问如何在Java环境下解码H.264视频帧

EN

ByteBuffer bb = ... // Your frame data is stored in this buffer
H264Decoder decoder = new H264Decoder();
Picture out = Picture.create(1920, 1088, ColorSpace.YUV_420); // Allocate output frame of max size
Picture real = decoder.decodeFrame(bb, out.getData());
BufferedImage bi = JCodecUtil.toBufferedImage(real); // If you prefere AWT image

int frameNumber = 150;
BufferedImage frame = FrameGrab.getFrame(new File("filename.mp4"), frameNumber);
ImageIO.write(frame, "png", new File("frame_150.png"));

private static void avc2png(String in, String out) throws IOException {
    SeekableByteChannel sink = null;
    SeekableByteChannel source = null;
    try {
        source = readableFileChannel(in);
        sink = writableFileChannel(out);

        MP4Demuxer demux = new MP4Demuxer(source);

        H264Decoder decoder = new H264Decoder();

        Transform transform = new Yuv420pToRgb(0, 0);

        MP4DemuxerTrack inTrack = demux.getVideoTrack();

        VideoSampleEntry ine = (VideoSampleEntry) inTrack.getSampleEntries()[0];
        Picture target1 = Picture.create((ine.getWidth() + 15) & ~0xf, (ine.getHeight() + 15) & ~0xf,
                ColorSpace.YUV420);
        Picture rgb = Picture.create(ine.getWidth(), ine.getHeight(), ColorSpace.RGB);
        ByteBuffer _out = ByteBuffer.allocate(ine.getWidth() * ine.getHeight() * 6);
        BufferedImage bi = new BufferedImage(ine.getWidth(), ine.getHeight(), BufferedImage.TYPE_3BYTE_BGR);
        AvcCBox avcC = Box.as(AvcCBox.class, Box.findFirst(ine, LeafBox.class, "avcC"));

        decoder.addSps(avcC.getSpsList());
        decoder.addPps(avcC.getPpsList());

        Packet inFrame;
        int totalFrames = (int) inTrack.getFrameCount();
        for (int i = 0; (inFrame = inTrack.getFrames(1)) != null; i++) {
            ByteBuffer data = inFrame.getData();

            Picture dec = decoder.decodeFrame(splitMOVPacket(data, avcC), target1.getData());
            transform.transform(dec, rgb);
            _out.clear();

            AWTUtil.toBufferedImage(rgb, bi);
            ImageIO.write(bi, "png", new File(format(out, i)));
            if (i % 100 == 0)
                System.out.println((i * 100 / totalFrames) + "%");
        }
    } finally {
        if (sink != null)
            sink.close();
        if (source != null)
            source.close();
    }
}