Can't initialize new AudioTrack instance

[MasterEx]

How to reproduce:

Click the Start/Stop button many times. App crashes.

The exception is thrown on AudioGenerator createPlayer().

The exception is about that:
AudioFlinger could not create track, status: -12
[android.media.AudioTrack ] Error code -20 when initializing AudioTrack.

Not sure why this is happening. My guess is that the AudioTrack binds some resources that later aren't properly released.

Having the same issue!

Not... to worry! Boober Bunz is on the case!

I'm putting up a stackoverflow question on it right now.

Oh wait I didn't realize you are the author of this app. Thanks for making this!!! Did you ever find out why this happens? I'm working on it... I'll definitely let you know if I can figure it out.

[MasterEx]

Hey! No, I haven't figured this out (at least I don't remember doing so 😄 ).

If you fix it, feel free to submit a pull request!

[mgood7123]

How to reproduce:

Click the Start/Stop button many times. App crashes.

The exception is thrown on AudioGenerator createPlayer().

The exception is about that:
AudioFlinger could not create track, status: -12
[android.media.AudioTrack ] Error code -20 when initializing AudioTrack.

Not sure why this is happening. My guess is that the AudioTrack binds some resources that later aren't properly released.

I have had this problem in Oboe

when calling AAudioStream_requestStart(); and AAudioStream_requestStop(); many times rapidly

the cause is a race condition internally

specifically

/*
 * IMPORTANT: avoid starting and stopping the `oboe::AudioStream *stream` rapidly
 * exact reason appears to due to a bug in the AAudio Legacy path for Android P (9),
 *
 * W/AudioStreamLegacy: processCallbackCommon() stopping because callback disabled
 * E/AudioTrack: EVENT_MORE_DATA requested 256 bytes but callback returned -1 bytes
 *
 * see https://github.com/google/oboe/issues/396 :
 *
 * When I returned oboe::DataCallbackResult::Stop in the input stream callback, the callback stopped
 * being called as expected, but the stream state remained in Stopping and never changed to Stopped.
 *
 * In this case, the callback stopped, but the stream state remained in Started with Errors
 * W/AudioStreamLegacy: processCallbackCommon() callback requested stop, fake an error and
 * E/AudioRecord: EVENT_MORE_DATA requested 384 bytes but callback returned -1 bytes
 *
 * And when I tried to restart the stream by calling requestStart(), it didn't work.
 *
 * That is due to a bug in the AAudio Legacy path for Android P (9).
 *
 * This and other bugs related to DataCallbackResult::Stop have been fixed for a future Android
 * release.
*/

the solution to this was

bool STREAM_STARTED = false; // we only use a single stream for now

bool Oboe_Stream_Start() {
    LOGW("Oboe_Init: requesting Start");
    AudioEngine.StartStream();
    LOGW("Oboe_Init: requested Start");
    STREAM_STARTED = true;
    return true;
}

bool Oboe_Stream_Stop() {
    LOGW("Oboe_Init: requesting Stop");
    AudioEngine.StopStream();
    LOGW("Oboe_Init: requested Stop");
    STREAM_STARTED = false;
    return true;
}

NATIVE(void, Oboe, Play)(JNIEnv *env, jobject type) {
    if (currentAudioTrack != NULL) {
        if (!STREAM_STARTED) Oboe_Stream_Start();
        currentAudioTrack->setPlaying(true);
    }
}

NATIVE(void, Oboe, Pause)(JNIEnv *env, jobject type) {
    if (currentAudioTrack != NULL) {
        currentAudioTrack->setPlaying(false);
    }
}

NATIVE(void, Oboe, Stop)(JNIEnv *env, jobject type) {
    if (currentAudioTrack != NULL) {
        if (STREAM_STARTED) Oboe_Stream_Stop();
        currentAudioTrack->setPlaying(false);
        currentAudioTrack->resetPlayHead();
    }
}

in that

when playback is requested, we start our stream ONLY if it has not been started

after that, we simply render our audio

void SoundRecording::renderAudio(int16_t *targetData, uint64_t totalFrames, SoundRecording *Audio){
    SoundRecordingAudioData * AudioData = Audio->AudioData;
    if (mIsPlaying) {

        // Check whether we're about to reach the end of the recording
        if (!mIsLooping && mReadFrameIndex + totalFrames >= mTotalFrames) {
            totalFrames = mTotalFrames - mReadFrameIndex;
            mIsPlaying = false;
        }

        if (mReadFrameIndex == 0) {
            GlobalTime.StartOfFile = true;
            GlobalTime.update(mReadFrameIndex, AudioData);
        }
        for (int i = 0; i < totalFrames; ++i) {
            for (int j = 0; j < AudioData->channelCount; ++j) {
                targetData[(i * AudioData->channelCount) + j] = Audio->Audio[(mReadFrameIndex * AudioData->channelCount) + j];
            }

            // Increment and handle wraparound
            if (++mReadFrameIndex >= mTotalFrames) {
                GlobalTime.EndOfFile = true;
                GlobalTime.update(mReadFrameIndex, AudioData);
                mReadFrameIndex = 0;
            } else {
                GlobalTime.update(mReadFrameIndex, AudioData);
            }
        }
    } else {
        // fill with zeros to output silence
        for (int i = 0; i < totalFrames * AudioData->channelCount; ++i) {
            targetData[i] = 0;
        }
    }
}