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.

[ghost]

Having the same issue!

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

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

[ghost]

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;
        }
    }
}