bluetooth 4.2 and Bluetooth LE Data Length Extension.

Android includes support for Bluetooth and Bluetooth Low Energy .

If device implementations include support for Bluetooth and Bluetooth Low Energy, they:

  • [C-2-1] MUST declare the relevant platform features ( android.hardware.bluetooth and android.hardware.bluetooth_le respectively) and implement the platform APIs.
  • SHOULD implement relevant Bluetooth profiles such as A2DP, AVRCP, OBEX, HFP, etc. as appropriate for the device.

If device implementations include support for Bluetooth Low Energy, they:

  • [C-3-1] MUST declare the hardware feature android.hardware.bluetooth_le .
  • [C-3-2] MUST enable the GATT (generic attribute profile) based Bluetooth APIs as described in the SDK documentation and android.bluetooth .
  • [C-3-3] MUST report the correct value for BluetoothAdapter.isOffloadedFilteringSupported() to indicate whether the filtering logic for the ScanFilter API classes is implemented.
  • [C-3-4] MUST report the correct value for BluetoothAdapter.isMultipleAdvertisementSupported() to indicate whether Low Energy Advertising is supported.
  • SHOULD support offloading of the filtering logic to the bluetooth chipset when implementing the ScanFilter API .
  • SHOULD support offloading of the batched scanning to the bluetooth chipset.
  • SHOULD support multi advertisement with at least 4 slots.

  • [SR] STRONGLY RECOMMENDED to implement a Resolvable Private Address (RPA) timeout no longer than 15 minutes and rotate the address at timeout to protect user privacy.

If device implementations support Bluetooth LE and use Bluetooth LE for location scanning, they:

  • [C-4-1] MUST provide a user affordance to enable/disable the value read through the System API BluetoothAdapter.isBleScanAlwaysAvailable() .

If device implementations include support for Bluetooth LE and Hearing Aids Profile, as described in Hearing Aid Audio Support Using Bluetooth LE , they:

7.4.4.近場通訊

設備實現:

  • SHOULD include a transceiver and related hardware for Near-Field Communications (NFC).
  • [C-0-1] MUST implement android.nfc.NdefMessage and android.nfc.NdefRecord APIs even if they do not include support for NFC or declare the android.hardware.nfc feature as the classes represent a declare the android.hardware.nfc feature as the classes represent a protocol-presmatent as the classs represent a protocol. 。

If device implementations include NFC hardware and plan to make it available to third-party apps, they:

  • [C-1-1] MUST report the android.hardware.nfc feature from the android.content.pm.PackageManager.hasSystemFeature() method .
  • MUST be capable of reading and writing NDEF messages via the following NFC standards as below:
  • [C-1-2] MUST be capable of acting as an NFC Forum reader/writer (as defined by the NFC Forum technical specification NFCForum-TS-DigitalProtocol-1.0) via the following NFC standards:
    • NFCA(ISO14443-3A)
    • NFCB(ISO14443-3B)
    • NfcF (JIS X 6319-4)
    • ISODEP(ISO 14443-4)
    • NFC Forum Tag Types 1, 2, 3, 4, 5 (defined by the NFC Forum)
  • [SR] STRONGLY RECOMMENDED to be capable of reading and writing NDEF messages as well as raw data via the following NFC standards. Note that while the NFC standards are stated as STRONGLY RECOMMENDED, the Compatibility Definition for a future version is planned to change these to MUST. These standards are optional in this version but will be required in future versions. Existing and new devices that run this version of Android are VERY STRONGLY ENCOURAGED to meet these requirements now so they will be able to upgrade to the future platform releases.

  • [C-1-13] MUST poll for all supported technologies while in NFC discovery mode.

  • SHOULD be in NFC discovery mode while the device is awake with the screen active and the lock-screen unlocked.
  • SHOULD be capable of reading the barcode and URL (if encoded) of Thinfilm NFC Barcode products.

Note that publicly available links are not available for the JIS, ISO, and NFC Forum specifications cited above.

Android includes support for NFC Host Card Emulation (HCE) mode.

If device implementations include an NFC controller chipset capable of HCE (for NfcA and/or NfcB) and support Application ID (AID) routing, they:

  • [C-2-1] MUST report the android.hardware.nfc.hce feature constant.
  • [C-2-2] MUST support NFC HCE APIs as defined in the Android SDK.

If device implementations include an NFC controller chipset capable of HCE for NfcF, and implement the feature for third-party applications, they:

  • [C-3-1] MUST report the android.hardware.nfc.hcef feature constant.
  • [C-3-2] MUST implement the NfcF Card Emulation APIs as defined in the Android SDK.

If device implementations include general NFC support as described in this section and support MIFARE technologies (MIFARE Classic, MIFARE Ultralight, NDEF on MIFARE Classic) in the reader/writer role, they:

  • [C-4-1] MUST implement the corresponding Android APIs as documented by the Android SDK.
  • [C-4-2] MUST report the feature com.nxp.mifare from the android.content.pm.PackageManager.hasSystemFeature () method. Note that this is not a standard Android feature and as such does not appear as a constant in the android.content.pm.PackageManager class.

7.4.5。最低網路能力

設備實現:

  • [C-0-1] MUST include support for one or more forms of data networking. Specifically, device implementations MUST include support for at least one data standard capable of 200 Kbit/sec or greater. Examples of technologies that satisfy this requirement include EDGE, HSPA, EV-DO, 802.11g, Ethernet and Bluetooth PAN.
  • SHOULD also include support for at least one common wireless data standard, such as 802.11 (Wi-Fi), when a physical networking standard (such as Ethernet) is the primary data connection.
  • MAY implement more than one form of data connectivity.
  • [C-0-2] MUST include an IPv6 networking stack and support IPv6 communication using the managed APIs, such as java.net.Socket and java.net.URLConnection , as well as the native APIs, such as AF_INET6 sockets.
  • [C-0-3] MUST enable IPv6 by default.
  • MUST ensure that IPv6 communication is as reliable as IPv4, for example:
    • [C-0-4] MUST maintain IPv6 connectivity in doze mode.
    • [C-0-5] Rate-limiting MUST NOT cause the device to lose IPv6 connectivity on any IPv6-compliant network that uses RA lifetimes of at least 180 seconds.
  • [C-0-6] MUST provide third-party applications with direct IPv6 connectivity to the network when connected to an IPv6 network, without any form of address or port translation happening locally on the device. Both managed APIs such as Socket#getLocalAddress or Socket#getLocalPort ) and NDK APIs such as getsockname() or IPV6_PKTINFO MUST return the IP address and port that is actually used to send and receive packets on the network.

The required level of IPv6 support depends on the network type, as shown in the following requirements.

If device implementations support Wi-Fi, they:

  • [C-1-1] MUST support dual-stack and IPv6-only operation on Wi-Fi.

If device implementations support Ethernet, they:

  • [C-2-1] MUST support dual-stack operation on Ethernet.

If device implementations support Cellular data, they:

  • SHOULD support IPv6 operation (IPv6-only and possibly dual-stack) on cellular.

If device implementations support more than one network type (eg, Wi-Fi and cellular data), they:

  • [C-3-1] MUST simultaneously meet the above requirements on each network when the device is simultaneously connected to more than one network type.

7.4.6。同步設定

設備實現:

7.4.7。資料保護程式

If device implementations include a metered connection, they are:

  • [SR] STRONGLY RECOMMENDED to provide the data saver mode.

If device implementations provide the data saver mode, they:

If device implementations do not provide the data saver mode, they:

  • [C-2-1] MUST return the value RESTRICT_BACKGROUND_STATUS_DISABLED for ConnectivityManager.getRestrictBackgroundStatus()
  • [C-2-2] MUST NOT broadcast ConnectivityManager.ACTION_RESTRICT_BACKGROUND_CHANGED .
  • [C-2-3] MUST have an activity that handles the Settings.ACTION_IGNORE_BACKGROUND_DATA_RESTRICTIONS_SETTINGS intent but MAY implement it as a no-op.

7.4.8. Secure Elements

If device implementations support Open Mobile API capable secure elements and make them available to 3rd-party apps, they:

7.5。相機

If device implementations include at least one camera, they:

  • [C-1-1] MUST declare the android.hardware.camera.any feature flag.
  • [C-1-2] MUST be possible for an application 到 simultaneously allocate 3 RGBA_8888 bitmaps equal to the size of the images produced by the largest-resolution捕獲。
  • [C-1-3] MUST ensure that the preinstalled default camera application handling intents MediaStore.ACTION_IMAGE_CAPTURE , MediaStore.ACTION_IMAGE_CAPTURE_SECURE , or MediaStore.ACTION_VIDEO_CAPTURE , is responsible for removing the user location in the image metadata before sending it to the receiving application when the receiving application does not have ACCESS_FINE_LOCATION .

7.5.1.後置攝像頭

A rear-facing camera is a camera located on the side of the device opposite the display; that is, it images scenes on the far side of the device, like a traditional camera.

設備實現:

  • SHOULD include a rear-facing camera.

If device implementations include at least one rear-facing camera, they:

  • [C-1-1] MUST report the feature flag android.hardware.camera and android.hardware.camera.any .
  • [C-1-2] MUST have a resolution of at least 2 megapixels.
  • SHOULD have either hardware auto-focus or software auto-focus implemented in the camera driver (transparent to application software).
  • MAY have fixed-focus or EDOF (extended depth of field) hardware.
  • MAY include a flash.

If the camera includes a flash:

  • [C-2-1] the flash lamp MUST NOT be lit while an android.hardware.Camera.PreviewCallback instance has been registered on a Camera preview surface, unless the application has explicitly enabled the flash by enabling the FLASH_MODE_AUTO or FLASH_MODE_ON attributes of a Camera.Parameters object. Note that this constraint does not apply to the device's built-in system camera application, but only to third-party applications using Camera.PreviewCallback .

7.5.2.前置鏡頭

A front-facing camera is a camera located on the same side of the device as the display; that is, a camera typically used to image the user, such as for video conferencing and similar applications.

設備實現:

  • MAY include a front-facing camera.

If device implementations include at least one front-facing camera, they:

  • [C-1-1] MUST report the feature flag android.hardware.camera.any and android.hardware.camera.front .
  • [C-1-2] MUST have a resolution of at least VGA (640x480 pixels).
  • [C-1-3] MUST NOT use a front-facing camera as the default for the Camera API and MUST NOT configure the API to treat a front-facing camera as the default rear-facing camera, even if it is the only camera在設備上。
  • [C-1-4] The camera preview MUST be mirrored horizo​​​​ntally relative to the orientation specified by the application when the current application has explicitly requested that the Camera display be rotated via a call to the android.hardware.Camera.setDisplayOrientation() 。 Conversely, the preview MUST be mirrored along the device's default horizontal axis when the current application does not explicitly request that the Camera display be rotated via a call to the android.hardware.Camera.setDisplayOrientation() method.
  • [C-1-5] MUST NOT mirror the final captured still image or video streams returned to application callbacks or committed to media storage.
  • [C-1-6] MUST mirror the image displayed by the postview in the same manner as the camera preview image stream.
  • MAY include features (such as auto-focus, flash, etc.) available to rear-facing cameras as described in section 7.5.1 .

If device implementations are capable of being rotated by user (such as automatically via an accelerometer or manually via user input):

  • [C-2-1] The camera preview MUST be mirrored horizontally relative to the device's current orientation.

7.5.3.外接攝影機

設備實現:

  • MAY include support for an external camera that is not necessarily always connected.

