Java Sound API problems

[Gary Richards]

Hi,

I've been using the Java Sound API's to play some audio tracks (Ogg Vorbis and mp3). I've been using the VorbisSPI and MP3SPI from Javazoon.net to support these file formats. I have code sucessfully playing these formats, starting, stopping, pausing resuming. However when I first create my 'Line', it takes around 2-3 seconds for each audio track to play. The code is something like this:

private AudioInputStream currentAudioInputStream;
private SourceDataLine currentLine;
private File dataSource;
 
AudioFileFormat aff = AudioSystem.getAudioFileFormat(dataSource);
AudioInputStream in = AudioSystem.getAudioInputStream(dataSource);
AudioFormat sourceFormat = in.getFormat();
AudioFormat decodedFormat = new AudioFormat(AudioFormat.Encoding.PCM_SIGNED,
            sourceFormat.getSampleRate(),
            16,
            sourceFormat.getChannels(),
            sourceFormat.getChannels() * 2,
            sourceFormat.getSampleRate(),
            false);
AudioInputStream newAudioInputStream = AudioSystem.getAudioInputStream(decodedFormat, in);
 
currentAudioInputStream = newAudioInputStream;
DataLine.Info info = new DataLine.Info(SourceDataLine.class, decodedFormat);
currentLine = (SourceDataLine) AudioSystem.getLine(info);
currentLine.open(decodedFormat);
currentLine.start();

I then have code in a seperate thread which reads in the bytes of audio data and writes them out to the currentLnie, something like this:

byte[] data = new byte[4096 * 4];
while (bytesRead != -1) {
  bytesRead = currentAudioInputStream.read(data, 0,data.length);
  if (bytesRead != -1) {
    bytesWritten = currentLine.write(data, 0, bytesRead);
  }
}

As I have said, by doing this, it takes 2-3 seconds between calling this method and my audio to start playing. I originally thought it to be a problem with my creation of the Thread. So when my object is created it now creates the Thread and starts it. This then sits in a while loop sleeping for 100ms at a time whilst not playing. Yet it still takes 203 seconds before the audio starts to play. If I do the following:

currentLine.drain();
currentLine.stop();

To essentially 'pause' the audio, and then sometime later I do:

currentLine.start();

Which essentially 'resumes' my audio playing again, it resumes instantly.
Therefore the only thing I can put this down to is the time it's taking to create all of the objects to eventually end up with the currentLine object that I use to play that audio.

So... can anyone suggest a way that I can either rewrite this to speed it up, so it plays the audio instantly. Or is there a way I can create a Line or maybe two Line's that I can keep open and use ti play audio instantly each time (if that actually makes sense)?

Ahy help with this is greatly appreciated.

Thanks