Transmitting Audio and Video using RTP

http://java.sun.com/javase/technologies/desktop/media/jmf/2.1.1/solutions/AVTransmit.html

Problem
How to transmit media over the network using JMF and JMF/RTP. You may want to transmit media from one computer to another. Or you may want to broadcast a live feed to your company's intranet. The source of the media can be a file, live media using a capture device or any other source supported by JMF.

Solution
The AVTransmit2 class is similar to VideoTransmit except that it attempts to transmit each of the tracks within the given input media. To do that, an RTP session is created for each media track. For that purpose, the RTP Session API instead of the DataSink API is used for flexibility. For JMF 2.1.1 users, an alternative sample that uses the new RTPManager API is also provided. The default (first available) RTP format is set for each track. For video, special attention is taken to ensure that the input sizes are usable for RTP transmission. Real-time scaling is applied when necessary.

Note that due to limitations of the JMF 2.1 implementation, audio and video are not in tight synchronization.

The AVTransmit2 class takes three parameters in the constructor - the source locator, the destination IP address and a base destination port number for all the media tracks.

The source locator can be -

a file name such as "file:/C:/media/speech.mov",

an http locator such as "http://mediacentral.com/speech.avi",

or a capture datasource such as "javasound://8000"

The IP address should be the IP address of the computer that should receive your transmission. If you want all the computers on your subnet to receive the transmission, then use 255 as the last number in your IP address. For example, "129.130.131.132" can be used for a point to point transmission and "129.130.131.255" can be used for all computers that are on your subnet. Consult your system administrator if you're not sure what these IP addresses mean. You can also refer to the JMF RTP documentation in the JMF Programmer's Guide for more information on RTP transmission and reception.

The base Port number can be any port number that is not in use by any other service on your computer. For example, you can use "22222". Make sure that it is an even number. Once again, refer to the Programmer's Guide. The first media track will be transmitted from the base port number. The next track will go to base port number plus 2 and so on.

The sample program can be used as a utility class as well as standalone. There is a main method that takes three command line parameters. If all goes well, the media will be sent out for 300 seconds and then the application will exit. This 300 seconds limit is because there is no GUI that allows you to specify when to stop the transmission.

Requirements Platform: JDK 1.1.6 or later JMF API: 2.0 or later Implementation: AJ, WPP, SPP * Hardware: [optional] Capture card required for live capture. * AJ = All Java, WPP = Windows Performance Pack, SPP = Solaris Performance Pack

Related Classes

javax.media.Manager javax.media.Processor javax.media.protocol.DataSource javax.media.rtp.SessionManager

How to run this sample

Download and compile the source file. Run AVTransmit2 with the required 3 command line parameters For example, java AVTransmit2 file:/avmedia.mov 129.144.251.182 42050 Or write your own little program that uses the AVTransmit2 class to create, start and stop an RTP transmit session. Since the media tracks are transmitted in multiple sessions, you'll need to use one Player per track on the receive side. Using JMStudio, you can start multiple Players from the "File" menu using the "New Window" item. Then use the "Open URL..." item to open one RTP session per track. The URL to use is: rtp://<sourceIP>:<port>/media Where <sourceIP> is the IP address of the RTP session and the port number is the same one that is used on the transmitting side.