If device implementations include support for an external camera, they:

  • [C-1-1] MUST declare the platform feature flag android.hardware.camera.external and android.hardware camera.any .
  • [C-1-2] MUST support USB Video Class (UVC 1.0 or higher) if the external camera connects through the USB host port.
  • [C-1-3] MUST pass camera CTS tests with a physical external camera device connected. Details of camera CTS testing are available at source.android.com .
  • SHOULD support video compressions such as MJPEG to enable transfer of high-quality unencoded streams (ie raw or independently compressed picture streams).
  • MAY support multiple cameras.
  • MAY support camera-based video encoding.

If camera-based video encoding is supported:

  • [C-2-1] A simultaneous unencoded / MJPEG stream (QVGA or greater resolution) MUST be accessible to the device implementation.

7.5.4.相機 API 行為

Android includes two API packages to access the camera, the newer android.hardware.camera2 API expose lower-level camera control to the app, including efficient zero-copy burst/streaming flows and per-frame controls of exposure, gain, white balance gains, color conversion, denoising, sharpening, and more.

The older API package, android.hardware.Camera , is marked as deprecated in Android 5.0 but as it SHOULD still be available for apps to use. Android device implementations MUST ensure the continued support of the API as described in this section and in the Android SDK.

All features that are common between the deprecated android.hardware.Camera class and the newer android.hardware.camera2 package MUST have equivalent performance and quality in both APIs. For example, with equivalent settings, autofocus speed and accuracy MUST be identical, and the quality of captured images MUST be the same. Features that depend on the different semantics of the two APIs are not required to have matching speed or quality, but SHOULD match as closely as possible.

Device implementations MUST implement the following behaviors for the camera-related APIs, for all available cameras.設備實現:

  • [C-0-1] MUST use android.hardware.PixelFormat.YCbCr_420_SP for preview data provided to application callbacks when an application has never called android.hardware.Camera.Parameters.setPreviewFormat(int) .
  • [C-0-2] MUST further be in the NV21 encoding format when an application registers an android.hardware.Camera.PreviewCallback instance and the system calls the onPreviewFrame() method and the preview format is YCbCr_420_SP, the data in the byte[] passed into onPreviewFrame() . That is, NV21 MUST be the default.
  • [C-0-3] MUST support the YV12 format (as denoted by the android.graphics.ImageFormat.YV12 constant) for camera previews for both front- and rear-facing cameras for android.hardware.Camera . (The hardware video encoder and camera may use any native pixel format, but the device implementation MUST support conversion to YV12.)
  • [C-0-4] MUST support the android.hardware.ImageFormat.YUV_420_888 and android.hardware.ImageFormat.JPEG formats as outputs through the android.media.ImageReader API for android.hardware.camera2 devices that advertise REQUEST_AVAILABLE_CAPABILITIES_BACKWARD_COMPATIBLE capability in android.request.availableCapabilities .
  • [C-0-5] MUST still implement the full Camera API included in the Android SDK documentation, regardless of whether the device includes hardware autofocus or other capabilities. For instance, cameras that lack autofocus MUST still call any registered android.hardware.Camera.AutoFocusCallback instances (even though this has no relevance to a non-autofocus camera.) Note that this does apply to front-facing cameras; for instance, even though most front-facing cameras do not support autofocus, the API callbacks MUST still be “faked” as described.
  • [C-0-6] MUST recognize and honor each parameter name defined as a constant in the android.hardware.Camera.Parameters class and the android.hardware.camera2.CaptureRequest class. Conversely, device implementations MUST NOT honor or recognize string constants passed to the android.hardware.Camera.setParameters() method other than those documented as constants on the android.hardware.Camera.Parameters . That is, device implementations MUST support all standard Camera parameters if the hardware allows, and MUST NOT support custom Camera parameter types. For instance, device implementations that support image capture using high dynamic range (HDR) imaging techniques MUST support camera parameter Camera.SCENE_MODE_HDR .
  • [C-0-7] MUST report the proper level of support with the android.info.supportedHardwareLevel property as described in the Android SDK and report the appropriate framework feature flags .
  • [C-0-8] MUST also declare its individual camera capabilities of android.hardware.camera2 via the android.request.availableCapabilities property and declare the appropriate feature flags ; MUST define the feature flag if any of its attached camera devices supports the feature.
  • [C-0-9] MUST broadcast the Camera.ACTION_NEW_PICTURE intent whenever a new picture is taken by the camera and the entry of the picture has been added to the media store.
  • [C-0-10] MUST broadcast the Camera.ACTION_NEW_VIDEO intent whenever a new video is recorded by the camera and the entry of the picture has been added to the media store.
  • [C-0-11] MUST have all cameras accessible via the deprecated android.hardware.Camera API also accessible via the android.hardware.camera2 API.
  • [C-SR] For devices with multiple RGB cameras facing in the same direction, are STRONGLY RECOMMENDED to support a logical camera device that lists capability CameraMetadata.REQUEST_AVAILABLE_CAPABILITIES_LOGICAL_MULTI_CAMERA , consisting of all of the RGB cameras facing that direction as physical sub-devices.

If device implementations provide a proprietary camera API to 3rd-party apps, they:

7.5.5。相機方向

If device implementations have a front- or a rear-facing camera, such camera(s):

  • [C-1-1] MUST be oriented so that the long dimension of the camera aligns with the screen's long dimension. That is, when the device is held in the landscape orientation, cameras MUST capture images in the landscape orientation. This applies regardless of the device's natural orientation; that is, it applies to landscape-primary devices as well as portrait-primary devices.

7.6。記憶體和儲存

7.6.1.最小內存和存儲

設備實現:

  • [C-0-1] MUST include a Download Manager that applications MAY use to download data files and they MUST be capable of downloading individual files of at least 100MB in size to the default “cache” location.

7.6.2.應用程式共享儲存

設備實現:

  • [C-0-1] MUST offer storage to be shared by applications, also often referred as “shared external storage”, "application shared storage" or by the Linux path "/sdcard" it is mounted on.
  • [C-0-2] MUST be configured with shared storage mounted by default, in other words “out of the box”, regardless of whether the storage is implemented on an internal storage component or a removable storageure eg )。
  • [C-0-3] MUST mount the application shared storage directly on the Linux path sdcard or include a Linux symbolic link from sdcard to the actual mount point.
  • [C-0-4] MUST enforce the android.permission.WRITE_EXTERNAL_STORAGE permission on this shared storage as documented in the SDK.
  • [C-0-5] MUST enable scoped storage by default for all apps targeting API level 29 or above, except in the following situations:
    • when the app was installed before the device upgraded to API level 29, regardless of the target API of the app.
    • when the app has requested android:requestLegacyExternalStorage="true" in their manifest.
    • when the app is granted the android.permission.WRITE_MEDIA_STORAGE permission.
  • [C-0-6] MUST enforce that apps with scoped storage enabled have no direct filesystem access to files outside of their application-specific directories, as returned by Context API methods such as Context.getExternalFilesDirs() , Context.getExternalCacheDirs() , Context.getExternalMediaDirs() , and Context.getObbDirs() methods.
  • [C-0-7] MUST redact location metadata, such as GPS Exif tags, stored in media files when those files are accessed through MediaStore , except when the calling app holds the ACCESS_MEDIA_LOCATION permission.

Device implementations MAY meet the above requirements using either of the following:

  • User-accessible removable storage, such as a Secure Digital (SD) card slot.
  • A portion of the internal (non-removable) storage as implemented in the Android Open Source Project (AOSP).

If device implementations use removable storage to satisfy the above requirements, they:

  • [C-1-1] MUST implement a toast or pop-up user interface warning the user when there is no storage medium inserted in the slot.
  • [C-1-2] MUST include a FAT-formatted storage medium (eg SD card) or show on the box and other material available at time of purchase that the storage medium has to be purchased separately.

If device implementations use a portion of the non-removable storage to satisfy the above requirements, they:

  • SHOULD use the AOSP implementation of the internal application shared storage.
  • MAY share the storage space with the application private data.

If device implementations include multiple shared storage paths (such as both an SD card slot and shared internal storage), they:

  • [C-2-1] MUST allow only pre-installed and privileged Android applications with the WRITE_MEDIA_STORAGE permission to write to the secondary external storage, except when writing to their package-specific directories or within the URI returned by firing the ACTION_OPEN_DOCUMENT_TREE intent.
  • [C-2-2] MUST require that the direct access associated with the android.permission.WRITE_MEDIA_STORAGE permission is only given to user-visible apps when the android.permission.WRITE_EXTERNAL_STORAGE permission is also granted.
  • [SR] STRONGLY RECOMMENDED that pre-installed and privileged Android applications use public APIs such as MediaStore to interact with storage devices, instead of relying on the direct access granted by android.permission.WRITE_MEDIA_STORAGE .

If device implementations have a USB port with USB peripheral mode support, they:

  • [C-3-1] MUST provide a mechanism to access the data on the application shared storage from a host computer.
  • SHOULD expose content from both storage paths transparently through Android's media scanner service and android.provider.MediaStore .
  • MAY use USB mass storage, but SHOULD use Media Transfer Protocol to satisfy this requirement.

If device implementations have a USB port with USB peripheral mode and support Media Transfer Protocol, they:

  • SHOULD be compatible with the reference Android MTP host, Android File Transfer .
  • SHOULD report a USB device class of 0x00.
  • SHOULD report a USB interface name of 'MTP'.

7.6.3.可採用的存儲

If the device is expected to be mobile in nature unlike Television, device implementations are:

  • [SR] STRONGLY RECOMMENDED to implement the adoptable storage in a long-term stable location, since accidentally disconnecting them can cause data loss/corruption.

If the removable storage device port is in a long-term stable location, such as within the battery compartment or other protective cover, device implementations are:

7.7. USB

If device implementations have a USB port, they:

  • SHOULD support USB peripheral mode and SHOULD support USB host mode.

7.7.1. USB週邊模式

If device implementations include a USB port supporting peripheral mode:

  • [C-1-1] The port MUST be connectable to a USB host that has a standard type-A or type-C USB port.
  • [C-1-2] MUST report the correct value of iSerialNumber in USB standard device descriptor through android.os.Build.SERIAL .
  • [C-1-3] MUST detect 1.5A and 3.0A chargers per the Type-C resistor standard and MUST detect changes in the advertisement if they support Type-C USB.
  • [SR] The port SHOULD use micro-B, micro-AB or Type-C USB form factor. Existing and new Android devices are STRONGLY RECOMMENDED to meet these requirements so they will be able to upgrade to the future platform releases.
  • [SR] The port SHOULD be located on the bottom of the device (according to natural orientation) or enable software screen rotation for all apps (including home screen), so that the display ws correctly when the home screen the so that the display ws correctly wsen the orm. 。 Existing and new Android devices are STRONGLY RECOMMENDED to meet these requirements so they will be able to upgrade to future platform releases.
  • [SR] SHOULD implement support to draw 1.5 A current during HS chirp and traffic as specified in the USB Battery Charging specification, revision 1.2 . Existing and new Android devices are STRONGLY RECOMMENDED to meet these requirements so they will be able to upgrade to the future platform releases.
  • [SR] STRONGLY RECOMMENDED to not support proprietary charging methods that modify Vbus voltage beyond default levels, or alter sink/source roles as such may result in interoperability issues with the chargers or devices that support the standard USB Power Delivery methods. While this is called out as "STRONGLY RECOMMENDED", in future Android versions we might REQUIRE all type-C devices to support full interoperability with standard type-C chargers.
  • [SR] STRONGLY RECOMMENDED to support Power Delivery for data and power role swapping when they support Type-C USB and USB host mode.
  • SHOULD support Power Delivery for high-voltage charging and support for Alternate Modes such as display out.
  • SHOULD implement the Android Open Accessory (AOA) API and specification as documented in the Android SDK documentation.

