ImageToH264MP4Encoder.java

package info.guardianproject.iocipher.camera.encoders;

import java.io.IOException;
import java.nio.ByteBuffer;
import java.util.ArrayList;

import org.jcodec.codecs.h264.H264Encoder; 

import org.jcodec.codecs.h264.H264Utils;
import org.jcodec.common.AudioFormat;
import org.jcodec.common.NIOUtils;
import org.jcodec.common.SeekableByteChannel;
import org.jcodec.common.model.ColorSpace;
import org.jcodec.common.model.Picture;
import org.jcodec.containers.mp4.Brand;
import org.jcodec.containers.mp4.MP4Packet;
import org.jcodec.containers.mp4.TrackType;
import org.jcodec.containers.mp4.muxer.FramesMP4MuxerTrack;
import org.jcodec.containers.mp4.muxer.MP4Muxer;
import org.jcodec.containers.mp4.muxer.PCMMP4MuxerTrack;
import org.jcodec.scale.ColorUtil;
import org.jcodec.scale.Transform;


/**
 * 
 * This file contains code from the IOCipher Camera Library "CipherCam".
 *
 * For more information about IOCipher, see https://guardianproject.info/code/iocipher
 * and this sample library: https://github.com/n8fr8/IOCipherCameraExample
 *
 * IOCipher Camera Sample is distributed under this license (aka the 3-clause BSD license)
 *
 * Some of this class was originally part of JCodec ( www.jcodec.org ) This software is distributed
 * under FreeBSD License
 * 
 * @author n8fr8, The JCodec project
 * 
 */
public class ImageToH264MP4Encoder {
    private SeekableByteChannel ch;
    private Picture toEncode;
    private Transform transform;
    private H264Encoder encoder;
    private ArrayList<ByteBuffer> spsList;
    private ArrayList<ByteBuffer> ppsList;
    private FramesMP4MuxerTrack outTrack;
    private ByteBuffer _out;
    private int frameNo;
    private MP4Muxer muxer;

    private PCMMP4MuxerTrack audioTrack;
    private AudioFormat af;
    
    public ImageToH264MP4Encoder(SeekableByteChannel ch, AudioFormat af) throws IOException {
        this.ch = ch;
        this.af = af;
        // Muxer that will store the encoded frames
        muxer = new MP4Muxer(ch, Brand.MP4);

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

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

        // Transform to convert between RGB and YUV
        transform = ColorUtil.getTransform(ColorSpace.RGB, encoder.getSupportedColorSpaces()[0]);

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


        if (af != null)
        	audioTrack = muxer.addPCMAudioTrack(af);
    }

    public void addFrame(Picture pic) throws IOException {
        if (toEncode == null) {
            toEncode = Picture.create(pic.getWidth(), pic.getHeight(), encoder.getSupportedColorSpaces()[0]);
        }

        if (_out == null)
        {
            // Allocate a buffer big enough to hold output frames
            _out = ByteBuffer.allocate(pic.getWidth() * pic.getHeight() * 6);

        }
        
        // Perform conversion
        transform.transform(pic, toEncode);

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

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

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

        frameNo++;
    }
    
    public void addAudio (ByteBuffer buffer) throws IOException
    {
    	audioTrack.addSamples(buffer);
    	
    }

    public void finish() throws IOException {
        // Push saved SPS/PPS to a special storage in MP4
        outTrack.addSampleEntry(H264Utils.createMOVSampleEntry(spsList, ppsList, 4));

        audioTrack.addSampleEntry(MP4Muxer.audioSampleEntry(af));

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