IssueTracker

It can be useful for audio subsystem components, such as audio effects and encoders integrated beneath the audio HAL, to be notified of the encoding of the audio data prior to its decoding to PCM and writing to AudioTrack, so that its behavior can be modified. For example, an encoder integrated beneath an audio HAL may encode different metadata into its bitstream depending on the original encoding (prior to decoding to PCM) of the playing audio.

To support this, add an API to AudioTrack (and later AAudio similarly) that is passed to the audio server and then forwarded to the audio HAL via playback track metadata.