我正在按照教程中的代码学习 Xuggler（一个支持 Java 视频流的库），该教程教授如何解码和播放视频。
我认为这段代码是可靠的，但是当我想播放在我的窗口上读取的视频时，我收到错误消息告诉我
Exception in thread "main" java.lang.RuntimeException: got error decoding video in: C:/Users/swnmlab/1.mp4
执行此行时发生此错误
int bytesDecoded = videoCoder.decodeVideo(picture, packet,offset);
我用debugger单步进去发现xuggle-xuggler.jar没有源码附件，有没有人遇到过这个问题？
import java.awt.image.BufferedImage;
import com.xuggle.xuggler.ICodec.Type;
import com.xuggle.xuggler.IContainer;
import com.xuggle.xuggler.IPacket;
import com.xuggle.xuggler.IPixelFormat;
import com.xuggle.xuggler.IStream;
import com.xuggle.xuggler.IStreamCoder;
import com.xuggle.xuggler.IVideoPicture;
import com.xuggle.xuggler.IVideoResampler;
import com.xuggle.xuggler.Utils;
import com.xuggle.xuggler.demos.VideoImage;
public class DecodeAndPlayVideo {
public static void main(String[] args) {
String filename = "C:/Users/swnmlab/1.mp4";
// Create a Xuggler container object
IContainer container = IContainer.make();
// Open up the container
if (container.open(filename, IContainer.Type.READ, null) < 0)
throw new IllegalArgumentException("could not open file: "
+ filename);
// query how many streams the call to open found
int numStreams = container.getNumStreams();
// and iterate through the streams to find the first video stream
int videoStreamId = -1;
IStreamCoder videoCoder = null;
for (int i = 0; i < numStreams; i++) {
// Find the stream object
IStream stream = container.getStream(i);
// Get the pre-configured decoder that can decode this stream;
IStreamCoder coder = stream.getStreamCoder();
if (coder.getCodecType() == Type.CODEC_TYPE_VIDEO) {
videoStreamId = i;
videoCoder = coder;
break;
}
}
if (videoStreamId == -1)
throw new RuntimeException(
"could not find video stream in container: " + filename);
if (videoCoder.acquire() < 0)
throw new RuntimeException(
"could not open video decoder for container: " + filename);
IVideoResampler resampler = null;
if (videoCoder.getPixelType() != IPixelFormat.Type.BGR24) {
// if this stream is not in BGR24, we're going to need to
// convert it. The VideoResampler does that for us.
resampler = IVideoResampler.make(videoCoder.getWidth(),
videoCoder.getHeight(), IPixelFormat.Type.BGR24,
videoCoder.getWidth(), videoCoder.getHeight(),
videoCoder.getPixelType());
if (resampler == null)
throw new RuntimeException("could not create color space "
+ "resampler for: " + filename);
}
/*
* And once we have that, we draw a window on screen
*/
openJavaWindow();
IPacket packet = IPacket.make();
while (container.readNextPacket(packet) >= 0) {
/*
* Now we have a packet, let's see if it belongs to our video stream
*/
if (packet.getStreamIndex() == videoStreamId) {
IVideoPicture picture = IVideoPicture.make(
videoCoder.getPixelType(), videoCoder.getWidth(),
videoCoder.getHeight());
int offset = 0;
while (offset < packet.getSize()) {
/*
* Now, we decode the video, checking for any errors.
*/
int bytesDecoded = videoCoder.decodeVideo(picture, packet,
offset);
if (bytesDecoded < 0)
throw new RuntimeException(
"got error decoding video in: " + filename);
offset += bytesDecoded;
/*
* Some decoders will consume data in a packet, but will not
* be able to construct a full video picture yet. Therefore
* you should always check if you got a complete picture
* from the decoder
*/
if (picture.isComplete()) {
IVideoPicture newPic = picture;
/*
* If the resampler is not null, that means we didn't
* get the video in BGR24 format and need to convert it
* into BGR24 format.
*/
if (resampler != null) {
// we must resample
newPic = IVideoPicture.make(
resampler.getOutputPixelFormat(),
picture.getWidth(), picture.getHeight());
if (resampler.resample(newPic, picture) < 0)
throw new RuntimeException(
"could not resample video from: "
+ filename);
}
if (newPic.getPixelType() != IPixelFormat.Type.BGR24)
throw new RuntimeException("could not decode video"
+ " as BGR 24 bit data in: " + filename);
@SuppressWarnings("deprecation")
BufferedImage javaImage = Utils.videoPictureToImage(newPic);
// and display it on the Java Swing window
updateJavaWindow(javaImage);
}
}
} else {
/*
* This packet isn't part of our video stream, so we just silently drop it.
*/
do {
} while (false);
}
}
closeJavaWindow();
}
private static VideoImage mScreen = null;
private static void updateJavaWindow(BufferedImage javaImage) {
mScreen.setImage(javaImage);
}
private static void openJavaWindow() {
mScreen = new VideoImage();
}
private static void closeJavaWindow() {
System.exit(0);
}
}
PS如果你想尝试这个库，你可以在这里找到安装文件，然后按照这个页面上的步骤在Windows上完成安装这个库。
我发现错误发生是因为我更改了原始代码
if (videoCoder.open() < 0)
throw new RuntimeException(
"could not open video decoder for container: " + filename);
至
if (videoCoder.acquire() < 0)
throw new RuntimeException(
"could not open video decoder for container: " + filename);
由于 open() 方法会导致弃用警告，所以我使用自动完成来找到一个看起来像 open() 的方法，然后更改为 acquire()。我认为这没关系，因为没有“无法打开容器的视频解码器：”异常抛出。所以只需按照示例代码进行操作即可。