When building a radio app, we recommend you use the
HwAudioSource as it creates the patch as well as
a media session to handle media key events. Multiple audio sources can be created
for the same source and audio attributes. It's possible to have one for regular
radio usage and a second for traffic announcements.
If recording the FM_TUNER, in Android 11 the permission for doing so
was changed to android.permission.CAPTURE_AUDIO_OUTPUT. It
no longer performs an OP_RECORD_AUDIO permission check, which applies
to microphones only. This has no impact on apps as FM_TUNER already required
the SYSTEM_API permission to access.
See Implement Radio for more details on building a radio app.