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jcodec - a pure java implementation of video/audio codecs.


JCodec is a library implementing a set of popular video and audio codecs. Currently JCodec supports:

  • Video codecs

    • H.264 main profile decoder;
    • H.264 baseline profile encoder;
    • VP8 decoder (I frames only);
    • VP8 encoder (I frames only);
    • MPEG 1/2 decoder ( I/P/B frames, interlace );
    • Apple ProRes decoder/encoder;
    • JPEG decoder;
    • PNG decoder/encoder.
    • DivX/Xvid
  • Audio codecs

    • SMPTE 302M decoder;
    • AAC decoder (JAAD)
    • RAW PCM.
  • Formats:

    • MP4 ( MOV ) demuxer / muxer;
    • MKV ( Matroska ) demuxer / muxer;
    • MPEG PS demuxer;
    • MPEG TS demuxer;
    • WAV demuxer/muxer;
    • MPEG Audio (MP3) demuxer;
    • ADTS demuxer.
    • DPX parser

JCodec is free software distributed under FreeBSD License.

Future development

Those are just some of the things JCodec dev team is planning to work on:

  • Video
    • Improve H.264 encoder: CABAC, rate control;
    • Performance optimize H.264 decoder.
  • Audio
    • MP3 decoder;
    • AAC encoder.

Getting started

JCodec can be used in both standard Java and Android. It contains platform-agnostic java classes. To use the latest version of JCodec add the maven dependency as below:


OR gradle dependency as below:

dependencies {
    implementation 'org.jcodec:jcodec:0.2.5'

Additionally if you want to use JCodec with AWT images (BufferedImage) add this maven dependency:


OR if you want to use JCodec with Android images (Bitmap) add this gradle dependency:

android {
    configurations.all {
        resolutionStrategy.force ''
dependencies {
    implementation 'org.jcodec:jcodec:0.2.5'
    implementation 'org.jcodec:jcodec-android:0.2.5'

For the latest and greatest (the 0.2.6-SNAPSHOT) clone this Git project and build locally like so:

git clone
cd jcodec
mvn clean install
(cd javase; mvn clean install)
(cd android; mvn clean install)

If you JUST need the jars, download them from here:

There is virtually no documentation right now but the plan is to catch up on this so stay tuned. contains quite a bit information at this point.

Also check the 'samples' subfolder. It's a maven project, and it contains some code samples for the popular use-cases:

Performance / quality considerations

Because JCodec is a pure Java implementation please adjust your performance expectations accordingly. We usually make the best effort to write efficient code but despite this the decoding will typically be an order of magnitude slower than the native implementations (such as FFMpeg). We are currently looking into implementing performance-critical parts in OpenCL (or RenderScript for Android) but the ETA is unknown.

Expect the encoded quality/bitrate for h.264 (AVC) to be so much worse compared to the well known native encoders (such as x264). This is because very little work has been put so far into developing the encoder and also because encoders usually trade speed for quality, speed is something we don't have in Java, hence the quality. Again we may potentially fix that in the future by introducing OpenCL (RenderScript) code but at this point it's an unknown.

That said the decode quality should be at the industry level. This is because the decoding process is usually specified by the standard and the correct decoder implementations are expected to produce bit-exact outputs.

Sample code

Getting a single frame from a movie ( supports only AVC, H.264 in MP4, ISO BMF, Quicktime container ):

int frameNumber = 42;
Picture picture = FrameGrab.getFrameFromFile(new File("video.mp4"), frameNumber);

//for JDK (jcodec-javase)
BufferedImage bufferedImage = AWTUtil.toBufferedImage(picture);
ImageIO.write(bufferedImage, "png", new File("frame42.png"));

//for Android (jcodec-android)
Bitmap bitmap = AndroidUtil.toBitmap(picture);
bitmap.compress(Bitmap.CompressFormat.PNG, 100, new FileOutputStream("frame42.png")); 

Get all frames from a video file

File file = new File("video.mp4");
FrameGrab grab = FrameGrab.createFrameGrab(NIOUtils.readableChannel(file));
Picture picture;
while (null != (picture = grab.getNativeFrame())) {
    System.out.println(picture.getWidth() + "x" + picture.getHeight() + " " + picture.getColor());