If device implementations include a USB port and implement the AOA specification, they:

  • [C-2-1] MUST declare support for the hardware feature android.hardware.usb.accessory .
  • [C-2-2] The USB mass storage class MUST include the string "android" at the end of the interface description iInterface string of the USB mass storage
  • SHOULD NOT implement AOAv2 audio documented in the Android Open Accessory Protocol 2.0 documentation. AOAv2 audio is deprecated as of Android version 8.0 (API level 26).

7.7.2. USB主機模式

If device implementations include a USB port supporting host mode, they:

  • [C-1-1] MUST implement the Android USB host API as documented in the Android SDK and MUST declare support for the hardware feature android.hardware.usb.host .
  • [C-1-2] MUST implement support to connect standard USB peripherals, in other words, they MUST either:
    • Have an on-device type C port or ship with cable(s) adapting an on-device proprietary port to a standard USB type-C port (USB Type-C device).
    • Have an on-device type A or ship with cable(s) adapting an on-device proprietary port to a standard USB type-A port.
    • Have an on-device micro-AB port, which SHOULD ship with a cable adapting to a standard type-A port.
  • [C-1-3] MUST NOT ship with an adapter converting from USB type A or micro-AB ports to a type-C port (receptacle).
  • [C-SR] Are STRONGLY RECOMMENDED to implement the USB audio class as documented in the Android SDK documentation.
  • SHOULD support charging the connected USB peripheral device while in host mode; advertising a source current of at least 1.5A as specified in the Termination Parameters section of the USB Type-C Cable and Connector Specification Revision 1.2 for USB Type-C connectors or using Charging Downstream Port(CDP) output current range as specified in the USB Battery Charging specifications, revision 1.2 for Micro-AB connectors.
  • SHOULD implement and support USB Type-C standards.

If device implementations include a USB port supporting host mode and the USB audio class, they:

  • [C-2-1] MUST support the USB HID class .
  • [C-2-2] MUST support the detection and mapping of the following HID data fields specified in the USB HID Usage Tables and the Voice Command Usage Request to the KeyEvent constants as below:
    • Usage Page (0xC) Usage ID (0x0CD): KEYCODE_MEDIA_PLAY_PAUSE
    • Usage Page (0xC) Usage ID (0x0E9): KEYCODE_VOLUME_UP
    • Usage Page (0xC) Usage ID (0x0EA): KEYCODE_VOLUME_DOWN
    • Usage Page (0xC) Usage ID (0x0CF): KEYCODE_VOICE_ASSIST

If device implementations include a USB port supporting host mode and the Storage Access Framework (SAF), they:

  • [C-3-1] MUST recognize any remotely connected MTP (Media Transfer Protocol) devices and make their contents accessible through the ACTION_GET_CONTENT , ACTION_OPEN_DOCUMENT , and ACTION_CREATE_DOCUMENT intents.

If device implementations include a USB port supporting host mode and USB Type-C, they:

  • [C-4-1] MUST implement Dual Role Port functionality as defined by the USB Type-C specification (section 4.5.1.3.3).
  • [SR] STRONGLY RECOMMENDED to support DisplayPort, SHOULD support USB SuperSpeed Data Rates, and are STRONGLY RECOMMENDED to support Power Delivery for data and power role swapping.
  • [SR] STRONGLY RECOMMENDED to NOT support Audio Adapter Accessory Mode as described in the Appendix A of the USB Type-C Cable and Connector Specification Revision 1.2 .
  • SHOULD implement the Try.* model that is most appropriate for the device form factor. For example a handheld device SHOULD implement the Try.SNK model.

7.8。聲音的

7.8.1.麥克風

If device implementations include a microphone, they:

  • [C-1-1] MUST report the android.hardware.microphone feature constant.
  • [C-1-2] MUST meet the audio recording requirements in section 5.4 .
  • [C-1-3] MUST meet the audio latency requirements in section 5.6 .
  • [SR] Are STRONGLY RECOMMENDED to support near-ultrasound recording as described in section 7.8.3 .

If device implementations omit a microphone, they:

  • [C-2-1] MUST NOT report the android.hardware.microphone feature constant.
  • [C-2-2] MUST implement the audio recording API at least as no-ops, per section 7 .

7.8.2.音訊輸出

If device implementations include a speaker or an audio/multimedia output port for an audio output peripheral such as a 4 conductor 3.5mm audio jack or USB host mode port using USB audio class , they:

  • [C-1-1] MUST report the android.hardware.audio.output feature constant.
  • [C-1-2] MUST meet the audio playback requirements in section 5.5 .
  • [C-1-3] MUST meet the audio latency requirements in section 5.6 .
  • [SR] STRONGLY RECOMMENDED to support near-ultrasound playback as described in section 7.8.3 .

If device implementations do not include a speaker or audio output port, they:

  • [C-2-1] MUST NOT report the android.hardware.audio.output feature.
  • [C-2-2] MUST implement the Audio Output related APIs as no-ops at least.

For the purposes of this section, an "output port" is a physical interface such as a 3.5mm audio jack, HDMI, or USB host mode port with USB audio class. Support for audio output over radio-based protocols such as Bluetooth, WiFi, or cellular network does not qualify as including an "output port".

7.8.2.1.類比音訊連接埠

In order to be compatible with the headsets and other audio accessories using the 3.5mm audio plug across the Android ecosystem, if device implementations include one or more analog audio ports, they:

  • [C-SR] Are STRONGLY RECOMMENDED to include at least one of the audio port(s) to be a 4 conductor 3.5mm audio jack.

If device implementations have a 4 conductor 3.5mm audio jack, they:

  • [C-1-1] MUST support audio playback to stereo headphones and stereo headsets with a microphone.
  • [C-1-2] MUST support TRRS audio plugs with the CTIA pin-out order.
  • [C-1-3] MUST support the detection and mapping to the keycodes for the following 3 ranges of equivalent impedance between the microphone and ground conductors on the audio plug:
    • 70 ohm or less : KEYCODE_HEADSETHOOK
    • 210-290 ohm : KEYCODE_VOLUME_UP
    • 360-680 ohm : KEYCODE_VOLUME_DOWN
  • [C-1-4] MUST trigger ACTION_HEADSET_PLUG upon a plug insert, but only after all contacts on plug are touching their relevant segments on the jack.
  • [C-1-5] MUST be capable of driving at least 150mV ± 10% of output voltage on a 32 ohm speaker impedance.
  • [C-1-6] MUST have a microphone bias voltage between 1.8V ~ 2.9V.
  • [C-1-7] MUST detect and map to the keycode for the following range of equivalent impedance between the microphone and ground conductors on the audio plug:
    • 110-180 ohm: KEYCODE_VOICE_ASSIST
  • [C-SR] Are STRONGLY RECOMMENDED to support audio plugs with the OMTP pin-out order.
  • [C-SR] Are STRONGLY RECOMMENDED to support audio recording from stereo headsets with a microphone.

If device implementations have a 4 conductor 3.5mm audio jack and support a microphone, and broadcast the android.intent.action.HEADSET_PLUG with the extra value microphone set as 1, they:

  • [C-2-1] MUST support the detection of microphone on the plugged in audio accessory.
7.8.2.2. Digital Audio Ports

In order to be compatible with the headsets and other audio accessories using USB-C connectors and implementing (USB audio class) across the Android ecosystem as defined in Android USB headset specification .

See Section 2.2.1 for device-specific requirements.

7.8.3。近超音波

Near-Ultrasound audio is the 18.5 kHz to 20 kHz band.

設備實現:

If PROPERTY_SUPPORT_MIC_NEAR_ULTRASOUND is "true", the following requirements MUST be met by the VOICE_RECOGNITION and UNPROCESSED audio sources:

  • [C-1-1] The microphone's mean power response in the 18.5 kHz to 20 kHz band MUST be no more than 15 dB below the response at 2 kHz.
  • [C-1-2] The microphone's unweighted signal to noise ratio over 18.5 kHz to 20 kHz for a 19 kHz tone at -26 dBFS MUST be no lower than 50 dB.

If PROPERTY_SUPPORT_SPEAKER_NEAR_ULTRASOUND is "true":

  • [C-2-1] The speaker's mean response in 18.5 kHz - 20 kHz MUST be no lower than 40 dB below the response at 2 kHz.

7.8.4。訊號完整性

設備實現:

  • SHOULD provide a glitch-free audio signal path for both input and output streams on handheld devices, as defined by zero glitches measured during a test of one minute per path. Test using [OboeTester] (https://github.com/google/oboe/tree/master/apps/OboeTester) “Automated Glitch Test”.

The test requires an audio loopback dongle , used directly in a 3.5mm jack, and/or in combination with a USB-C to 3.5mm adapter. All audio output ports SHOULD be tested.

OboeTester currently supports AAudio paths, so the following combinations SHOULD be tested for glitches using AAudio:

Perf Mode分享Out Sample Rate In Chans Out Chans
LOW_LATENCY獨家的未指定1 2
LOW_LATENCY獨家的未指定2 1
LOW_LATENCY共享未指定1 2
LOW_LATENCY共享未指定2 1
沒有任何共享48000 1 2
沒有任何共享48000 2 1
沒有任何共享44100 1 2
沒有任何共享44100 2 1
沒有任何共享16000 1 2
沒有任何共享16000 2 1

A reliable stream SHOULD meet the following criteria for Signal to Noise Ratio (SNR) and Total Harmonic Distortion (THD) for 2000 Hz sine.

感應器總諧波失真信噪比
primary built-in speaker, measured using an external reference microphone < 3.0% >= 50 dB
primary built-in microphone, measured using an external reference speaker < 3.0% >= 50 dB
built-in analog 3.5 mm jacks, tested using loopback adapter < 1% >= 60 dB
USB adapters supplied with the phone, tested using loopback adapter < 1.0% >= 60 dB

7.9。虛擬實境

Android includes APIs and facilities to build "Virtual Reality" (VR) applications including high quality mobile VR experiences. Device implementations MUST properly implement these APIs and behaviors, as detailed in this section.

7.9.1.虛擬實境模式

Android includes support for VR Mode , a feature which handles stereoscopic rendering of notifications and disables monocular system UI components while a VR application has user focus.

7.9.2. Virtual Reality Mode - High Performance

If device implementations support VR mode, they:

  • [C-1-1] MUST have at least 2 physical cores.
  • [C-1-2] MUST declare the android.hardware.vr.high_performance feature.
  • [C-1-3] MUST support sustained performance mode.
  • [C-1-4] MUST support OpenGL ES 3.2.
  • [C-1-5] MUST support android.hardware.vulkan.level 0.
  • SHOULD support android.hardware.vulkan.level 1 or higher.
  • [C-1-6] MUST implement EGL_KHR_mutable_render_buffer , EGL_ANDROID_front_buffer_auto_refresh , EGL_ANDROID_get_native_client_buffer , EGL_KHR_fence_sync , EGL_KHR_wait_sync , EGL_IMG_context_priority , EGL_EXT_protected_content , EGL_EXT_image_gl_colorspace , and expose the extensions in the list of available EGL extensions.
  • [C-1-8] MUST implement GL_EXT_multisampled_render_to_texture2 , GL_OVR_multiview , GL_OVR_multiview2 , GL_OVR_multiview_multisampled_render_to_texture , GL_EXT_protected_textures , and expose the extensions in the list of available GL extensions.
  • [C-SR] Are STRONGLY RECOMMENDED to implement GL_EXT_external_buffer , GL_EXT_EGL_image_array , and expose the extensions in the list of available GL extensions.
  • [C-SR] Are STRONGLY RECOMMENDED to support Vulkan 1.1.
  • [C-SR] Are STRONGLY RECOMMENDED to implement VK_ANDROID_external_memory_android_hardware_buffer , VK_GOOGLE_display_timing , VK_KHR_shared_presentable_image , and expose it in the list of available Vulkan extensions.
  • [C-SR] Are STRONGLY RECOMMENDED to expose at least one Vulkan queue family where flags contain both VK_QUEUE_GRAPHICS_BIT and VK_QUEUE_COMPUTE_BIT , and queueCount is at least 2.
  • [C-1-7] The GPU and display MUST be able to synchronize access to the shared front buffer such that alternating-eye rendering of VR content at 60fps with two render contexts will be displayed with no visible tearing artifacts.
  • [C-1-9] MUST implement support for AHardwareBuffer flags AHARDWAREBUFFER_USAGE_GPU_DATA_BUFFER , AHARDWAREBUFFER_USAGE_SENSOR_DIRECT_DATA and AHARDWAREBUFFER_USAGE_PROTECTED_CONTENT as described in the NDK.
  • [C-1-10] MUST implement support for AHardwareBuffer s with any combination of the usage flags AHARDWAREBUFFER_USAGE_GPU_COLOR_OUTPUT , AHARDWAREBUFFER_USAGE_GPU_SAMPLED_IMAGE , AHARDWAREBUFFER_USAGE_PROTECTED_CONTENT for at least the following formats: AHARDWAREBUFFER_FORMAT_R5G6B5_UNORM , AHARDWAREBUFFER_FORMAT_R8G8B8A8_UNORM , AHARDWAREBUFFER_FORMAT_R10G10B10A2_UNORM , AHARDWAREBUFFER_FORMAT_R16G16B16A16_FLOAT .
  • [C-SR] Are STRONGLY RECOMMENDED to support the allocation of AHardwareBuffer s with more than one layer and flags and formats specified in C-1-10.
  • [C-1-11] MUST support H.264 decoding at least 3840 x 2160 at 30fps, compressed to an average of 40Mbps (equivalent to 4 instances of 1920 x1080 at 30 fps-10 Mbps or 2 instances of 1920 x 1080 at 60 fps-20 Mbps).
  • [C-1-12] MUST support HEVC and VP9, MUST be capable of decoding at least 1920 x 1080 at 30 fps compressed to an average of 10 Mbps and SHOULD be capable of decoding 3840 x 2160 at 30 fps-20 Mbps (equivalent to 4 instances of 1920 x 1080 at 30 fps-5 Mbps).
  • [C-1-13] MUST support HardwarePropertiesManager.getDeviceTemperatures API and return accurate values for skin temperature.
  • [C-1-14] MUST have an embedded screen, and its resolution MUST be at least 1920 x 1080.
  • [C-SR] Are STRONGLY RECOMMENDED to have a display resolution of at least 2560 x 1440.
  • [C-1-15] The display MUST update at least 60 Hz while in VR Mode.
  • [C-1-17] The display MUST support a low-persistence mode with ≤ 5 milliseconds persistence, persistence being defined as the amount of time for which a pixel is emitting light.
  • [C-1-18] MUST support Bluetooth 4.2 and Bluetooth LE Data Length Extension section 7.4.3 .
  • [C-1-19] MUST support and properly report Direct Channel Type for all of the following default sensor types:
    • TYPE_ACCELEROMETER
    • TYPE_ACCELEROMETER_UNCALIBRATED
    • TYPE_GYROSCOPE
    • TYPE_GYROSCOPE_UNCALIBRATED
    • TYPE_MAGNETIC_FIELD
    • TYPE_MAGNETIC_FIELD_UNCALIBRATED
  • [C-SR] Are STRONGLY RECOMMENDED to support the TYPE_HARDWARE_BUFFER direct channel type for all Direct Channel Types listed above.
  • [C-1-21] MUST meet the gyroscope, accelerometer, and magnetometer related requirements for android.hardware.hifi_sensors , as specified in section 7.3.9 .
  • [C-SR] Are STRONGLY RECOMMENDED to support the android.hardware.sensor.hifi_sensors feature.
  • [C-1-22] MUST have end-to-end motion to photon latency not higher than 28 milliseconds.
  • [C-SR] Are STRONGLY RECOMMENDED to have end-to-end motion to photon latency not higher than 20 milliseconds.
  • [C-1-23] MUST have first-frame ratio, which is the ratio between the brightness of pixels on the first frame after a transition from black to white and the brightness of white pixels in steady state, of at least 85%.
  • [C-SR] Are STRONGLY RECOMMENDED to have first-frame ratio of at least 90%.
  • MAY provide an exclusive core to the foreground application and MAY support the Process.getExclusiveCores API to return the numbers of the cpu cores that are exclusive to the top foreground application.

If exclusive core is supported, then the core:

  • [C-2-1] MUST not allow any other userspace processes to run on it (except device drivers used by the application), but MAY allow some kernel processes to run as necessary.

8. 性能和功率

Some minimum performance and power criteria are critical to the user experience and impact the baseline assumptions developers would have when developing an app.

8.1.使用者體驗一致性

A smooth user interface can be provided to the end user if there are certain minimum requirements to ensure a consistent frame rate and response times for applications and games. Device implementations, depending on the device type, MAY have measurable requirements for the user interface latency and task switching as described in section 2 .

8.2.文件 I/O 存取效能

Providing a common baseline for a consistent file access performance on the application private data storage ( /data partition) allows app developers to set a proper expectation that would help their software design. Device implementations, depending on the device type, MAY have certain requirements described in section 2 for the following read and write operations:

  • Sequential write performance . Measured by writing a 256MB file using 10MB write buffer.
  • Random write performance . Measured by writing a 256MB file using 4KB write buffer.
  • Sequential read performance . Measured by reading a 256MB file using 10MB write buffer.
  • Random read performance . Measured by reading a 256MB file using 4KB write buffer.

8.3.省電模式

If device implementations include features to improve device power management that are included in AOSP or extend the features that are included in AOSP, they:

  • [C-1-1] MUST NOT deviate from the AOSP implementation for the triggering, maintenance, wakeup algorithms and the use of global system settings of App Standby and Doze power-saving modes.
  • [C-1-2] MUST NOT deviate from the AOSP implementation for the use of global settings to manage the throttling of jobs, alarm and network for apps in each bucket for App standby.
  • [C-1-3] MUST NOT deviate from the AOSP implementation for the number of the App Standby Buckets used for App Standby.
  • [C-1-4] MUST implement App Standby Buckets and Doze as described in Power Management .
  • [C-1-5] MUST return true for PowerManager.isPowerSaveMode() when the device is on power save mode.
  • [C-SR] Are STRONGLY RECOMMENDED to provide user affordance to enable and disable the battery saver feature.
  • [C-SR] Are STRONGLY RECOMMENDED to provide user affordance to display all Apps that are exempted from App Standby and Doze power-saving modes.

In addition to the power-saving modes, Android device implementations MAY implement any or all of the 4 sleeping power states as defined by the Advanced Configuration and Power Interface (ACPI).

If device implementations implement S4 power states as defined by the ACPI, they:

  • [C-1-1] MUST enter this state only after the user has taken an explicit action to put the device in an inactive state (eg by closing a lid that is physically part of the device or turning off a vehicle or television) and before the user re-activates the device (eg by opening the lid or turning the vehicle or television back on).

If device implementations implement S3 power states as defined by the ACPI, they:

  • [C-2-1] MUST meet C-1-1 above, or, MUST enter S3 state only when third-party applications do not need the system resources (eg the screen, CPU).

    Conversely, MUST exit from S3 state when third-party applications need the system resources, as described on this SDK.

    For example, while the third-party applications request to keep the screen on through FLAG_KEEP_SCREEN_ON or keep CPU running through PARTIAL_WAKE_LOCK , the device MUST NOT enter S3 state unless, as described in C-1-1, the user has taken explicit action to put the device in an inactive state. Conversely, at a time when a task that third-party apps implement through JobScheduler is triggered or Firebase Cloud Messaging is delivered to third-party apps, the device MUST exit the S3 state unless the user has put the device in an inactive state. These are not comprehensive examples and AOSP implements extensive wake-up signals that trigger a wakeup from this state.

8.4.用電核算

A more accurate accounting and reporting of the power consumption provides the app developer both the incentives and the tools to optimize the power usage pattern of the application.

設備實現:

  • [SR] STRONGLY RECOMMENDED to provide a per-component power profile that defines the current consumption value for each hardware component and the approximate battery drain caused by the components over time as documented in the Android Open Source Project site.
  • [SR] STRONGLY RECOMMENDED to report all power consumption values in milliampere hours (mAh).
  • [SR] STRONGLY RECOMMENDED to report CPU power consumption per each process's UID. The Android Open Source Project meets the requirement through the uid_cputime kernel module implementation.
  • [SR] STRONGLY RECOMMENDED to make this power usage available via the adb shell dumpsys batterystats shell command to the app developer.
  • SHOULD be attributed to the hardware component itself if unable to attribute hardware component power usage to an application.

8.5。一致的性能

Performance can fluctuate dramatically for high-performance long-running apps, either because of the other apps running in the background or the CPU throttling due to temperature limits. Android includes programmatic interfaces so that when the device is capable, the top foreground application can request that the system optimize the allocation of the resources to address such fluctuations.

設備實現:

If device implementations report support of Sustained Performance Mode, they:

  • [C-1-1] MUST provide the top foreground application a consistent level of performance for at least 30 minutes, when the app requests it.
  • [C-1-2] MUST honor the Window.setSustainedPerformanceMode() API and other related APIs.

If device implementations include two or more CPU cores, they:

  • SHOULD provide at least one exclusive core that can be reserved by the top foreground application.

If device implementations support reserving one exclusive core for the top foreground application, they:

  • [C-2-1] MUST report through the Process.getExclusiveCores() API method the ID numbers of the exclusive cores that can be reserved by the top foreground application.
  • [C-2-2] MUST not allow any user space processes except the device drivers used by the application to run on the exclusive cores, but MAY allow some kernel processes to run as necessary.

If device implementations do not support an exclusive core, they:

9. 安全模型相容性

設備實現:

  • [C-0-1] MUST implement a security model consistent with the Android platform security model as defined in Security and Permissions reference document in the APIs in the Android developer documentation.

  • [C-0-2] MUST support installation of self-signed applications without requiring any additional permissions/certificates from any third parties/authorities. Specifically, compatible devices MUST support the security mechanisms described in the following subsections.

9.1.權限

設備實現:

  • [C-0-1] MUST support the Android permissions model as defined in the Android developer documentation. Specifically, they MUST enforce each permission defined as described in the SDK documentation; no permissions may be omitted, altered, or ignored.

  • MAY add additional permissions, provided the new permission ID strings are not in the android.\* namespace.

