FFRtoVFRConverter.java

/*
 * @(#)FFRtoVFRConverter.java  
 * 
 * Copyright (c) 2011 Werner Randelshofer, Goldau, Switzerland.
 * All rights reserved.
 * 
 * You may not use, copy or modify this file, except in compliance with the
 * license agreement you entered into with Werner Randelshofer.
 * For details see accompanying license terms.
 */
package org.monte.media.converter;

import org.monte.media.AbstractVideoCodec;
import org.monte.media.Buffer;
import org.monte.media.Format;
import org.monte.media.math.Rational;
import java.awt.image.BufferedImage;
import java.awt.image.DataBuffer;
import java.awt.image.DataBufferByte;
import java.awt.image.IndexColorModel;
import java.awt.image.Raster;
import java.awt.image.SampleModel;
import java.awt.image.WritableRaster;
import java.util.ArrayList;
import java.util.Arrays;
import static org.monte.media.VideoFormatKeys.*;
import static org.monte.media.BufferFlag.*;

/**
 * This codec converts frames from a fixed frame rate into a variable frame rate
 * by coalescing identical frames.
 * <p>
 * This codec can be used when the input source has a fixed frame rate and
 * the output sink supports a variable frame rate.
 *
 * @author Werner Randelshofer
 * @version $Id: FFRtoVFRConverter.java 299 2013-01-03 07:40:18Z werner $
 */
public class FFRtoVFRConverter extends AbstractVideoCodec {

    private Rational timeStamp;
    private Rational duration;
    private int[] inputColors;
    private int[] previousColors;
    private Object previousPixels;

    public FFRtoVFRConverter() {
        super(new Format[]{
                    new Format(DataClassKey,BufferedImage.class), //
                },
                new Format[]{
                    new Format(DataClassKey,BufferedImage.class,FixedFrameRateKey, false), //
                });
        name = "FFR to VFR";
    }

    @Override
    public Format[] getOutputFormats(Format input) {
        Format forceVFR = new Format(FixedFrameRateKey, false);

        ArrayList<Format> of = new ArrayList<Format>(outputFormats.length);
        for (Format f : outputFormats) {
            of.add(forceVFR.append(f.append(input)));
        }
        return of.toArray(new Format[of.size()]);
    }

    @Override
    public Format setOutputFormat(Format f) {
        Format forceFFR = new Format(FixedFrameRateKey, true);
        Format forceVFR = new Format(FixedFrameRateKey, false);

        for (Format sf : getOutputFormats(f)) {
            if (sf.matches(f)
                    || forceFFR.append(sf).matches(f)
                    || forceVFR.append(sf).matches(f)) {
                this.outputFormat = forceVFR.append(f);
                return sf;
            }
        }
        this.outputFormat = null;
        return null;
    }

    @Override
    public void reset() {
        this.timeStamp = null;
    }

    @Override
    public int process(Buffer in, Buffer out) {
        out.setMetaTo(in);
        Format vf = (Format) inputFormat;

        if (!in.isFlag(KEYFRAME)) {
            // This codec can only process keyframes.
            return CODEC_FAILED;
        }

        if (in.isFlag(END_OF_MEDIA) && in.isFlag(DISCARD)) {
            // => End of media reached. Flush buffer.
            out.setFlag(END_OF_MEDIA, true);
            if (duration.isZero()) {
                out.setFlag(DISCARD, true);
            } else {
                out.setFlag(END_OF_MEDIA, false);
                out.setFlag(DISCARD, false);
                IndexColorModel newColorModel = new IndexColorModel(8, 256, previousColors, 0, false, -1, DataBuffer.TYPE_BYTE);

                WritableRaster newRaster = Raster.createInterleavedRaster(DataBuffer.TYPE_BYTE,
                        vf.get(WidthKey), vf.get(HeightKey), 1, null);
                byte[] newPixels = ((DataBufferByte) newRaster.getDataBuffer()).getData();
                System.arraycopy(previousPixels, 0, newPixels, 0, newPixels.length);

                out.data = new BufferedImage(newColorModel, newRaster, false, null);
                out.sampleDuration = duration;
                out.timeStamp = timeStamp;
                duration = new Rational(0, 1);
            }
            return CODEC_OK;
        }
        if (in.isFlag(DISCARD)) {
            // => Discard discarded buffer.
            out.setFlag(DISCARD, true);
            return CODEC_OK;
        }

        BufferedImage inputImage = (BufferedImage) in.data;
        byte[] inputPixels = ((DataBufferByte) inputImage.getRaster().getDataBuffer()).getData();
        IndexColorModel inputColorModel = (IndexColorModel) inputImage.getColorModel();
        if (inputColors == null) {
            inputColors = new int[256];
        }
        inputColorModel.getRGBs(inputColors);

        if (previousPixels == null) {
            // => First image. Copy data and discard output buffer.
            previousPixels = inputPixels.clone();
            previousColors = inputColors.clone();
            duration = in.sampleDuration;
            timeStamp = in.timeStamp;
            out.setFlag(DISCARD, true);
        } else {
            // => Not the first image. Convert fixed rate to variable rate if images are the same.
            if (Arrays.equals((byte[]) previousPixels, inputPixels)
                    && Arrays.equals(previousColors, inputColors)) {
                duration = duration.add(in.sampleDuration);
                out.setFlag(DISCARD, true);
            } else {
                IndexColorModel newColorModel = new IndexColorModel(8, 256, previousColors, 0, false, -1, DataBuffer.TYPE_BYTE);

                WritableRaster newRaster = Raster.createInterleavedRaster(DataBuffer.TYPE_BYTE,
                        vf.get(WidthKey), vf.get(HeightKey), 1, null);
                byte[] newPixels = ((DataBufferByte) newRaster.getDataBuffer()).getData();
                System.arraycopy(previousPixels, 0, newPixels, 0, newPixels.length);

                out.data = new BufferedImage(newColorModel, newRaster, false, null);
                out.sampleDuration = duration;
                out.timeStamp = timeStamp;
                duration = in.sampleDuration;
                timeStamp = in.timeStamp;
                System.arraycopy(inputPixels, 0, previousPixels, 0, inputPixels.length);
                System.arraycopy(inputColors, 0, previousColors, 0, inputColors.length);

            }

        }
        return CODEC_OK;
    }
}