AudioStreamOpenSLES::processBufferCallback returns SL_RESULT_INTERNAL_ERROR

[philburk]

It does this in order to stop the stream if the callback requests a stop, in other words if the return from the callback is != DataCallbackResult::Continue.

Don suggested we could use the SL player interface to set the play state to stopped. E.g.

/~https://github.com/googlesamples/android-ndk/blob/master/audio-echo/app/src/main/cpp/audio_player.cpp#L235

Additionally, we could set the stream state to stopped.

We need to test and verify that it is safe to stop an OpenSL ES stream from a callback.

[philburk]

Fixed by #323