用Java编码视频

Question

我正在尝试创建一个屏幕录像机类型的东西,我无法弄清楚如何将多个BufferedImages编码为像mp4这样的可观看格式.我更喜欢纯Java代码,我不能使用最终用户在工作之前必须安装的任何东西.我可以获得我需要的所有音频和帧来弄清楚如何制作视频.

如何使用Java编码带有音频的视频？

Answer 1

您可以使用JCodec(http://jcodec.org)的开源纯Java H.264编解码器.要将BufferedImages序列压缩为MP4文件,请使用以下类:

public class SequenceEncoder {
    private SeekableByteChannel ch;
    private Picture toEncode;
    private RgbToYuv420 transform;
    private H264Encoder encoder;
    private ArrayList<ByteBuffer> spsList;
    private ArrayList<ByteBuffer> ppsList;
    private CompressedTrack outTrack;
    private ByteBuffer _out;
    private int frameNo;
    private MP4Muxer muxer;

    public SequenceEncoder(File out) throws IOException {
        this.ch = NIOUtils.writableFileChannel(out);

        // Transform to convert between RGB and YUV
        transform = new RgbToYuv420(0, 0);

        // Muxer that will store the encoded frames
        muxer = new MP4Muxer(ch, Brand.MP4);

        // Add video track to muxer
        outTrack = muxer.addTrackForCompressed(TrackType.VIDEO, 25);

        // Allocate a buffer big enough to hold output frames
        _out = ByteBuffer.allocate(1920 * 1080 * 6);

        // Create an instance of encoder
        encoder = new H264Encoder();

        // Encoder extra data ( SPS, PPS ) to be stored in a special place of
        // MP4
        spsList = new ArrayList<ByteBuffer>();
        ppsList = new ArrayList<ByteBuffer>();

    }

    public void encodeImage(BufferedImage bi) throws IOException {
        if (toEncode == null) {
            toEncode = Picture.create(bi.getWidth(), bi.getHeight(), ColorSpace.YUV420);
        }

        // Perform conversion
        for (int i = 0; i < 3; i++)
            Arrays.fill(toEncode.getData()[i], 0);
        transform.transform(AWTUtil.fromBufferedImage(bi), toEncode);

        // Encode image into H.264 frame, the result is stored in '_out' buffer
        _out.clear();
        ByteBuffer result = encoder.encodeFrame(_out, toEncode);

        // Based on the frame above form correct MP4 packet
        spsList.clear();
        ppsList.clear();
        H264Utils.encodeMOVPacket(result, spsList, ppsList);

        // Add packet to video track
        outTrack.addFrame(new MP4Packet(result, frameNo, 25, 1, frameNo, true, null, frameNo, 0));

        frameNo++;
    }

    public void finish() throws IOException {
        // Push saved SPS/PPS to a special storage in MP4
        outTrack.addSampleEntry(H264Utils.createMOVSampleEntry(spsList, ppsList));

        // Write MP4 header and finalize recording
        muxer.writeHeader();
        NIOUtils.closeQuietly(ch);
    }
}

然后你可以像这样使用它:

public static void main(String[] args) throws IOException {
    SequenceEncoder encoder = new SequenceEncoder(new File("video.mp4"));
    for (int i = 1; i < 100; i++) {
        BufferedImage bi = ImageIO.read(new File(String.format("img%08d.png", i)));
        encoder.encodeImage(bi);
    }
    encoder.finish();
}