CODEWITHSUNDEEP
javavideovideo-encodingsteganographylossless
prakhar saxena
prakhar saxena

Reputation: 81

png image files to video (lossless)

For my video steganography project (in java) , I need to encode sequential PNGs into a movie file. I tried xuggler but I was getting compression.(due to which data hidden in the lsb's of the png image is getting lost the next time I extract the frames from the video)

Because I need need to retreive the hidden data later, I need to find a process to encode png images to video(preferred format: avi) in a lossless manner. The size of the new video is not a matter to me.

Hoping if someone could guide me or recommend a useful different java library to do this.

I can post my java code if required.

Upvotes: 0

Views: 3133

Answers (2)

Stanislav Vitvitskyy
Stanislav Vitvitskyy

Reputation: 2377

You can mux a sequence of PNGs into an MP4 file without transcoding ( preserving the exact original images ). To do this in pure Java use JCodec ( http://jcodec.org ): 

public class SequenceMuxer {
    private SeekableByteChannel ch;
    private CompressedTrack outTrack;
    private int frameNo;
    private MP4Muxer muxer;
    private Size size;

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

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

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

    public void encodeImage(File png) throws IOException {
        if (size == null) {
            BufferedImage read = ImageIO.read(png);
            size = new Size(read.getWidth(), read.getHeight());
        }
        // Add packet to video track
        outTrack.addFrame(new MP4Packet(NIOUtils.fetchFrom(png), 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(MP4Muxer.videoSampleEntry("png ", size, "JCodec"));

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

To use it go like this: 

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

Upvotes: 3

Gav
Gav

Reputation: 21

If you download the processing framework, from www.processing.org, you can write a very simple java program to read in your images and write them out to a mov file, if you use the ANIMATION codec and specify lossless, it will be totally lossless.

Upvotes: 2

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