Having problem storing incoming MU-LAW to PMC WAV file

Question

Hi,
I am able to receive ULAW/rtp, 8000.0 Hz, 8-bit, Mono stream and play it using the Player class. What I need to do is to store the stream data into WAV file. I have followed the JMF tutorial to set the output file format. I can also create the WAV file no problem. But when I try to play the gnerated WAV file using Windows Media Player, it says : Windows Media Player cannot play the file. The Player might not support the fle type or might not support the codec that was used to compress the file.
Does anyone know what is wrong with my code?
I am attaching the code below:
stream = ((NewReceiveStreamEvent)evt).getReceiveStream();
DataSource ds = stream.getDataSource();
// Find out the formats.
RTPControl ctl = (RTPControl)ds.getControl("javax.media.rtp.RTPControl");
if (ctl != null){
System.err.println(" - Recevied new RTP stream: " + ctl.getFormat());
} else
System.err.println(" - Recevied new RTP stream");
if (participant == null)
System.err.println(" The sender of this stream had yet to be identified.");
else {
System.err.println(" The stream comes from: " + participant.getCNAME());
synchronized (dataSync) {
dataReceived = true;
dataSync.notifyAll();
ProcessorModel model = new ProcessorModel(ds,new Format[]{ }, new FileTypeDescriptor(FileTypeDescriptor.WAVE));
Processor processor = Manager.createRealizedProcessor(model);
boolean result = waitForState(processor, Processor.Configured);
if (result == false)
System.out.println("process is not configured");
TrackControl[] tracks = processor.getTrackControls();
if (tracks == null || tracks.length < 1)
System.out.println( "Couldn't find tracks in processor");
Format supported[];
Format chosen = null;
boolean atLeastOneTrack = false;
for (int i = 0; i < tracks.length; i++)
Format format = tracks.getFormat();
if (tracks[i].isEnabled())
supported = tracks[i].getSupportedFormats();
// Here we choose the ULAW format ...
if (supported.length > 0)
for(int k=0; k<supported.length; k++)
if(supported[k] instanceof AudioFormat)
String encoding = supported[k].getEncoding();
System.out.println("encoding = " + encoding);
if(encoding.indexOf("LINEAR") != -1)
chosen = supported[k];
break;
tracks[i].setFormat(chosen);
//tracks[i].setFormat(new AudioFormat(AudioFormat.LINEAR,8000,16,1));
System.err.println("Track " + i + " is set to transmit as: " + tracks[i].getFormat());
atLeastOneTrack = true;
} else
tracks[i].setEnabled(false);
} else
tracks[i].setEnabled(false);
if (!atLeastOneTrack)
System.out.println( "Couldn't set any of the tracks to a valid RTP format");
// create a player by passing datasource to the Media Manager
result = waitForState(processor, Controller.Realized);
if (result == false)
System.out.println( "Couldn't realize processor");
MediaLocator dest = new MediaLocator("file://c:\\tmp\\dddd.wav");
DataSink sink = Manager.createDataSink(processor.getDataOutput(), dest);
sink.open();
sink.start();
processor.start();
Thread.sleep(5000);
processor.stop();
sink.stop();
sink.close();
System.out.println("sink close");
Thank you very much in advance for all your help.
JB

Answer 1

outraspace wrote:
Hi,
I am able to receive ULAW/rtp, 8000.0 Hz, 8-bit, Mono stream and play it using the Player class. What I need to do is to store the stream data into WAV file. I have followed the JMF tutorial to set the output file format. I can also create the WAV file no problem. But when I try to play the gnerated WAV file using Windows Media Player, it says : Windows Media Player cannot play the file. The Player might not support the fle type or might not support the codec that was used to compress the file.
Does anyone know what is wrong with my code? Lots of things. As tbm pointed out, don't use a processor model. Use create a regular processor, and then create a ContentDescriptor object with all of the formatting you want, and set that on the Processor.
In your code "Here we choose the ULAW format", it doesn't appear that you're chosing ULAW. It appears you're chosing linear encoding. ULaw isn't linear, it's logarithmic, so certainly that's not the right format.
In the examples I've seen, the processor is started before the DataSink is started. You're doing this in reverse.
If you plan to configure a processor, do not get a realized one. That's like say "I'd like some ice cream", going out and buying ice-cream sandwiches and scraping out the ice cream...
You should disable all of the tracks except the ones you want data from. That means if it's not an audio format, you'll want to go ahead and disable it.
Without nitpicking anymore, I have no idea where your sample code came from, but it seems pretty useless. The best idea would be to take your code, delete it, and start over with the following code:
[http://java.sun.com/javase/technologies/desktop/media/jmf/2.1.1/solutions/RTPExport.java]