  • [C-0-2] Permissions with a protectionLevel of PROTECTION_FLAG_PRIVILEGED MUST only be granted to apps preinstalled in the privileged path(s) of the system image and within the subset of the explicitly allowlisted permissions for each app. The AOSP implementation meets this requirement by reading and honoring the allowlisted permissions for each app from the files in the etc/permissions/ path and using the system/priv-app path as the privileged path.

Permissions with a protection level of dangerous are runtime permissions. Applications with targetSdkVersion > 22 request them at runtime.

設備實現:

  • [C-0-3] MUST show a dedicated interface for the user to decide whether to grant the requested runtime permissions and also provide an interface for the user to manage runtime permissions.
  • [C-0-4] MUST have one and only one implementation of both user interfaces.
  • [C-0-5] MUST NOT grant any runtime permissions to preinstalled apps unless:
    • The user's consent can be obtained before the application uses it.
    • The runtime permissions are associated with an intent pattern for which the preinstalled application is set as the default handler.
  • [C-0-6] MUST grant the android.permission.RECOVER_KEYSTORE permission only to system apps that register a properly secured Recovery Agent. A properly secured Recovery Agent is defined as an on-device software agent that synchronizes with an off-device remote storage, that is equipped with secure hardware with protection equivalent or stronger than what is described in Google Cloud Key Vault Service to prevent brute-force attacks on the lockscreen knowledge factor.

設備實現:

  • [C-0-7] MUST adhere to Android location permission properties when an app requests the location or physical activity data through standard Android API or proprietary mechanism. Such data includes but not limited to:

    • Device's location (eg latitude and longitude).
    • Information that can be used to determine or estimate the device's location (eg SSID, BSSID, Cell ID, Bluetooth scans, or location of the network that the device is connected to).
    • User's physical activity or classification of the physical activity.

More specifically, device implementations:

  • [C-0-8] MUST obtain user consent to allow an app to access the location or physical activity data.
  • [C-0-9] MUST grant a runtime permission ONLY to the app that holds sufficient permission as described on SDK. For example, TelephonyManager#getServiceState requires android.permission.ACCESS_FINE_LOCATION ).

Permissions can be marked as restricted altering their behavior.

  • [C-0-10] Permissions marked with the flag hardRestricted MUST NOT be granted to an app unless:

    • An app APK file is in the system partition.
    • The user assigns a role that is associated with the hardRestricted permissions to an app.
    • The installer grants the hardRestricted to an app.
    • An app is granted the hardRestricted on an earlier Android version.
  • [C-0-11] Apps holding a softRestricted permission MUST get only limited access and MUST NOT gain full access until added to an allowlist as described in the SDK, where full and limited access is defined for each softRestricted permission (for example, WRITE_EXTERNAL_STORAGE and READ_EXTERNAL_STORAGE ).

If device implementations include a pre-installed app or wish to allow third-party apps to access the usage statistics, they:

  • [SR] are STRONGLY RECOMMENDED provide user-accessible mechanism to grant or revoke access to the usage stats in response to the android.settings.ACTION_USAGE_ACCESS_SETTINGS intent for apps that declare the android.permission.PACKAGE_USAGE_STATS permission.

If device implementations intend to disallow any apps, including pre-installed apps, from accessing the usage statistics, they:

  • [C-1-1] MUST still have an activity that handles the android.settings.ACTION_USAGE_ACCESS_SETTINGS intent pattern but MUST implement it as a no-op, that is to have an equivalent behavior as when the user is declined for access.

9.2. UID 和進程隔離

設備實現:

  • [C-0-1] MUST support the Android application sandbox model, in which each application runs as a unique Unixstyle UID and in a separate process.
  • [C-0-2] MUST support running multiple applications as the same Linux user ID, provided that the applications are properly signed and constructed, as defined in the Security and Permissions reference .

9.3.檔案系統權限

設備實現:

9.4.備用執行環境

Device implementations MUST keep consistency of the Android security and permission model, even if they include runtime environments that execute applications using some other software or technology than the Dalvik Executable Format or native code.換句話說:

  • [C-0-1] Alternate runtimes MUST themselves be Android applications, and abide by the standard Android security model, as described elsewhere in section 9 .

  • [C-0-2] Alternate runtimes MUST NOT be granted access to resources protected by permissions not requested in the runtime's AndroidManifest.xml file via the < uses-permission > mechanism.

  • [C-0-3] Alternate runtimes MUST NOT permit applications to make use of features protected by Android permissions restricted to system applications.

  • [C-0-4] Alternate runtimes MUST abide by the Android sandbox model and installed applications using an alternate runtime MUST NOT reuse the sandbox of any other app installed on the device, exception the sandbox of any other app installed on the device, exceptity 。

  • [C-0-5] Alternate runtimes MUST NOT launch with, grant, or be granted access to the sandboxes corresponding to other Android applications.

  • [C-0-6] Alternate runtimes MUST NOT be launched with, be granted, or grant to other applications any privileges of the superuser (root), or of any other user ID.

  • [C-0-7] When the .apk files of alternate runtimes are included in the system image of device implementations, it MUST be signed with a key distinct from the key used to sign other applications included with the device implementations.

  • [C-0-8] When installing applications, alternate runtimes MUST obtain user consent for the Android permissions used by the application.

  • [C-0-9] When an application needs to make use of a device resource for which there is a corresponding Android permission (such as Camera, GPS, etc.), the alternate runtime MUST inform the user that the application will be able to access that resource.

  • [C-0-10] When the runtime environment does not record application capabilities in this manner, the runtime environment MUST list all permissions held by the runtime itself when installing any application using that runtime.

  • Alternate runtimes SHOULD install apps via the PackageManager into separate Android sandboxes (Linux user IDs, etc.).

  • Alternate runtimes MAY provide a single Android sandbox shared by all applications using the alternate runtime.

9.5。多用戶支援

Android includes support for multiple users and provides support for full user isolation.

  • Device implementations MAY but SHOULD NOT enable multi-user if they use removable media for primary external storage.

If device implementations include multiple users, they:

  • [C-1-1] MUST meet the following requirements related to multi-user support .
  • [C-1-2] MUST, for each user, implement a security model consistent with the Android platform security model as defined in Security and Permissions reference document in the APIs.
  • [C-1-3] MUST have separate and isolated shared application storage (aka /sdcard ) directories for each user instance.
  • [C-1-4] MUST ensure that applications owned by and running on behalf a given user cannot list, read, or write to the files owned by any other user, even if the data of both users are stored on the or文件系統。
  • [C-1-5] MUST encrypt the contents of the SD card when multiuser is enabled using a key stored only on non-removable media accessible only to the system if device implementations use removable media for the external storage APIs. As this will make the media unreadable by a host PC, device implementations will be required to switch to MTP or a similar system to provide host PCs with access to the current user's data.

9.6。高級簡訊警告

Android includes support for warning users of any outgoing premium SMS message . Premium SMS messages are text messages sent to a service registered with a carrier that may incur a charge to the user.

If device implementations declare support for android.hardware.telephony , they:

  • [C-1-1] MUST warn users before sending a SMS message to numbers identified by regular expressions defined in /data/misc/sms/codes.xml file in the device. The upstream Android Open Source Project provides an implementation that satisfies this requirement.

9.7.安全特性

Device implementations MUST ensure compliance with security features in both the kernel and platform as described below.

The Android Sandbox includes features that use the Security-Enhanced Linux (SELinux) mandatory access control (MAC) system, seccomp sandboxing, and other security features in the Linux kernel.設備實現:

  • [C-0-1] MUST maintain compatibility with existing applications, even when SELinux or any other security features are implemented below the Android framework.
  • [C-0-2] MUST NOT have a visible user interface when a security violation is detected and successfully blocked by the security feature implemented below the Android fr時開發。
  • [C-0-3] MUST NOT make SELinux or any other security features implemented below the Android framework configurable to the user or app developer.
  • [C-0-4] MUST NOT allow an application that can affect another application through an API (such as a Device Administration API) to configure a policy that breaks compatibility.
  • [C-0-5] MUST split the media framework into multiple processes so that it is possible to more narrowly grant access for each process as described in the Android Open Source Project site.
  • [C-0-6] MUST implement a kernel application sandboxing mechanism which allows filtering of system calls using a configurable policy from multithreaded programs. The upstream Android Open Source Project meets this requirement through enabling the seccomp-BPF with threadgroup synchronization (TSYNC) as described in the Kernel Configuration section of source.android.com .

Kernel integrity and self-protection features are integral to Android security.設備實現:

  • [C-0-7] MUST implement kernel stack buffer overflow protection mechanisms. Examples of such mechanisms are CC_STACKPROTECTOR_REGULAR and CONFIG_CC_STACKPROTECTOR_STRONG .
  • [C-0-8] MUST implement strict kernel memory protections where executable code is read-only, read-only data is non-executable and non-writable, and writable data is non-executable (eg CONFIG_DEBUG_RODATA or CONFIG_STRICT_KERNEL_RWX ).
  • [C-0-9] MUST implement static and dynamic object size bounds checking of copies between user-space and kernel-space (eg CONFIG_HARDENED_USERCOPY ) on devices originally shipping with API level 28 or higher.
  • [C-0-10] MUST NOT execute user-space memory when executing in the kernel mode (eg hardware PXN, or emulated via CONFIG_CPU_SW_DOMAIN_PAN or CONFIG_ARM64_SW_TTBR0_PAN ) on devices originally shipping with API level 28 or higher.
  • [C-0-11] MUST NOT read or write user-space memory in the kernel outside of normal usercopy access APIs (eg hardware PAN, or emulated via CONFIG_CPU_SW_DOMAIN_PAN or CONFIG_ARM64_SW_TTBR0_PAN ) on devices originally shipping with API level 28 or higher.
  • [C-0-12] MUST implement kernel page table isolation if the hardware is vulnerable to CVE-2017-5754 on all devices originally shipping with API level 28 or higher (eg CONFIG_PAGE_TABLE_ISOLATION or CONFIG_UNMAP_KERNEL_AT_EL0 ).
  • [C-0-13] MUST implement branch prediction hardening if the hardware is vulnerable to CVE-2017-5715 on all devices originally shipping with API level 28 or higher (eg CONFIG_HARDEN_BRANCH_PREDICTOR ).
  • [SR] STRONGLY RECOMMENDED to keep kernel data which is written only during initialization marked read-only after initialization (eg __ro_after_init ).
  • [C-SR] Are STRONGLY RECOMMENDED to randomize the layout of the kernel code and memory, and to avoid exposures that would compromise the randomization (eg CONFIG_RANDOMIZE_BASE with bootloader entropy via the /chosen/kaslr-seed Device Tree node or EFI_RNG_PROTOCOL ).

  • [C-SR] Are STRONGLY RECOMMENDED to enable control flow integrity (CFI) in the kernel to provide additional protection against code-reuse attacks (eg CONFIG_CFI_CLANG and CONFIG_SHADOW_CALL_STACK ).

  • [C-SR] Are STRONGLY RECOMMENDED not to disable Control-Flow Integrity (CFI), Shadow Call Stack (SCS) or Integer Overflow Sanitization (IntSan) on components that have it enabled.
  • [C-SR] Are STRONGLY RECOMMENDED to enable CFI, SCS, and IntSan for any additional security-sensitive userspace components as explained in CFI and IntSan .

