Question

我正在尝试使用JCodec将一系列图像转换为Java SE桌面应用程序内的视频。我尝试过的几种方法都导致了Windows Media Player无法播放的视频。

我不清楚这是编解码器问题（可疑）还是我没有正确创建视频。当我尝试在Windows Media Player中播放视频时，我得到：

Windows Media Player无法播放该文件。玩家可能没有支持文件类型或可能不支持以前使用的编解码器压缩文件。

这是我最近一直在使用的拼凑在一起的样本。我真的不明白视频格式的内部，所以我甚至不完全确定一些代码在做什么。

import java.awt.image.BufferedImage;
import java.io.File;
import java.io.IOException;
import java.nio.ByteBuffer;
import java.util.ArrayList;
import java.util.Arrays;

import javax.imageio.ImageIO;

import org.jcodec.codecs.h264.H264Encoder;
import org.jcodec.codecs.h264.H264Utils;
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.scale.AWTUtil;
import org.jcodec.scale.RgbToYuv420;

public class CreateVideo {
    private SeekableByteChannel ch;
    private Picture toEncode;
    private RgbToYuv420 transform;
    private H264Encoder encoder;
    private ArrayList<ByteBuffer> spsList;
    private ArrayList<ByteBuffer> ppsList;
    private FramesMP4MuxerTrack outTrack;
    private ByteBuffer _out;
    private int frameNo;
    private MP4Muxer muxer;

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

        // Transform to convert between RGB and YUV
        transform = new RgbToYuv420(0, 0);

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

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

        // Allocate a buffer big enough to hold output frames
        _out = ByteBuffer.allocate(1920 * 1080 * 6);

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

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

    }

    public void encodeImage(BufferedImage bi) throws IOException {
        if (toEncode == null) {
            toEncode = Picture.create(bi.getWidth(), bi.getHeight(), ColorSpace.YUV420);
        }

        // Perform conversion
        for (int i = 0; i < 3; i++) {
            Arrays.fill(toEncode.getData()[i], 0);
        }
        transform.transform(AWTUtil.fromBufferedImage(bi), toEncode);

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

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

        // Add packet to video track
        outTrack.addFrame(new MP4Packet(result, 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(H264Utils.createMOVSampleEntry(spsList, ppsList));

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

    public static void main(String[] args) throws IOException {
        CreateVideo encoder = new CreateVideo(new File("C:\\video\\video.mp4"));
        for (int i = 10; i < 34; i++) {
            String filename = String.format("C:\\video\\%02d.png", i);
            BufferedImage bi = ImageIO.read(new File(filename));
            encoder.encodeImage(bi);
        }
        encoder.finish();
    }
}

如果有一些更简单的编解码器/容器，我就不依赖于H264或MP4。唯一的要求是它应该在没有安装其他软件的基准Windows 7机器上播放。

Answer 1

我在jcodec的RgbToYuv420（）转换中遇到了很多问题。
我使用自己的函数将RGB BufferedImage转换为Yuv420 我遇到的一个问题是RgbToYuv420平均计算的upix和vpix 价值，这导致我的mp4中的颜色都很难受。

// make a YUV420J out of BufferedImage pixels
private Picture makeFrame(BufferedImage bi, ColorSpace cs)
{   
    DataBuffer imgdata = bi.getRaster().getDataBuffer();
    int[] ypix = new int[imgdata.getSize()];
    int[] upix = new int[ imgdata.getSize() >> 2 ];
    int[] vpix = new int[ imgdata.getSize() >> 2 ];
    int ipx = 0, uvoff = 0;

    for (int h = 0; h < bi.getHeight(); h++) {
        for (int w = 0; w < bi.getWidth();  w++) {
            int elem = imgdata.getElem(ipx);
            int r = 0x0ff & (elem >>> 16);
            int g = 0x0ff & (elem >>> 8);
            int b = 0x0ff & elem;
            ypix[ipx] = ((66 * r + 129 * g + 25 * b) >> 8) + 16;
            if ((0 != w % 2) && (0 != h % 2)) {
                upix[uvoff] = (( -38 * r + -74 * g + 112 * b) >> 8) + 128;
                vpix[uvoff] = (( 112 * r + -94 * g + -18 * b) >> 8) + 128;
                uvoff++;
            }
            ipx++;
        }
    }
    int[][] pix = { ypix, upix, vpix, null };
    return new Picture(bi.getWidth(), bi.getHeight(), pix, ColorSpace.YUV420J);
}

Answer 2

现在有0.2.0，https://github.com/jcodec/jcodec/blob/master/javase/src/main/java/org/jcodec/api/awt/AWTSequenceEncoder8Bit.java

此示例创建一个具有固定背景和叠加动画的MP4。没声音。

    AWTSequenceEncoder8Bit enc = AWTSequenceEncoder8Bit.create2997Fps(outputMovieFile); 
    int framesToEncode = (int) (29.97 * durationInSeconds);
    java.awt.image.BufferedImage image = ...(some background image)

    for (int frameIndx = 0, x = 0, y = 0, incX = speed, incY = speed; frameIndx < framesToEncode; frameIndx++, x += incX, y += incY) {
        Graphics g = image.getGraphics();
        g.setColor(Color.YELLOW);
        if (x >= image.getWidth() - ballSize) incX = -speed;
        if (y >= image.getHeight() - ballSize) incY = -speed;
        if (x <= 0) incX = speed;
        if (y <= 0) incY = speed;
        g.fillOval(x, y, ballSize, ballSize);
        enc.encodeImage(image);
    }
    enc.finish();

如何使用JCodec将一系列图像转换为视频？

2 个答案: