Audio and video sync problem

Question

Hi,
I have a problem with audio and video synchronization. I'm using Merge class to merge video and audio tracks. But audio track can be shorter then whole video track (for example video length: 2 min., audio length 1 min.). When I merge them everything is OK. After that I'd like to concatenate more tracks (generated from merge) into one final video file. For this purpose I'm using Concat class.
But here is the problem, after I concatenate all these tracks then the result video is OK but audio is synchronized right after the previous audio track ended. (If I have video1- 2min. audio1 - 1min., video2 - 2min., audio2 - 30 seconds, then second audio2 starts in 1,30 min right after the first audio track. But I want to start it when the second video2 starts.) Do you have any ideas??
Merge class http://java.sun.com/javase/technologies/desktop/media/jmf/2.1.1/solutions/Merge.html
Concat class http://java.sun.com/javase/technologies/desktop/media/jmf/2.1.1/solutions/Concat.html
Thanks for help in advance.

Answer 1

Ok thanks.
I tried to implement PullBufferDataSource and everything went ok, the audio .wav file was generated, but when I run that file, the length is 0 and not the lenght I wanted (40.00). Where can be a problem?
Here is the code I wrote/changed:
TimeDataSource tds = new TimeDataSource(40.00);
Processor p;
try {
    System.err.println("- create processor for the image datasource ...");
    p = Manager.createProcessor(tds);
} catch (Exception e) {
    System.err.println("Yikes!  Cannot create a processor from the data source.");
    return false;
}I set content type to WAVE:
// Set the output content descriptor to QuickTime.
p.setContentDescriptor(new ContentDescriptor(FileTypeDescriptor.WAVE));I use DataSource as the next:
    class TimeDataSource extends PullBufferDataSource {
                 private double duration;
                 TimeSourceStream streams[];
                 public TimeDataSource(double duration) {
                  this.duration = duration;
                  streams = new TimeSourceStream[1];
              streams[0] = new TimeSourceStream(40);
          @Override
          public PullBufferStream[] getStreams() {
               return streams;
          @Override
          public void connect() throws IOException {
          @Override
          public void disconnect() {
          @Override
          public String getContentType() {
               return ContentDescriptor.RAW;
          @Override
          public Object getControl(String arg0) {
               return null;
          @Override
          public Object[] getControls() {
               return new Object[0];
          @Override
          public Time getDuration() {
               return new Time(duration);
          @Override
          public void start() throws IOException {
          @Override
          public void stop() throws IOException {
    class TimeSourceStream implements PullBufferStream {
               private AudioFormat format;
               private boolean ended = false;
               private long duration;
               public TimeSourceStream(long duration) {
                    this.duration = duration;
                    format = new AudioFormat(AudioFormat.LINEAR, 8000, 8, 1);
          @Override
          public Format getFormat() {
               return format;
          @Override
          public void read(Buffer buf) throws IOException {
               buf.setDuration(duration);
               buf.setFormat(format);
               buf.setEOM(true);
               buf.setOffset(0);
               buf.setLength(0);
               ended = true;     
          @Override
          public boolean willReadBlock() {
               return false;
          @Override
          public boolean endOfStream() {
               return ended;
          @Override
          public ContentDescriptor getContentDescriptor() {
               return new ContentDescriptor(ContentDescriptor.RAW);
          @Override
          public long getContentLength() {
               return 0;
          @Override
          public Object getControl(String arg0) {
               return null;
          @Override
          public Object[] getControls() {
               return new Object[0];
    }Edited by: mako123 on Feb 22, 2010 2:18 PM
Edited by: mako123 on Feb 22, 2010 2:23 PM