SourceCode：

/*
* @(#)AVTransmit2.java	1.4 01/03/13
*
* Copyright (c) 1999-2001 Sun Microsystems, Inc. All Rights Reserved.
*
* Sun grants you ("Licensee") a non-exclusive, royalty free, license to use,
* modify and redistribute this software in source and binary code form,
* provided that i) this copyright notice and license appear on all copies of
* the software; and ii) Licensee does not utilize the software in a manner
* which is disparaging to Sun.
*
* This software is provided "AS IS," without a warranty of any kind. ALL
* EXPRESS OR IMPLIED CONDITIONS, REPRESENTATIONS AND WARRANTIES, INCLUDING ANY
* IMPLIED WARRANTY OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE OR
* NON-INFRINGEMENT, ARE HEREBY EXCLUDED. SUN AND ITS LICENSORS SHALL NOT BE
* LIABLE FOR ANY DAMAGES SUFFERED BY LICENSEE AS A RESULT OF USING, MODIFYING
* OR DISTRIBUTING THE SOFTWARE OR ITS DERIVATIVES. IN NO EVENT WILL SUN OR ITS
* LICENSORS BE LIABLE FOR ANY LOST REVENUE, PROFIT OR DATA, OR FOR DIRECT,
* INDIRECT, SPECIAL, CONSEQUENTIAL, INCIDENTAL OR PUNITIVE DAMAGES, HOWEVER
* CAUSED AND REGARDLESS OF THE THEORY OF LIABILITY, ARISING OUT OF THE USE OF
* OR INABILITY TO USE SOFTWARE, EVEN IF SUN HAS BEEN ADVISED OF THE
* POSSIBILITY OF SUCH DAMAGES.
*
* This software is not designed or intended for use in on-line control of
* aircraft, air traffic, aircraft navigation or aircraft communications; or in
* the design, construction, operation or maintenance of any nuclear
* facility. Licensee represents and warrants that it will not use or
* redistribute the Software for such purposes.
*/

import java.awt.*;
import java.io.*;
import java.net.InetAddress;
import javax.media.*;
import javax.media.protocol.*;
import javax.media.protocol.DataSource;
import javax.media.format.*;
import javax.media.control.TrackControl;
import javax.media.control.QualityControl;
import javax.media.rtp.*;
import javax.media.rtp.rtcp.*;
import com.sun.media.rtp.*;

public class AVTransmit2 {

// Input MediaLocator
// Can be a file or http or capture source
private MediaLocator locator;
private String ipAddress;
private int portBase;

private Processor processor = null;
private RTPManager rtpMgrs[];
private DataSource dataOutput = null;

public AVTransmit2(MediaLocator locator,
String ipAddress,
String pb,
Format format) {

this.locator = locator;
this.ipAddress = ipAddress;
Integer integer = Integer.valueOf(pb);
if (integer != null)
this.portBase = integer.intValue();
}

/**
* Starts the transmission. Returns null if transmission started ok.
* Otherwise it returns a string with the reason why the setup failed.
*/
public synchronized String start() {
String result;

// Create a processor for the specified media locator
// and program it to output JPEG/RTP
result = createProcessor();
if (result != null)
return result;

// Create an RTP session to transmit the output of the
// processor to the specified IP address and port no.
result = createTransmitter();
if (result != null) {
processor.close();
processor = null;
return result;
}

// Start the transmission
processor.start();

return null;
}

/**
* Stops the transmission if already started
*/
public void stop() {
synchronized (this) {
if (processor != null) {
processor.stop();
processor.close();
processor = null;
for (int i = 0; i < rtpMgrs.length; i++) {
rtpMgrs[i].removeTargets( "Session ended.");
rtpMgrs[i].dispose();
}
}
}
}

private String createProcessor() {
if (locator == null)
return "Locator is null";

DataSource ds;
DataSource clone;

try {
ds = javax.media.Manager.createDataSource(locator);
} catch (Exception e) {
return "Couldn't create DataSource";
}

// Try to create a processor to handle the input media locator
try {
processor = javax.media.Manager.createProcessor(ds);
} catch (NoProcessorException npe) {
return "Couldn't create processor";
} catch (IOException ioe) {
return "IOException creating processor";
}

// Wait for it to configure
boolean result = waitForState(processor, Processor.Configured);
if (result == false)
return "Couldn't configure processor";

// Get the tracks from the processor
TrackControl [] tracks = processor.getTrackControls();

// Do we have atleast one track?
if (tracks == null || tracks.length < 1)
return "Couldn't find tracks in processor";

// Set the output content descriptor to RAW_RTP
// This will limit the supported formats reported from
// Track.getSupportedFormats to only valid RTP formats.
ContentDescriptor cd = new ContentDescriptor(ContentDescriptor.RAW_RTP);
processor.setContentDescriptor(cd);

Format supported[];
Format chosen;
boolean atLeastOneTrack = false;