If device implementations use a Linux kernel, they:

  • [C-1-1] MUST implement SELinux.
  • [C-1-2] MUST set SELinux to global enforcing mode.
  • [C-1-3] MUST configure all domains in enforcing mode. No permissive mode domains are allowed, including domains specific to a device/vendor.
  • [C-1-4] MUST NOT modify, omit, or replace the neverallow rules present within the system/sepolicy folder provided in the upstream Android Open Source Project (AOSP) and the policy MUST compile with all neverallow rules present, for both AOSP SELinux domains as well as device/vendor specific domains.
  • [C-1-5] MUST run third-party applications targeting API level 28 or higher in per-application SELinux sandboxes with per-app SELinux restrictions on each application's private data directory.
  • SHOULD retain the default SELinux policy provided in the system/sepolicy folder of the upstream Android Open Source Project and only further add to this policy for their own device-specific configuration.

If device implementations use kernel other than Linux, they:

  • [C-2-1] MUST use a mandatory access control system that is equivalent to SELinux.

Android contains multiple defense-in-depth features that are integral to device security.

9.8.隱私

9.8.1.使用歷史

Android stores the history of the user's choices and manages such history by UsageStatsManager .

設備實現:

  • [C-0-1] MUST keep a reasonable retention period of such user history.
  • [SR] Are STRONGLY RECOMMENDED to keep the 14 days retention period as configured by default in the AOSP implementation.

Android stores the system events using the StatsLog identifiers, and manages such history via the StatsManager and the IncidentManager System API.

設備實現:

  • [C-0-2] MUST only include the fields marked with DEST_AUTOMATIC in the incident report created by the System API class IncidentManager .
  • [C-0-3] MUST not use the system event identifiers to log any other event than what is described in the StatsLog SDK documents. If additional system events are logged, they MAY use a different atom identifier in the range between 100,000 and 200,000.

9.8.2.記錄

設備實現:

  • [C-0-1] MUST NOT preload or distribute software components out-of-box that send the user's private information (eg keystrokes, text displayed on the screen, bugreport) off the device without the user's consent or clear ongoing notifications.
  • [C-0-2] MUST display and obtain explicit user consent that includes substantially the same message as AOSP whenever screen casting or screen recording is enabled via MediaProjection or proprietary APIs. MUST NOT provide users an affordance to disable future display of the user consent.

  • [C-0-3] MUST have an ongoing notification to the user while screen casting or screen recording is enabled. AOSP meets this requirement by showing an ongoing notification icon in the status bar.

If device implementations include functionality in the system that either captures the contents displayed on the screen and/or records the audio stream played on the device other than via the System API ContentCaptureService , or Caped Capet, ised , 片面:

  • [C-1-1] MUST have an ongoing notification to the user whenever this functionality is enabled and actively capturing/recording.

If device implementations include a component enabled out-of-box, capable of recording ambient audio and/or record the audio played on the device to infer useful information about user's context, they:

  • [C-2-1] MUST NOT store in persistent on-device storage or transmit off the device the recorded raw audio or any format that can be converted back into the original audio or a near facsimile, except with explicit user consent.

9.8.3。連接性

If device implementations have a USB port with USB peripheral mode support, they:

  • [C-1-1] MUST present a user interface asking for the user's consent before allowing access to the contents of the shared storage over the USB port.

9.8.4. Network Traffic

設備實現:

  • [C-0-1] MUST preinstall the same root certificates for the system-trusted Certificate Authority (CA) store as provided in the upstream Android Open Source Project.
  • [C-0-2] MUST ship with an empty user root CA store.
  • [C-0-3] MUST display a warning to the user indicating the network traffic may be monitored, when a user root CA is added.

If device traffic is routed through a VPN, device implementations:

  • [C-1-1] MUST display a warning to the user indicating either:
    • That network traffic may be monitored.
    • That network traffic is being routed through the specific VPN application providing the VPN.

If device implementations have a mechanism, enabled out-of-box by default, that routes network data traffic through a proxy server or VPN gateway (for example, preloading a VPN service with android.permission.CONTROL_VPN granted), they:

  • [C-2-1] MUST ask for the user's consent before enabling that mechanism, unless that VPN is enabled by the Device Policy Controller via the DevicePolicyManager.setAlwaysOnVpnPackage() , in which case the user does not need to provide a separate consent, but MUST only be notified.

If device implementations implement a user affordance to toggle on the "always-on VPN" function of a 3rd-party VPN app, they:

  • [C-3-1] MUST disable this user affordance for apps that do not support always-on VPN service in the AndroidManifest.xml file via setting the SERVICE_META_DATA_SUPPORTS_ALWAYS_ON attribute to false .

9.8.5。 Device Identifiers

設備實現:

  • [C-0-1] MUST prevent access to the device serial number and, where applicable, IMEI/MEID, SIM serial number, and International Mobile Subscriber Identity (IMSI) from an app, unless it meets one of the following requirements:
    • is a signed carrier app that is verified by device manufacturers.
    • has been granted the READ_PRIVILEGED_PHONE_STATE permission.
    • has carrier privileges as defined in UICC Carrier Privileges .
    • is a device owner or profile owner that has been granted the READ_PHONE_STATE permission.
    • (For SIM serial number/ICCID only) has the local regulations requirement that the app detect changes in the subscriber's identity.

9.8.6。 Content Capture

Android, through the System API ContentCaptureService , or by other proprietary means, supports a mechanism for device implementations to capture the following interactions between the applications and the user.

  • Text and graphics rendered on-screen, including but not limited to, notifications and assist data via AssistStructure API.
  • Media data, such as audio or video, recorded or played by the device.
  • Input events (eg key, mouse, gesture, voice, video, and accessibility).
  • Any other events that an application provides to the system via the Content Capture API or a similarly capable, proprietary API.

If device implementations capture the data above, they:

  • [C-0-1] MUST encrypt all such data when stored in the device. This encryption MAY be carried out using Android File Based Encryption, or any of the ciphers listed as API version 26+ described in Cipher SDK .
  • [C-0-2] MUST NOT back up either raw or encrypted data using Android backup methods or any other back up methods.
  • [C-0-3] MUST only send all such data and the log of the device using a privacy-preserving mechanism. The privacy-preserving mechanism is defined as “those which allow only analysis in aggregate and prevent matching of logged events or derived outcomes to individual users”, to prevent any per-user data being introspectable (eg, implemented using a differential privacy technology such as RAPPOR ).
  • [C-0-4] MUST NOT associate such data with any user identity (such as Account ) on the device, except with explicit user consent each time the data is associated.
  • [C-0-5] MUST NOT share such data with other apps, except with explicit user consent every time it is shared.
  • [C-0-6] MUST provide user affordance to erase such data that the ContentCaptureService or the proprietary means collects if the data is stored in any form on the device.

If device implementations include a service that implements the System API ContentCaptureService , or any proprietary service that captures the data as described as above, they:

  • [C-1-1] MUST NOT allow users to replace the content capture service with a user-installable application or service and MUST only allow the preinstalled service to capture such data.
  • [C-1-2] MUST NOT allow any apps other than the preinstalled content capture service mechanism to be able to capture such data.
  • [C-1-3] MUST provide user affordance to disable the content capture service.
  • [C-1-4] MUST NOT omit user affordance to manage Android permissions that are held by the content capture service and follow Android permissions model as described in Section 9.1.允許
  • [C-SR] Are STRONGLY RECOMMENDED to keep the content capturing service components separate, for example, not binding the service or sharing process IDs, from other system components except for the following:

    • Telephony, Contacts, System UI, and Media

9.8.7。 Clipboard Access

設備實現:

  • [C-0-1] MUST NOT return a clipped data on the clipboard (eg via the ClipboardManager API) unless the app is the default IME or is the app that currently has focus.

9.8.8.地點

設備實現:

  • [C-0-1] MUST NOT turn on/off device location setting and Wi-Fi/Bluetooth scanning settings without explicit user consent or user initiation.
  • [C-0-2] MUST provide the user affordance to access location related information including recent location requests, app level permissions and usage of Wi-Fi/Bluetooth scanning for determining location.
  • [C-0-3] MUST ensure that the application using Emergency Location Bypass API [LocationRequest.setLocationSettingsIgnored()] is a user initiated emergency session (eg dial 911 or text to 911).
  • [C-0-4] MUST preserve the Emergency Location Bypass API's ability to bypass device location settings without changing the settings.
  • [C-0-5] MUST schedule a notification that reminds the user after an app in the background has accessed their location using the [ ACCESS_BACKGROUND_LOCATION ] permission.

9.9.資料儲存加密

All devices MUST meet the requirements of section 9.9.1. Devices which launched on an API level earlier than that of this document are exempted from the requirements of sections 9.9.2 and 9.9.3; instead they MUST meet the requirements in section 9.9 of the Android Compatibility Definition document corresponding to the API level on which the device launched.

9.9.1.直接啟動

設備實現:

  • [C-0-1] MUST implement the Direct Boot mode APIs even if they do not support Storage Encryption.

  • [C-0-2] The ACTION_LOCKED_BOOT_COMPLETED and ACTION_USER_UNLOCKED Intents MUST still be broadcast to signal Direct Boot aware applications that Device Encrypted (DE) and Credential Encrypted (CE) storage locations are available for user.

9.9.2. Encryption requirements

設備實現:

  • [C-0-1] MUST encrypt the application private data ( /data partition), as well as the application shared storage partition ( /sdcard partition) if it is a permanent, non-removable part of the device.
  • [C-0-2] MUST enable the data storage encryption by default at the time the user has completed the out-of-box setup experience.
  • [C-0-3] MUST meet the above data storage encryption requirement via implementing File Based Encryption (FBE).

9.9.3。基於文件的加密

Encrypted devices:

  • [C-1-1] MUST boot up without challenging the user for credentials and allow Direct Boot aware apps to access to the Device Encrypted (DE) storage after the ACTION_LOCKED_BOOT_COMPLETED message is broadcasted.
  • [C-1-2] MUST only allow access to Credential Encrypted (CE) storage after the user has unlocked the device by supplying their credentials (eg. passcode, pin, pattern or fingerprint) and the ACTION_USER_UNLOCKED message is broadcasted.
  • [C-1-3] MUST NOT offer any method to unlock the CE protected storage without either the user-supplied credentials or a registered escrow key.
  • [C-1-4] MUST use Verified Boot and ensure that DE keys are cryptographically bound to the device's hardware root of trust.
  • [C-1-5] MUST encrypt file contents using AES-256-XTS or Adiantum. AES-256-XTS refers to the Advanced Encryption Standard with a 256-bit cipher key length, operated in XTS mode; the full length of the key is 512 bits. Adiantum refers to Adiantum-XChaCha12-AES, as specified at https://github.com/google/adiantum.
  • [C-1-6] MUST encrypt file names using AES-256-CBC-CTS or Adiantum.
  • [C-1-12] MUST use AES-256-XTS for file contents and AES-256-CBC-CTS for file names (instead of Adiantum) if the device has Advanced Encryption Standard (AES) instructions. AES instructions are ARMv8 Cryptography Extensions on ARM-based devices, or AES-NI on x86-based devices. If the device does not have AES instructions, the device MAY use Adiantum.

  • The keys protecting CE and DE storage areas:

  • [C-1-7] MUST be cryptographically bound to a hardware-backed Keystore.

  • [C-1-8] CE keys MUST be bound to a user's lock screen credentials.
  • [C-1-9] CE keys MUST be bound to a default passcode when the user has not specified lock screen credentials.
  • [C-1-10] MUST be unique and distinct, in other words no user's CE or DE key matches any other user's CE or DE keys.
  • [C-1-11] MUST use the mandatorily supported ciphers, key lengths and modes.
  • [C-SR] Are STRONGLY RECOMMENDED to encrypt file system metadata, such as file sizes, ownership, modes, and Extended attributes (xattrs), with a key cryptographically bound to the device's hardware root of trust.

