What is needed and when
Android <= 8:
- for voice calls: AudioFlinger
- for media (camera etc): AudioFlinger (o)
Android >= 9:
- for voice calls: IQcRilAudio
- for media (camera etc): AudioFlinger (o)
All? Android versions:
- for media (camera etc): AudioFlinger (o)
(o): Depends, that is, some devices might not need this but others do.
For voice calls, one of
- combination of pulseaudio-modules-droid-glue and audioflingerglue
- combination of pulseaudio-modules-droid-hidl and audiosystem-passthrough
For media, one of
- audioflingerglue
- audiosystem-passthrough-dummy-af (from package audiosystem-passthrough)
If device needs AudioFlinger for both voice calls and media and a combination of pa-modules-droid-hidl and audiosystem-passthrough is used a single instance of audiosystem-passthrough running under pulseaudio-modules-droid-hidl is enough.
For voice calls,
- combination of pulseaudio-modules-droid-hidl and audiosystem-passthrough
When run from the droid-hidl module the module tries to autodetect correct configuration for the helper. If this is not the case you can modify PulseAudio sysconfig file (/etc/sysconfig/pulseaudio) and add following environment variables:
AUDIOSYSTEM_PASSTHROUGH_TYPE={qti,af}
AUDIOSYSTEM_PASSTHROUGH_IDX={17,18} # only applicable to af type
Type qti is for devices which have qti HIDL interface IQcRilAudio.
Package audiosystem-passthrough-dummy-af contain service file which starts audiosystem-passthrough in AudioFlinger dummy mode. This can be used on devices where AudioFlinger service needs to be present but isn't used for anything.