I want to capture and stream audio using JMF 2.1.1e in RTP format. I wrote a simple transmitter, I can transmit and receive the audio. But when I saw in Wireshark, I saw the packets as UDP. Can anyone point me out the problem, please.
And here is my function responsible for audio capture and transmit.
public void captureAudio(){
// Get the device list for ULAW
Vector devices = captureDevices();
CaptureDeviceInfo captureDeviceInfo = null;
if (devices.size() > 0) {
//get the first device from the list and cast it as CaptureDeviceInfo
captureDeviceInfo = (CaptureDeviceInfo) devices.firstElement();
}
else {
// exit if we could not find the relevant capturedevice.
System.out.println("No such device found");
System.exit(-1);
}
Processor processor = null;
try {
//Create a Processor for the specified media.
processor = Manager.createProcessor(captureDeviceInfo.getLocator());
} catch (IOException ex) {
System.err.println(ex);
} catch (NoProcessorException ex) {
System.err.println(ex);
}
//Prepares the Processor to be programmed.
//puts the Processor into the Configuring state.
processor.configure();
//Wait till the Processor configured.
while (processor.getState() != Processor.Configured){
try {
Thread.sleep(100);
} catch (InterruptedException e) {
e.printStackTrace();
}
}
//Sets the output content-type for this Processor
processor.setContentDescriptor(CONTENT_DESCRIPTOR);
/**
ContentDescriptor CONTENT_DESCRIPTOR
= new ContentDescriptor(ContentDescriptor.RAW_RTP);
*/
//Gets a TrackControl for each track in the media stream.
TrackControl track[] = processor.getTrackControls();
boolean encodingOk = false;
//searching through tracks to get a supported audio format track.
for (int i = 0; i < track.length; i++) {
if (!encodingOk && track[i] instanceof FormatControl) {
if (((FormatControl)
track[i]).setFormat( new AudioFormat(AudioFormat.ULAW_RTP, 8000, 8, 1) ) == null)
{
track[i].setEnabled(false);
}
else {
encodingOk = true;
track[i].setEnabled(encodingOk);
System.out.println("enc: " + i);
}
} else {
// we could not set this track to ULAW, so disable it
track[i].setEnabled(false);
}
}
//If we could set this track to ULAW we proceed
if (encodingOk){
processor.realize();
while (processor.getState() != Processor.Realized){
try {
Thread.sleep(100);
} catch (InterruptedException e) {
e.printStackTrace();
}
}
DataSource dataSource = null;
try {
dataSource = processor.getDataOutput();
} catch (NotRealizedError e) {
e.printStackTrace();
}
try {
String url= "rtp://192.168.1.99:49150/audio/1";
MediaLocator m = new MediaLocator(url);
DataSink d = Manager.createDataSink(dataSource, m);
d.open();
d.start();
System.out.println("transmitting...");
processor.start();
} catch (Exception e) {
e.printStackTrace();
}
}
}
And please ask, if you find anything improper or vague. Thanks in advance. :)
Clarification: I have a peice of C# code for RTP streaming. And when I capture the data using wireshark, I can see them as RTP, but the problem is when I capture the data stream from JMF wireshark show them as UDP. And my question is, why?
I know the difference between UDP and RTP.