  • SHOULD make preinstalled essential apps (eg Alarm, Phone, Messenger) Direct Boot aware.

The upstream Android Open Source project provides a preferred implementation of this feature based on the Linux kernel "fscrypt" encryption feature.

9.10。設備完整性

The following requirements ensure there is transparency to the status of the device integrity.設備實現:

  • [C-0-1] MUST correctly report through the System API method PersistentDataBlockManager.getFlashLockState() whether their bootloader state permits flashing of the system image. The FLASH_LOCK_UNKNOWN state is reserved for device implementations upgrading from an earlier version of Android where this new system API method did not exist.

  • [C-0-2] MUST support Verified Boot for device integrity.

If device implementations are already launched without supporting Verified Boot on an earlier version of Android and can not add support for this feature with a system software update, they MAY be exempted from the requirement.

Verified Boot is a feature that guarantees the integrity of the device software. If device implementations support the feature, they:

  • [C-1-1] MUST declare the platform feature flag android.software.verified_boot .
  • [C-1-2] MUST perform verification on every boot sequence.
  • [C-1-3] MUST start verification from an immutable hardware key that is the root of trust and go all the way up to the system partition.
  • [C-1-4] MUST implement each stage of verification to check the integrity and authenticity of all the bytes in the next stage before executing the code in the next stage.
  • [C-1-5] MUST use verification algorithms as strong as current recommendations from NIST for hashing algorithms (SHA-256) and public key sizes (RSA-2048).
  • [C-1-6] MUST NOT allow boot to complete when system verification fails, unless the user consents to attempt booting anyway, in which case the data from any non-verified storage blocks MUST not be used.
  • [C-1-7] MUST NOT allow verified partitions on the device to be modified unless the user has explicitly unlocked the bootloader.
  • [C-SR] If there are multiple discrete chips in the device (eg radio, specialized image processor), the boot process of each of those chips is STRONGLY RECOMMENDED to verify every stage upon booting.
  • [C-1-8] MUST use tamper-evident storage: for storing whether the bootloader is unlocked. Tamper-evident storage means that the bootloader can detect if the storage has been tampered with from inside Android.
  • [C-1-9] MUST prompt the user, while using the device, and require physical confirmation before allowing a transition from bootloader locked mode to bootloader unlocked mode.
  • [C-1-10] MUST implement rollback protection for partitions used by Android (eg boot, system partitions) and use tamper-evident storage for storing the metadata used for determining the minimum allowable OS version.
  • [C-SR] Are STRONGLY RECOMMENDED to verify all privileged app APK files with a chain of trust rooted in partitions protected by Verified Boot.
  • [C-SR] Are STRONGLY RECOMMENDED to verify any executable artifacts loaded by a privileged app from outside its APK file (such as dynamically loaded code or compiled code) before executing them or STRONGLY RECOMMENDED not to execute them at all.
  • SHOULD implement rollback protection for any component with persistent firmware (eg modem, camera) and SHOULD use tamper-evident storage for storing the metadata used for determining the minimum allowable version.

If device implementations are already launched without supporting C-1-8 through C-1-10 on an earlier version of Android and can not add support for these requirements with a system software update, they MAY be exempted from the requirements.

The upstream Android Open Source Project provides a preferred implementation of this feature in the external/avb/ repository, which can be integrated into the bootloader used for loading Android.

設備實現:

If device implementations support the Android Protected Confirmation API they:

  • [C-3-1] MUST report true for the ConfirmationPrompt.isSupported() API.

  • [C-3-2] MUST ensure that code running in the Android OS including its kernel, malicious or otherwise, cannot generate a positive response without user interaction.

  • [C-3-3] MUST ensure that the user has been able to review and approve the prompted message even in the event that the Android OS, including its kernel, is compromised.

9.11。金鑰和憑證

The Android Keystore System allows app developers to store cryptographic keys in a container and use them in cryptographic operations through the KeyChain API or the Keystore API .設備實現:

  • [C-0-1] MUST allow at least 8,192 keys to be imported or generated.
  • [C-0-2] The lock screen authentication MUST rate-limit attempts and MUST have an exponential backoff algorithm. Beyond 150 failed attempts, the delay MUST be at least 24 hours per attempt.
  • SHOULD not limit the number of keys that can be generated

When the device implementation supports a secure lock screen, it:

  • [C-1-1] MUST back up the keystore implementation with an isolated execution environment.
  • [C-1-2] MUST have implementations of RSA, AES, ECDSA and HMAC cryptographic algorithms and MD5, SHA1, and SHA-2 family hash functions to properly support the Android Keystore system's supported algorithms in an area that is securely isolated from the code running on the kernel and above. Secure isolation MUST block all potential mechanisms by which kernel or userspace code might access the internal state of the isolated environment, including DMA. The upstream Android Open Source Project (AOSP) meets this requirement by using the Trusty implementation, but another ARM TrustZone-based solution or a third-party reviewed secure implementation of a proper hypervisor-based isolation are alternative options.
  • [C-1-3] MUST perform the lock screen authentication in the isolated execution environment and only when successful, allow the authentication-bound keys to be used. Lock screen credentials MUST be stored in a way that allows only the isolated execution environment to perform lock screen authentication. The upstream Android Open Source Project provides the Gatekeeper Hardware Abstraction Layer (HAL) and Trusty, which can be used to satisfy this requirement.
  • [C-1-4] MUST support key attestation where the attestation signing key is protected by secure hardware and signing is performed in secure hardware. The attestation signing keys MUST be shared across large enough number of devices to prevent the keys from being used as device identifiers. One way of meeting this requirement is to share the same attestation key unless at least 100,000 units of a given SKU are produced. If more than 100,000 units of an SKU are produced, a different key MAY be used for each 100,000 units.

Note that if a device implementation is already launched on an earlier Android version, such a device is exempted from the requirement to have a keystore backed by an isolated execution environment and support the key attestation, unless it declares the android.hardware.fingerprint feature which requires a keystore backed by an isolated execution environment.

  • [C-1-5] MUST allow the user to choose the Sleep timeout for transition from the unlocked to the locked state, with a minimum allowable timeout up to 15 seconds.

9.11.1. Secure Lock Screen and Authentication

The AOSP implementation follows a tiered authentication model where a knowledge-factory based primary authentication can be backed by either a secondary strong biometric, or by weaker tertiary modalities.

設備實現:

  • [C-SR] Are STRONGLY RECOMMENDED to set only one of the following as the primary authentication method:
    • A numeric PIN
    • An alphanumeric password
    • A swipe pattern on a grid of exactly 3x3 dots

Note that the above authentication methods are referred as the recommended primary authentication methods in this document.

If device implementations add or modify the recommended primary authentication methods and use a new authentication method as a secure way to lock the screen, the new authentication method:

If device implementations add or modify the authentication methods to unlock the lock screen if based on a known secret and use a new authentication method to be treated as a secure way to lock the screen:

  • [C-3-1] The entropy of the shortest allowed length of inputs MUST be greater than 10 bits.
  • [C-3-2] The maximum entropy of all possible inputs MUST be greater than 18 bits.
  • [C-3-3] The new authentication method MUST NOT replace any of the recommended primary authentication methods (ie PIN, pattern, password) implemented and provided in AOSP.
  • [C-3-4] The new authentication method MUST be disabled when the Device Policy Controller (DPC) application has set the password quality policy via the DevicePolicyManager.setPasswordQuality() method with a more restrictive quality constant than PASSWORD_QUALITY_SOMETHING .
  • [C-3-5] New authentication methods MUST either fall back to the recommended primary authentication methods (ie PIN, pattern, password) once every 72 hours or less OR clearly disclose to the user that some data will not be backed up in order to preserve the privacy of their data.

If device implementations add or modify the recommended primary authentication methods to unlock the lock screen and use a new authentication method that is based on biometrics to be treated as a secure way to lock the screen, the new method:

  • [C-4-1] MUST meet all requirements described in section 7.3.10 for Convenience .
  • [C-4-2] MUST have a fall-back mechanism to use one of the recommended primary authentication methods which is based on a known secret.
  • [C-4-3] MUST be disabled and only allow the recommended primary authentication to unlock the screen when the Device Policy Controller (DPC) application has set the keyguard feature policy by calling the method DevicePolicyManager.setKeyguardDisabledFeatures() , with any of the associated biometric flags (ie KEYGUARD_DISABLE_BIOMETRICS , KEYGUARD_DISABLE_FINGERPRINT , KEYGUARD_DISABLE_FACE , or KEYGUARD_DISABLE_IRIS ).

If the biometric authentication methods do not meet the requirements for Strong as described in section 7.3.10 :

  • [C-5-1] The methods MUST be disabled if the Device Policy Controller (DPC) application has set the password quality policy via the DevicePolicyManager.setPasswordQuality() method with a more restrictive quality constant than PASSWORD_QUALITY_BIOMETRIC_WEAK .
  • [C-5-2] The user MUST be challenged for the recommended primary authentication (eg: PIN, pattern, password) after any 4-hour idle timeout period. The idle timeout period is reset after any successful confirmation of the device credentials.
  • [C-5-3] The methods MUST NOT be treated as a secure lock screen, and MUST meet the requirements that start with C-8 in this section below.

If device implementations add or modify the authentication methods to unlock the lock screen and a new authentication method is based on a physical token or the location:

  • [C-6-1] They MUST have a fall-back mechanism to use one of the recommended primary authentication methods which is based on a known secret and meet the requirements to be treated as a secure lock screen.
  • [C-6-2] The new method MUST be disabled and only allow one of the recommended primary authentication methods to unlock the screen when the Device Policy Controller (DPC) application has set the policy with either the DevicePolicyManager.setKeyguardDisabledFeatures(KEYGUARD_DISABLE_TRUST_AGENTS) method or the DevicePolicyManager.setPasswordQuality() method with a more restrictive quality constant than PASSWORD_QUALITY_UNSPECIFIED .
  • [C-6-3] The user MUST be challenged for one of the recommended primary authentication methods (egPIN, pattern, password) at least once every 4 hours or less.
  • [C-6-4] The new method MUST NOT be treated as a secure lock screen and MUST follow the constraints listed in C-8 below.

If device implementations have a secure lock screen and include one or more trust agent, which implements the TrustAgentService System API, they:

  • [C-7-1] MUST have clear indication in the settings menu and on the lock screen when device lock is deferred or can be kept unlocked by trust agent(s). For example, AOSP meets this requirement by showing a text description for the "Automatically lock setting" and "Power button instantly locks" in the settings menu and a distinguishable icon on the lock screen.
  • [C-7-2] MUST respect and fully implement all trust agent APIs in the DevicePolicyManager class, such as the KEYGUARD_DISABLE_TRUST_AGENTS constant.
  • [C-7-3] MUST NOT fully implement the TrustAgentService.addEscrowToken() function on a device that is used as a primary personal device (eg handheld) but MAY fully implement the function on device implementations that are typically shared (eg Android Television or Automotive device).
  • [C-7-4] MUST encrypt all stored tokens added by TrustAgentService.addEscrowToken() .
  • [C-7-5] MUST NOT store the encryption key or escrow token on the same device where the key is used. For example, it is allowed for a key stored on a phone to unlock a user account on a TV.
  • [C-7-6] MUST inform the user about the security implications before enabling the escrow token to decrypt the data storage.
  • [C-7-7] MUST have a fall-back mechanism to use one of the recommended primary authentication methods.
  • [C-7-8] The user MUST be challenged for one of the recommended primary authentication (eg: PIN, pattern, password) methods at least once every 72 hours or less unless the safety of the user (cegaction dristraction憂慮。
  • [C-7-9] The user MUST be challenged for one of the recommended primary authentication (eg: PIN, pattern, password) methods after any 4-hour idle timeout period unless the safety of the user (eg driver distraction) is of concern.. The idle timeout period is reset after any successful confirmation of the device credentials.
  • [C-7-10] MUST NOT be treated as a secure lock screen and MUST follow the constraints listed in C-8 below.
  • [C-7-11] MUST NOT allow TrustAgents on primary personal devices (eg: handheld) to unlock the device, and can only use them to keep an already unlocked device in the unlocked state for up to a maximum of 4 hours. The default implementation of TrustManagerService in AOSP meets this requirement.
  • [C-7-12] MUST use a cryptographically secure (eg UKEY2) communication channel to pass the escrow token from the storage device to the target device.

