我正在尝试寻找流式传输在 Java 应用程序中生成的实时视频的方法。应用程序需要截取自己的屏幕截图并将其编码为视频流并发布流。

到目前为止，我一直在使用 Xuggler (FFMPEG 之上的 Java 库)将屏幕截图编码为视频文件。这很好用。 Xuggler 声称能够通过 RTMP 传输实时视频，但我没有找到任何关于如何以编程方式执行此操作的文档。

1. 有谁知道如何从 Xuggler 以编程方式流式传输 RTMP 视频？
2. 有没有人对我可以用来实现相同结果的其他库有任何建议？我更喜欢通过 RTP 流式传输 MPEG2 格式的视频。

我确实发现有人在 Xuggler 论坛上问了一个非常相似的问题 here没有回应。

我调查了 JMF，但由于其他原因，它不是一个选项。

最佳答案

老实说，不要在 JMF 上浪费时间，您可以认为该产品已死。以下是如何使用 h.264 对 rtmp 流进行屏幕截图(感谢 tyreus@gmail.com 提供的示例)。如果代码没有显示在这里是它的 pastebin: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();
    }
}

关于java - 如何从 Java 应用程序中传输实时视频？，我们在Stack Overflow上找到一个类似的问题： https://stackoverflow.com/questions/3214422/