How to transmit live video from within a Java application?

Tansir1 picture Tansir1 · Jul 9, 2010 · Viewed 18.2k times · Source

I'm trying to find ways to stream a live video generated in a Java application. The application needs to take screenshots of itself and encode these into a video stream and publish the stream.

So far I have been using Xuggler (a Java library on top of FFMPEG) to encode the screenshots into a video file. This works great. Xuggler claims to be able to transmit live video via RTMP but I have not found any documentation on how to do this programmatically.

  1. Does anyone know how to stream RTMP video programmatically from Xuggler?
  2. Does anyone have a suggestion on other libraries I could use to achieve the same results? I'd prefer to stream the video in MPEG2 over RTP.

I did find someone else asking a very similar question on the Xuggler forums here with no response.

I have looked into JMF and it is not an option for other reasons.

Answer

Paul Gregoire picture Paul Gregoire · Aug 31, 2010

Honestly don't waste your time with JMF, you can consider that offering dead. Here is how you would do screen shotting to an rtmp stream using h.264 (thanks to [email protected] for the example). If the code doesn't show up here's pastebin for it: http://pastebin.com/sJHwj0nW

import com.xuggle.xuggler.Configuration;
import com.xuggle.xuggler.ICodec;
import com.xuggle.xuggler.IContainer;
import com.xuggle.xuggler.IContainerFormat;
import com.xuggle.xuggler.IPacket;
import com.xuggle.xuggler.IPixelFormat;
import com.xuggle.xuggler.IRational;
import com.xuggle.xuggler.IStream;
import com.xuggle.xuggler.IStreamCoder;
import com.xuggle.xuggler.IVideoPicture;
import com.xuggle.xuggler.video.ConverterFactory;
import com.xuggle.xuggler.video.IConverter;
import java.awt.AWTException;
import java.awt.Rectangle;
import java.awt.Robot;
import java.awt.image.BufferedImage;
import java.io.IOException;
import java.io.InputStream;
import java.util.Properties;

public class XugglerRtmpReferenceImpl {

   private static String url = "rtmp://your.test.server/screen/";
   private static String fileName = "test/teststream";
   private static int framesToEncode = 60;
   private static int x = 0;
   private static int y = 0;
   private static int height = 480;
   private static int width = 640;

   public static void main(String[] args) {
       IContainer container = IContainer.make();
       IContainerFormat containerFormat_live = IContainerFormat.make();
       containerFormat_live.setOutputFormat("flv", url + fileName, null);
       container.setInputBufferLength(0);
       int retVal = container.open(url + fileName, IContainer.Type.WRITE, containerFormat_live);
       if (retVal < 0) {
           System.err.println("Could not open output container for live stream");
           System.exit(1);
       }
       IStream stream = container.addNewStream(0);
       IStreamCoder coder = stream.getStreamCoder();
       ICodec codec = ICodec.findEncodingCodec(ICodec.ID.CODEC_ID_H264);
       coder.setNumPicturesInGroupOfPictures(5);
       coder.setCodec(codec);
       coder.setBitRate(200000);
       coder.setPixelType(IPixelFormat.Type.YUV420P);
       coder.setHeight(height);
       coder.setWidth(width);
       System.out.println("[ENCODER] video size is " + width + "x" + height);
       coder.setFlag(IStreamCoder.Flags.FLAG_QSCALE, true);
       coder.setGlobalQuality(0);
       IRational frameRate = IRational.make(5, 1);
       coder.setFrameRate(frameRate);
       coder.setTimeBase(IRational.make(frameRate.getDenominator(), frameRate.getNumerator()));
       Properties props = new Properties();
       InputStream is = XugglerRtmpReferenceImpl.class.getResourceAsStream("/libx264-normal.ffpreset");
       try {
           props.load(is);
       } catch (IOException e) {
           System.err.println("You need the libx264-normal.ffpreset file from the Xuggle distribution in your classpath.");
           System.exit(1);
       }
       Configuration.configure(props, coder);
       coder.open();
       container.writeHeader();
       long firstTimeStamp = System.currentTimeMillis();
       long lastTimeStamp = -1;
       int i = 0;
       try {
           Robot robot = new Robot();
           while (i < framesToEncode) {
               //long iterationStartTime = System.currentTimeMillis();
               long now = System.currentTimeMillis();
               //grab the screenshot
               BufferedImage image = robot.createScreenCapture(new Rectangle(x, y, width, height));
               //convert it for Xuggler
               BufferedImage currentScreenshot = new BufferedImage(image.getWidth(), image.getHeight(), BufferedImage.TYPE_3BYTE_BGR);
               currentScreenshot.getGraphics().drawImage(image, 0, 0, null);
               //start the encoding process
               IPacket packet = IPacket.make();
               IConverter converter = ConverterFactory.createConverter(currentScreenshot, IPixelFormat.Type.YUV420P);
               long timeStamp = (now - firstTimeStamp) * 1000; 
               IVideoPicture outFrame = converter.toPicture(currentScreenshot, timeStamp);
               if (i == 0) {
                   //make first frame keyframe
                   outFrame.setKeyFrame(true);
               }
               outFrame.setQuality(0);
               coder.encodeVideo(packet, outFrame, 0);
               outFrame.delete();
               if (packet.isComplete()) {
                   container.writePacket(packet);
                   System.out.println("[ENCODER] writing packet of size " + packet.getSize() + " for elapsed time " + ((timeStamp - lastTimeStamp) / 1000));
                   lastTimeStamp = timeStamp;
               }
               System.out.println("[ENCODER] encoded image " + i + " in " + (System.currentTimeMillis() - now));
               i++;
               try {
                   Thread.sleep(Math.max((long) (1000 / frameRate.getDouble()) - (System.currentTimeMillis() - now), 0));
               } catch (InterruptedException e) {
                   e.printStackTrace();
               }
           }
       } catch (AWTException e) {
           e.printStackTrace();
       }
       container.writeTrailer();
    }
}