jcodec - has anyone seen documentation on this library?

Question

I'm trying to use jcodec to encode bufferedimages into a h264 movie. Only I haven't been able to find example code anywhere.

Has anyone used this library in the past? I haven't seen any documentation, even the javadoc that comes with the library contains no usage information. If you have seen examples, or can provide insight please let me know.

http://jcodec.org/

Thanks in advance

there is no documentation, therefore this library is worthless.... — rockit, Jun 13 '12 at 00:52
There is definitely lot of work gone into this library but because of lack of documentation, it's hard to utilize it. I have been trying to figure out how to trim (seek, duration) a HTTP streamed mp4 container but have not been successful yet. — Rajiv, Jun 20 '13 at 18:59

score 4 · Accepted Answer · edited May 23 '17 at 11:56

JCodec does not support encoding of H.264. You can however use JNA with x264 library or ffmpeg. If you choose this route this thread may help you to get going: How does one encode a series of images into H264 using the x264 C API? .

[UPDATE] As of version 0.1.0 JCodec supports H.264 encoding, here's a simple class that you can use to turn your sequence of images into an H.264 video in MP4 container:

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);
    }

    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("folder/img%08d.png", i)));
            encoder.encodeImage(bi);
        }
        encoder.finish();
    }
}

[UPDATE 1] Use this code to convert from interleaved YUV 4:2:0 byte array to JCodec picture:

byte[] input = ...
Picture output = Picture.create(width, height, ColorSpace.YUV420);
int[] d0 = output.getData()[0], d1 = output.getData()[1], d2 = output.getData()[2];

for(int i = 0, j0 = 0, j1 = 0, j2 = 0; i < input.length; i += 6, j0 += 4, ++j1 , ++j2) {
    d0[j0    ] = input[i    ] & 0xff;
    d0[j0 + 1] = input[i + 1] & 0xff;
    d0[j0 + 2] = input[i + 2] & 0xff;
    d0[j0 + 3] = input[i + 3] & 0xff;

    d1[j1    ] = input[i + 4] & 0xff;
    d2[j2    ] = input[i + 5] & 0xff;
}

a question, but if I have already a yuv420sp byte[] array, how do I convert this to the jcodec Picture object? — PerracoLabs, May 28 '13 at 21:15
If this version of Jcodec supports encoding h264, may I generate "video.h264" ? I have to use h264 with mp4parser library to add audio to the video but mp4parser needs h264 for input. Can you help me? Thanks — Ehsan, Sep 06 '14 at 12:26

jcodec - has anyone seen documentation on this library?

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