问题
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.
- Does anyone know how to stream RTMP video programmatically from Xuggler?
- 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.
回答1:
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 tyreus@gmail.com 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();
}
}
来源：https://stackoverflow.com/questions/3214422/how-to-transmit-live-video-from-within-a-java-application