Tarsos dsp Android AudioTrack播放静态或速度过快

Question

This problem has been frustrating me for a while. I'm trying to use Tarsos DSP to perform some basic signal processing on a project I'm working on for Android. The audio comes from a standard WAV file that is 44.1k, 16bit stereo. When I set up and run a Tarsos AudioDispatcher using an AudioProcessor that uses Android's AudioTrack to output sound I get static or audio that plays way too fast.

Here is the code that sets up the Audio Dispatcher

public void Play(String source, double startTime, final double endTime){
    InputStream wavStream;
    try {
        wavStream = new FileInputStream(source);
        UniversalAudioInputStream audioStream = new UniversalAudioInputStream(wavStream, audioFormat); 
        dispatcher = new AudioDispatcher(audioStream, bufferSize, overLap);
        AndroidAudioPlayer player = new AndroidAudioPlayer(audioFormat, buffersize);
        dispatcher.addAudioProcessor(player);
        dispatcher.skip(startTime);
        new Thread(new Runnable() {
            @Override
            public void run() {
                while (dispatcher.secondsProcessed() < endTime) {
                    try {
                        Thread.sleep(10);
                    } catch (InterruptedException e) {
                        e.printStackTrace();
                    }
                }
                dispatcher.stop();
            }
        }).start();
        dispatcher.run();
        try {
            audioStream.close();
        } catch (IOException e) {
            e.printStackTrace();
        }
    }catch (FileNotFoundException e){e.printStackTrace();}
}

One thing that I've noted is that if I let the AudioDispatcher run through the entire WAV file it reports a total number of seconds processed that is longer than what is indicated in the header of the WAV file which makes the methods that set the start and end times inaccurate but still within bounds (usually). (Why does this happen?)**

Here is the code for the AndroidAudioPlayer that implements a Tarsos AudioProcessor:

public class AndroidAudioPlayer implements AudioProcessor {
private AudioTrack audioTrack;
AndroidAudioPlayer(TarsosDSPAudioFormat audioFormat, int bufferSize){
    audioTrack = new AudioTrack(AudioManager.STREAM_MUSIC,
            (int)audioFormat.getSampleRate(),
            AudioFormat.CHANNEL_OUT_STEREO,
            AudioFormat.ENCODING_PCM_16BIT,
            bufferSize,
            AudioTrack.MODE_STREAM);
}
@Override
public boolean process(AudioEvent audioEvent){
    short[] shorts = new short[audioEvent.getBufferSize() / 2];
    ByteBuffer.wrap(audioEvent.getByteBuffer()).order(ByteOrder.LITTLE_ENDIAN).asShortBuffer().get(shorts);
    audioTrack.write(shorts, 0, shorts.length);
    audioTrack.play();
    return true;
}

@Override
public void processingFinished(){}

}

I have another audio processor that I wrote that uses an AudioDispatcher to write a clip from the WAV file using JavaZoom which also produces static or incorrect audio. However, when I write a clip from the WAV file using an InputStream and JavaZoom it works fine some of the time or produces static which I am assuming is because the startTime and stopTime variables are set incorrectly by my methods that rely on Tarsos. Any insight would be greatly appreciated.

Before the methods above are called, I initially call a method that uses AudioDispatcher on the same WAV file with Oscilloscope and ComplexOnsetDetector audio processors to generate a waveform view and fill an array with timecodes for onsets. The audioFormat variable is created like this: TarsosDSPAudioFormat audioFormat = new TarsosDSPAudioFormat(sampleRate, 16, 2, false, false); , the sample rate is read from the WAV file and I've checked that it reads correctly. *The buffer size is 1024 and overlap is 512 and I've tried playing with all of these values.

I have changed the buffer size to 64kb and the overlap to 32kb. When the audio plays, it sounds almost correct, skipping a little bit. However, it still sometimes only plays static and no matter what length of WAV file I use, the AudioDispatcher reports that it was 315 seconds long* .

**I have fixed this problem. I was loading a WAV file that was being created by JavaZoom MP3 converter which was continually overwriting a file without deleting it first. I think Tarsos was using the file length to determine the play length which was incorrect due to the overwriting with out deletion. Deleting the file first solved the problem.

I just need to figure out why the audio is skipping during playback and sometimes just plays static and then I think I'm good to go.

Answer 1

Use mono(1 channel) input. TarsosDSP audio processors does not support stereo currently.