To learn more about the use of multi-zone audio in automotive rear-seat entertainment systems, see Multi-Zone Audio.
Device manufacturers can link a display to an audio zone in a vehicle. For instance, for a car with one primary and rear seat entertainment zone, a device manufacturer can have the following configuration on the vendor partition:
<?xml version="1.0" encoding="utf-8"?> <carAudioConfigurations xmlns:car="http://schemas.android.com/apk/res-auto"> <zones> <zone name="primary zone"> <volumeGroups> <group> <device address="bus001_media"> <context context="music"/> </device> <device address="bus002_others"> ... </device> </group> </volumeGroups> <displays> <display car:display="<display-id-1>" /> </displays> </zone> <zone name="rear seat"> <volumeGroups> <group> <device address="bus100_all"> ... </device> </group> </volumeGroups> <displays> <display car:display="<display-id-2>" /> </displays> </zone> </zones> </carAudioConfigurations> </xml>
CarAudioService parses this configuration file and sets up the
audio routing by its audio context (or audio usage) at boot time. During
CarAudioService further detects an app launch event and dynamically
assigns the app to the zone based on UID.
For the stable ID that device manufacturers can include in their configuration file, see Static display identifiers.