// Program the tracks.
for (int i = 0; i < tracks.length; i++) {
Format format = tracks[i].getFormat();
if (tracks[i].isEnabled()) {

supported = tracks[i].getSupportedFormats();

// We've set the output content to the RAW_RTP.
// So all the supported formats should work with RTP.
// We'll just pick the first one.

if (supported.length > 0) {
if (supported[0] instanceof VideoFormat) {
// For video formats, we should double check the
// sizes since not all formats work in all sizes.
chosen = checkForVideoSizes(tracks[i].getFormat(),
supported[0]);
} else
chosen = supported[0];
tracks[i].setFormat(chosen);
System.err.println("Track " + i + " is set to transmit as:");
System.err.println("  " + chosen);
atLeastOneTrack = true;
} else
tracks[i].setEnabled(false);
} else
tracks[i].setEnabled(false);
}

if (!atLeastOneTrack)
return "Couldn't set any of the tracks to a valid RTP format";

// Realize the processor. This will internally create a flow
// graph and attempt to create an output datasource for JPEG/RTP
// audio frames.
result = waitForState(processor, Controller.Realized);
if (result == false)
return "Couldn't realize processor";

// Set the JPEG quality to .5.
setJPEGQuality(processor, 0.5f);

// Get the output data source of the processor
dataOutput = processor.getDataOutput();

return null;
}

/**
* Use the RTPManager API to create sessions for each media
* track of the processor.
*/
private String createTransmitter() {

// Cheated.  Should have checked the type.
PushBufferDataSource pbds = (PushBufferDataSource)dataOutput;
PushBufferStream pbss[] = pbds.getStreams();

rtpMgrs = new RTPManager[pbss.length];
SessionAddress localAddr, destAddr;
InetAddress ipAddr;
SendStream sendStream;
int port;
SourceDescription srcDesList[];

for (int i = 0; i < pbss.length; i++) {
try {
rtpMgrs[i] = RTPManager.newInstance();

// The local session address will be created on the
// same port as the the target port. This is necessary
// if you use AVTransmit2 in conjunction with JMStudio.
// JMStudio assumes -  in a unicast session - that the
// transmitter transmits from the same port it is receiving
// on and sends RTCP Receiver Reports back to this port of
// the transmitting host.

port = portBase + 2*i;
ipAddr = InetAddress.getByName(ipAddress);

localAddr = new SessionAddress( InetAddress.getLocalHost(),
port);

destAddr = new SessionAddress( ipAddr, port);

rtpMgrs[i].initialize( localAddr);

rtpMgrs[i].addTarget( destAddr);

System.err.println( "Created RTP session: " + ipAddress + " " + port);

sendStream = rtpMgrs[i].createSendStream(dataOutput, i);
sendStream.start();
} catch (Exception  e) {
return e.getMessage();
}
}

return null;
}

/**
* For JPEG and H263, we know that they only work for particular
* sizes.  So we'll perform extra checking here to make sure they
* are of the right sizes.
*/
Format checkForVideoSizes(Format original, Format supported) {

int width, height;
Dimension size = ((VideoFormat)original).getSize();
Format jpegFmt = new Format(VideoFormat.JPEG_RTP);
Format h263Fmt = new Format(VideoFormat.H263_RTP);

if (supported.matches(jpegFmt)) {
// For JPEG, make sure width and height are divisible by 8.
width = (size.width % 8 == 0 ? size.width :
(int)(size.width / 8) * 8);
height = (size.height % 8 == 0 ? size.height :
(int)(size.height / 8) * 8);
} else if (supported.matches(h263Fmt)) {
// For H.263, we only support some specific sizes.
if (size.width < 128) {
width = 128;
height = 96;
} else if (size.width < 176) {
width = 176;
height = 144;
} else {
width = 352;
height = 288;
}
} else {
// We don't know this particular format.  We'll just
// leave it alone then.
return supported;
}

return (new VideoFormat(null,
new Dimension(width, height),
Format.NOT_SPECIFIED,
null,
Format.NOT_SPECIFIED)).intersects(supported);
}