Getting a sequence of frames from a movie ( supports only AVC, H.264 in MP4, ISO BMF, Quicktime container ):

double startSec = 51.632;
int frameCount = 10;
File file = new File("video.mp4");

FrameGrab grab = FrameGrab.createFrameGrab(NIOUtils.readableChannel(file));

for (int i=0;i<frameCount;i++) {
    Picture picture = grab.getNativeFrame();
    System.out.println(picture.getWidth() + "x" + picture.getHeight() + " " + picture.getColor());
    //for JDK (jcodec-javase)
    BufferedImage bufferedImage = AWTUtil.toBufferedImage(picture);
    ImageIO.write(bufferedImage, "png", new File("frame"+i+".png"));

    //for Android (jcodec-android)
    Bitmap bitmap = AndroidUtil.toBitmap(picture);
    bitmap.compress(Bitmap.CompressFormat.PNG, 100, new FileOutputStream("frame"+i+".png")); 

Making a video with a set of images from memory:

SeekableByteChannel out = null;
try {
    out = NIOUtils.writableFileChannel("/tmp/output.mp4");
    // for Android use: AndroidSequenceEncoder
    AWTSequenceEncoder encoder = new AWTSequenceEncoder(out, Rational.R(25, 1));
    for (...) {
        // Generate the image, for Android use Bitmap
        BufferedImage image = ...;
        // Encode the image
    // Finalize the encoding, i.e. clear the buffers, write the header, etc.
} finally {

H264 video from png images

File output = new File("test.mp4");
SequenceEncoder enc = SequenceEncoder.createWithFps(NIOUtils.writableChannel(output), new Rational(1, 1));
String[] files = {"frame0.png", "frame1.png", "frame2.png"};
for (String file : files) {
   enc.encodeNativeFrame(AWTUtil.decodePNG(new File(file), ColorSpace.RGB));

Read Tape Timecode from MXF file

TapeTimecode timecode = MXFDemuxer.readTapeTimecode(new File("myfile.mxf"));

Parse DPX metadata

DPXMetadata dpx = DPXReader.readFile(firstDpx).parseMetadata();

Parse Apple GPS metadata from MOV or MP4 file

MovieBox moov = MP4Util.parseMovie(new File("gps1.mp4"));
UdtaBox udta = NodeBox.findFirst(moov, UdtaBox.class, "udta");
String latlng = udta.latlng();
assertEquals("-35.2840+149.1215/", latlng);


MovieBox moov = MP4Util.parseMovie(new File("gps2.MOV"));
MetaBox meta = NodeBox.findFirst(moov, MetaBox.class, "meta");
String latlng1 = meta.getKeyedMeta().get("").getString();
assertEquals("-35.2844+149.1214+573.764/", latlng1);
String latlng2 = meta.getItunesMeta().get(1).getString();
assertEquals("-35.2844+149.1214+573.764/", latlng2);

Extract subtitles from MKV file

MKVDemuxer demuxer = new MKVDemuxer(new AutoFileChannelWrapper(new File("subs.mkv")));
DemuxerTrack track = demuxer.getSubtitleTracks().get(0);
Packet packet;
while (null != (packet = track.nextFrame())) {
    String text = takeString(packet.getData());
    System.out.println("time: " + packet.pts + " text: " + text);

MP4/M4A/MOV metadata versions

Some editors (e.g. Final Cut Pro 7) employ a clever hack to support multiple versions of metadata for mp4 files. The trick is to append a new version of moov atom to end of file and set previous version atom name to free. Jcodec supports this hack via org.jcodec.movtool.MoovVersions

See for complete usage example.

To list available versions use

MoovVersions.listMoovVersionAtoms(new File("my.mp4"))

To add a version

moov = MP4Util.parseMovie(new File("my.mp4"))
//add your modifications to moov here
MoovVersions.addVersion(new File("my.mp4"), moov)

To rollback (undo) to previous version

MoovVersions.undo(new File("my.mp4"))

To rollback to specific version

versions = MoovVersions.listMoovVersionAtoms(new File("my.mp4"))
//pick your version
version = versions.get(Math.random()*versions.size())
MoovVersions.rollback(new File("my.mp4"), version)


Feel free to communicate any questions or concerns to us. Dev team email: