Android Audiotrack Playing .Wav File, Getting Only White Noise

Android AudioTrack playing .wav file, getting only white noise

from your code i can see that you just read data from the wav file and just import them to the AudioTrack. Wav files have a small header as you can see here https://ccrma.stanford.edu/courses/422/projects/WaveFormat/ So you have to skip the header and point your file descriptor at the right place where the actual audio data are.

Also when you playing an audio file and you are dealing with byte operations you should take care of the Endianess. Take a look here Using AudioTrack in Android to play a WAV file

Below my code (some checks and the WAV header skip are missing) that works in both Nexus One and Galaxy S with a wav file with frequency 8000Hz and 16 bit encoding.

public void playWav(){
    int minBufferSize = AudioTrack.getMinBufferSize(8000, AudioFormat.CHANNEL_CONFIGURATION_MONO, AudioFormat.ENCODING_PCM_16BIT);
    int bufferSize = 512;
    AudioTrack at = new AudioTrack(AudioManager.STREAM_MUSIC, 8000, AudioFormat.CHANNEL_CONFIGURATION_MONO, AudioFormat.ENCODING_PCM_16BIT, minBufferSize, AudioTrack.MODE_STREAM);
    String filepath = Environment.getExternalStorageDirectory().getAbsolutePath();

    int i = 0;
    byte[] s = new byte[bufferSize];
    try {
        FileInputStream fin = new FileInputStream(filepath + "/REFERENCE.wav");
        DataInputStream dis = new DataInputStream(fin);

        at.play();
        while((i = dis.read(s, 0, bufferSize)) > -1){
            at.write(s, 0, i);

        }
        at.stop();
        at.release();
        dis.close();
        fin.close();

    } catch (FileNotFoundException e) {
        // TODO
        e.printStackTrace();
    } catch (IOException e) {
        // TODO
        e.printStackTrace();
    }       
}

Using AudioTrack in Android to play a WAV file

I stumbled on the answer (frankly, by trying &^@! I didn't think would work), in case anybody's interested... In my original code (which is derived from the example in the link in the original post), the data is read from the file like so:

    InputStream             is  = new FileInputStream       (file);
    BufferedInputStream     bis = new BufferedInputStream   (is, 8000);
    DataInputStream         dis = new DataInputStream       (bis);      //  Create a DataInputStream to read the audio data from the saved file

    int i = 0;                                                          //  Read the file into the "music" array
    while (dis.available() > 0)
    {
        music[i] = dis.readShort();                                     //  This assignment does not reverse the order
        i++;
    }

    dis.close();                                                        //  Close the input stream

In this version, music[] is array of SHORTS. So, the readShort() method would seem to make sense here, since the data is 16-bit PCM... However, on the Android that seems to be the problem. I changed that code to the following:

     music=new byte[(int) file.length()];//size & length of the file
    InputStream             is  = new FileInputStream       (file);
    BufferedInputStream     bis = new BufferedInputStream   (is, 8000);
    DataInputStream         dis = new DataInputStream       (bis);      //  Create a DataInputStream to read the audio data from the saved file

    int i = 0;                                                          //  Read the file into the "music" array
    while (dis.available() > 0)
    {
        music[i] = dis.readByte();                                      //  This assignment does not reverse the order
        i++;
    }

    dis.close();                                                        //  Close the input stream

In this version, music[] is an array of BYTES. I'm still telling the AudioTrack that it's 16-bit PCM data, and my Android doesn't seem to have a problem with writing an array of bytes into an AudioTrack thus configured... Anyway, it finally sounds right, so if anyone else wants to play Windows sounds on their Android, for some reason, that's the solution. Ah, Endianness......

R.

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