package org.jcodec.samples.gen;

import static org.jcodec.common.io.NIOUtils.writableChannel;

import java.io.File;
import java.nio.ByteBuffer;

import org.jcodec.codecs.raw.V210Encoder;
import org.jcodec.common.Codec;
import org.jcodec.common.MuxerTrack;
import org.jcodec.common.VideoCodecMeta;
import org.jcodec.common.model.ColorSpace;
import org.jcodec.common.model.Picture8Bit;
import org.jcodec.common.model.Size;
import org.jcodec.common.model.Packet.FrameType;
import org.jcodec.common.tools.MathUtil;
import org.jcodec.containers.mp4.MP4Packet;
import org.jcodec.containers.mp4.muxer.MP4Muxer;

/**
 * This class is part of JCodec ( www.jcodec.org ) This software is distributed
 * under FreeBSD License
 * 
 * This code generates two dark gradients 8bit and 10 bit quantization and saves
 * it into v210 mov
 * 
 * @author The JCodec project
 * 
 */
public class GradGen {
    public static void main(String[] args) throws Exception {
        if (args.length < 2) {
            System.out.println("<out mov> <n frames>");
            return;
        }
        int width = 640;
        int height = 480;
        Picture8Bit pic = Picture8Bit.create(width, height, ColorSpace.YUV422);

        drawGrad(pic.getPlaneData(0), new Size(pic.getWidth(), pic.getHeight()));

        V210Encoder encoder = new V210Encoder();
        MP4Muxer muxer = MP4Muxer.createMP4MuxerToChannel(writableChannel(new File(args[0])));

        ByteBuffer out = ByteBuffer.allocate(width * height * 10);
        ByteBuffer frame = encoder.encodeFrame8Bit(out, pic);

        MuxerTrack videoTrack = muxer.addVideoTrack(Codec.V210, new VideoCodecMeta(new Size(width, height), ColorSpace.YUV422_10));

        for (int i = 0; i < Integer.parseInt(args[1]); i++) {
            videoTrack.addFrame(MP4Packet.createMP4Packet(frame, i * 1001, 24000, 1001, i, FrameType.KEY, null, 0, i * 1001, 0));
        }
        muxer.finish();
    }

    private static void drawGrad(byte[] y, Size ySize) {
        int blockX = ySize.getWidth() / 10;
        int blockY = ySize.getHeight() / 7;

        fillGrad(y, ySize.getWidth(), blockX, blockY, 9 * blockX, 3 * blockY, 0.2, 0.1, 6);
        fillGrad(y, ySize.getWidth(), blockX, 4 * blockY, 9 * blockX, 6 * blockY, 0.2, 0.1, 8);
    }

    private static void fillGrad(byte[] y, int stride, int left, int top, int right, int bottom, double from, double to,
            int quant) {
        int step = stride + left - right;
        int off = top * stride + left;
        for (int j = top; j < bottom; j++) {
            for (int i = left; i < right; i++) {
                y[off++] = colr(((double) i - left) / (right - left), ((double) j - top) / (bottom - top), from, to,
                        quant);
            }
            off += step;
        }
    }

    private static byte colr(double i, double j, double from, double to, int quant) {
        int val = ((int) ((1 << quant) * (from + (to - from) * i))) << (8 - quant);
        return (byte) (MathUtil.clip(val, 0, 255) - 128);
    }
}