If device implementations add or modify the authentication methods to unlock the lock screen that is not a secure lock screen as described above, and use a new authentication method to unlock the keyguard:

  • [C-8-1] The new method MUST be disabled when the Device Policy Controller (DPC) application has set the password quality policy via the DevicePolicyManager.setPasswordQuality() method with a more restrictive quality constant than PASSWORD_QUALITY_UNSPECIFIED .
  • [C-8-2] They MUST NOT reset the password expiration timers set by DevicePolicyManager.setPasswordExpirationTimeout() .
  • [C-8-3] They MUST NOT expose an API for use by third-party apps to determine the lock state.

9.11.2.保險櫃

The Android Keystore System allows app developers to store cryptographic keys in a dedicated secure processor as well as the isolated execution environment described above. Such a dedicated secure processor is called "StrongBox". Requirements C-1-3 through C-1-11 below define the requirements a device MUST meet to qualify as a StrongBox.

Device implementations that have a dedicated secure processor:

  • [C-SR] Are STRONGLY RECOMMENDED to support StrongBox. StrongBox will likely become a requirement in a future release.

If device implementations support StrongBox, they:

  • [C-1-1] MUST declare FEATURE_STRONGBOX_KEYSTORE .

  • [C-1-2] MUST provide dedicated secure hardware that is used to back keystore and secure user authentication. The dedicated secure hardware may be used for other purposes as well.

  • [C-1-3] MUST have a discrete CPU that shares no cache, DRAM, coprocessors or other core resources with the application processor (AP).

  • [C-1-4] MUST ensure that any peripherals shared with the AP cannot alter StrongBox processing in any way, or obtain any information from the StrongBox. The AP MAY disable or block access to StrongBox.

  • [C-1-5] MUST have an internal clock with reasonable accuracy (+-10%) that is immune to manipulation by the AP.

  • [C-1-6] MUST have a true random number generator that produces uniformly-distributed and unpredictable output.

  • [C-1-7] MUST have tamper resistance, including resistance against physical penetration, and glitching.

  • [C-1-8] MUST have side-channel resistance, including resistance against leaking information via power, timing, electromagnetic radiation, and thermal radiation side channels.

  • [C-1-9] MUST have secure storage which ensures confidentiality, integrity, authenticity, consistency, and freshness of the contents. The storage MUST NOT be able to be read or altered, except as permitted by the StrongBox APIs.

  • To validate compliance with [C-1-3] through [C-1-9], device implementations:

    • [C-1-10] MUST include the hardware that is certified against the Secure IC Protection Profile BSI-CC-PP-0084-2014 or evaluated by a nationally accredited testing laboratory incorporating High attack potential vulnerability assessment according to the Common Criteria Application of Attack Potential to Smartcards .
    • [C-1-11] MUST include the firmware that is evaluated by a nationally accredited testing laboratory incorporating High attack potential vulnerability assessment according to the Common Criteria Application of Attack Potential to Smartcards .
    • [C-SR] Are STRONGLY RECOMMENDED to include the hardware that is evaluated using a Security Target, Evaluation Assurance Level (EAL) 5, augmented by AVA_VAN.5. EAL 5 certification will likely become a requirement in a future release.
  • [C-SR] are STRONGLY RECOMMENDED to provide insider attack resistance (IAR), which means that an insider with access to firmware signing keys cannot produce firmware that causes the StrongBox to leak sadabled, procise 片面tive用戶資料。 The recommended way to implement IAR is to allow firmware updates only when the primary user password is provided via the IAuthSecret HAL.

9.12.資料刪除

All device implementations:

  • [C-0-1] MUST provide users a mechanism to perform a "Factory Data Reset".
  • [C-0-2] MUST delete all data on the userdata filesystem.
  • [C-0-3] MUST delete the data in such a way that will satisfy relevant industry standards such as NIST SP800-88.
  • [C-0-4] MUST trigger the above "Factory Data Reset" process when the DevicePolicyManager.wipeData() API is called by the primary user's Device Policy Controller app.
  • MAY provide a fast data wipe option that conducts only a logical data erase.

9.13。安全啟動模式

Android provides Safe Boot Mode, which allows users to boot up into a mode where only preinstalled system apps are allowed to run and all third-party apps are disabled. This mode, known as "Safe Boot Mode", provides the user the capability to uninstall potentially harmful third-party apps.

Device implementations are:

  • [SR] STRONGLY RECOMMENDED to implement Safe Boot Mode.

If device implementations implement Safe Boot Mode, they:

  • [C-1-1] MUST provide the user an option to enter Safe Boot Mode in such a way that is uninterruptible from third-party apps installed on the device, except when the third-party app is a Device Policy Controller and has set the UserManager.DISALLOW_SAFE_BOOT flag as true.

  • [C-1-2] MUST provide the user the capability to uninstall any third-party apps within Safe Mode.

  • SHOULD provide the user an option to enter Safe Boot Mode from the boot menu using a workflow that is different from that of a normal boot.

9.14。汽車車輛系統隔離

Android Automotive devices are expected to exchange data with critical vehicle subsystems by using the vehicle HAL to send and receive messages over vehicle networks such as CAN bus.

The data exchange can be secured by implementing security features below the Android framework layers to prevent malicious or unintentional interaction with these subsystems.

9.15。訂閱計劃

"Subscription plans" refer to the billing relationship plan details provided by a mobile carrier through SubscriptionManager.setSubscriptionPlans() .

All device implementations:

  • [C-0-1] MUST return subscription plans only to the mobile carrier app that has originally provided them.
  • [C-0-2] MUST NOT remotely back up or upload subscription plans.
  • [C-0-3] MUST only allow overrides, such as SubscriptionManager.setSubscriptionOverrideCongested() , from the mobile carrier app currently providing valid subscription plans.

10.軟體相容性測試

Device implementations MUST pass all tests described in this section. However, note that no software test package is fully comprehensive. For this reason, device implementers are STRONGLY RECOMMENDED to make the minimum number of changes as possible to the reference and preferred implementation of Android available from the Android Open Source Project. This will minimize the risk of introducing bugs that create incompatibilities requiring rework and potential device updates.

10.1.相容性測試套件

設備實現:

  • [C-0-1] MUST pass the Android Compatibility Test Suite (CTS) available from the Android Open Source Project, using the final shipping software on the device.

  • [C-0-2] MUST ensure compatibility in cases of ambiguity in CTS and for any reimplementations of parts of the reference source code.

The CTS is designed to be run on an actual device. Like any software, the CTS may itself contain bugs. The CTS will be versioned independently of this Compatibility Definition, and multiple revisions of the CTS may be released for Android 10.

設備實現:

  • [C-0-3] MUST pass the latest CTS version available at the time the device software is completed.

  • SHOULD use the reference implementation in the Android Open Source tree as much as possible.

10.2. CTS驗證器

The CTS Verifier is included with the Compatibility Test Suite, and is intended to be run by a human operator to test functionality that cannot be tested by an automated system, such as correct functioning of a camera and sensors.

設備實現:

  • [C-0-1] MUST correctly execute all applicable cases in the CTS verifier.

The CTS Verifier has tests for many kinds of hardware, including some hardware that is optional.

設備實現:

  • [C-0-2] MUST pass all tests for hardware that they possess; for instance, if a device possesses an accelerometer, it MUST correctly execute the Accelerometer test case in the CTS Verifier.

Test cases for features noted as optional by this Compatibility Definition Document MAY be skipped or omitted.

  • [C-0-2] Every device and every build MUST correctly run the CTS Verifier, as noted above. However, since many builds are very similar, device implementers are not expected to explicitly run the CTS Verifier on builds that differ only in trivial ways. Specifically, device implementations that differ from an implementation that has passed the CTS Verifier only by the set of included locales, branding, etc. MAY omit the CTS Verifier test.

11. 可更新的軟體

  • [C-0-1] Device implementations MUST include a mechanism to replace the entirety of the system software. The mechanism need not perform “live” upgrades—that is, a device restart MAY be required. Any method can be used, provided that it can replace the entirety of the software preinstalled on the device. For instance, any of the following approaches will satisfy this requirement:

    • “Over-the-air (OTA)” downloads with offline update via reboot.
    • “Tethered” updates over USB from a host PC.
    • “Offline” updates via a reboot and update from a file on removable storage.
  • [C-0-2] The update mechanism used MUST support updates without wiping user data. That is, the update mechanism MUST preserve application private data and application shared data. Note that the upstream Android software includes an update mechanism that satisfies this requirement.

  • [C-0-3] The entire update MUST be signed and the on-device update mechanism MUST verify the update and signature against a public key stored on device.

  • [C-SR] The signing mechanism is STRONGLY RECOMMENDED to hash the update with SHA-256 and validate the hash against the public key using ECDSA NIST P-256.

If the device implementations includes support for an unmetered data connection such as 802.11 or Bluetooth PAN (Personal Area Network) profile, then, they:

  • [C-1-1] MUST support OTA downloads with offline update via reboot.

For device implementations that are launching with Android 6.0 and later, the update mechanism SHOULD support verifying that the system image is binary identical to expected result following an OTA. The block-based OTA implementation in the upstream Android Open Source Project, added since Android 5.1, satisfies this requirement.

Also, device implementations SHOULD support A/B system updates . The AOSP implements this feature using the boot control HAL.

If an error is found in a device implementation after it has been released but within its reasonable product lifetime that is determined in consultation with the Android Compatibility Team to affect the compatibility of third-party applications, then:

  • [C-2-1] The device implementer MUST correct the error via a software update available that can be applied per the mechanism just described.

Android includes features that allow the Device Owner app (if present) to control the installation of system updates. If the system update subsystem for devices report android.software.device_admin then, they:

12. 文件變更日誌

For a summary of changes to the Compatibility Definition in this release:

For a summary of changes to individuals sections:

  1. 介紹
  2. Device Types
  3. 軟體
  4. 應用程式封裝
  5. 多媒體
  6. Developer Tools and Options
  7. 硬體相容性
  8. Performance and Power
  9. Security Model
  10. Software Compatibility Testing
  11. Updatable Software
  12. Document Changelog
  13. 聯絡我們

12.1。變更日誌查看提示

Changes are marked as follows:

  • CDD
    Substantive changes to the compatibility requirements.

  • 文件
    Cosmetic or build related changes.

For best viewing, append the pretty=full and no-merges URL parameters to your changelog URLs.

13. 聯絡我們

You can join the android-compatibility forum and ask for clarifications or bring up any issues that you think the document does not cover.