/**
* Setting the encoding quality to the specified value on the JPEG encoder.
* 0.5 is a good default.
*/
void setJPEGQuality(Player p, float val) {

Control cs[] = p.getControls();
QualityControl qc = null;
VideoFormat jpegFmt = new VideoFormat(VideoFormat.JPEG);

// Loop through the controls to find the Quality control for
// the JPEG encoder.
for (int i = 0; i < cs.length; i++) {

if (cs[i] instanceof QualityControl &&
cs[i] instanceof Owned) {
Object owner = ((Owned)cs[i]).getOwner();

// Check to see if the owner is a Codec.
// Then check for the output format.
if (owner instanceof Codec) {
Format fmts[] = ((Codec)owner).getSupportedOutputFormats(null);
for (int j = 0; j < fmts.length; j++) {
if (fmts[j].matches(jpegFmt)) {
qc = (QualityControl)cs[i];
qc.setQuality(val);
System.err.println("- Setting quality to " +
val + " on " + qc);
break;
}
}
}
if (qc != null)
break;
}
}
}

/****************************************************************
* Convenience methods to handle processor's state changes.
****************************************************************/

private Integer stateLock = new Integer(0);
private boolean failed = false;

Integer getStateLock() {
return stateLock;
}

void setFailed() {
failed = true;
}

private synchronized boolean waitForState(Processor p, int state) {
p.addControllerListener(new StateListener());
failed = false;

// Call the required method on the processor
if (state == Processor.Configured) {
p.configure();
} else if (state == Processor.Realized) {
p.realize();
}

// Wait until we get an event that confirms the
// success of the method, or a failure event.
// See StateListener inner class
while (p.getState() < state && !failed) {
synchronized (getStateLock()) {
try {
getStateLock().wait();
} catch (InterruptedException ie) {
return false;
}
}
}

if (failed)
return false;
else
return true;
}

/****************************************************************
* Inner Classes
****************************************************************/

class StateListener implements ControllerListener {

public void controllerUpdate(ControllerEvent ce) {

// If there was an error during configure or
// realize, the processor will be closed
if (ce instanceof ControllerClosedEvent)
setFailed();

// All controller events, send a notification
// to the waiting thread in waitForState method.
if (ce instanceof ControllerEvent) {
synchronized (getStateLock()) {
getStateLock().notifyAll();
}
}
}
}

/****************************************************************
* Sample Usage for AVTransmit2 class
****************************************************************/

public static void main(String [] args) {
// We need three parameters to do the transmission
// For example,
//   java AVTransmit2 file:/C:/media/test.mov  129.130.131.132 42050

if (args.length < 3) {
prUsage();
}

Format fmt = null;
int i = 0;

// Create a audio transmit object with the specified params.
AVTransmit2 at = new AVTransmit2(new MediaLocator(args[i]),
args[i+1], args[i+2], fmt);
// Start the transmission
String result = at.start();

// result will be non-null if there was an error. The return
// value is a String describing the possible error. Print it.
if (result != null) {
System.err.println("Error : " + result);
System.exit(0);
}

System.err.println("Start transmission for 60 seconds...");

// Transmit for 60 seconds and then close the processor
// This is a safeguard when using a capture data source
// so that the capture device will be properly released
// before quitting.
// The right thing to do would be to have a GUI with a
// "Stop" button that would call stop on AVTransmit2
try {
Thread.currentThread().sleep(60000);
} catch (InterruptedException ie) {
}

// Stop the transmission
at.stop();

System.err.println("...transmission ended.");

System.exit(0);
}

static void prUsage() {
System.err.println("Usage: AVTransmit2 <sourceURL> <destIP> <destPortBase>");
System.err.println("     <sourceURL>: input URL or file name");
System.err.println("     <destIP>: multicast, broadcast or unicast IP address for the transmission");
System.err.println("     <destPortBase>: network port numbers for the transmission.");
System.err.println("                     The first track will use the destPortBase.");
System.err.println("                     The next track will use destPortBase + 2 and so on./n");
System.exit(0);
}
}