Question

有人可以推荐一个允许我以编程方式创建视频的Java库吗？具体来说，它将执行以下操作：

采用一系列BufferedImages作为框架
允许添加背景WAV / MP3
允许'偶然'WAV / MP3以任意方式，以编程方式指定的点添加
以通用格式（MPEG等）输出视频

有人可以推荐什么吗？对于图像/声音混合，我甚至会使用一系列帧，并且对于每个帧，我必须提供与该帧相关联的未压缩声音数据的原始字节。

P.S。如果Java Media Framework有调用来实现上述目标，它甚至不必是一个“第三方库”，但是从我粗略的记忆中我感觉它没有。

Answer 1

我已经使用下面提到的代码在纯Java中的需求列表上成功执行了第1,2和4项。值得一看，你可能想出如何包含＃3。

http://www.randelshofer.ch/blog/2010/10/writing-quicktime-movies-in-pure-java/

Answer 2

我找到了一个名为ffmpeg的工具，它可以将多媒体文件从一种格式转换为另一种格式。在ffmpeg中有一个名为libavfilter的过滤器，它是vhook的替代品，它允许在解码器和编码器之间修改或检查视频/音频。我认为应该可以输入原始帧并生成视频。我研究了ffmpeg的任何java实现，并找到了标题为"Getting Started with FFMPEG-JAVA"的页面，它是使用JNA围绕FFMPEG的JAVA包装器。

Answer 3

您可以尝试一个名为JCodec的纯Java编解码器库它有一个非常基本的H.264（AVC）编码器和MP4复用器。以下是从他们的样本中获取的完整示例代码 - TranscodeMain。

private static void png2avc(String pattern, String out) throws IOException {
    FileChannel sink = null;
    try {
        sink = new FileOutputStream(new File(out)).getChannel();
        H264Encoder encoder = new H264Encoder();
        RgbToYuv420 transform = new RgbToYuv420(0, 0);

        int i;
        for (i = 0; i < 10000; i++) {
            File nextImg = new File(String.format(pattern, i));
            if (!nextImg.exists())
                continue;
            BufferedImage rgb = ImageIO.read(nextImg);
            Picture yuv = Picture.create(rgb.getWidth(), rgb.getHeight(), ColorSpace.YUV420);
            transform.transform(AWTUtil.fromBufferedImage(rgb), yuv);
            ByteBuffer buf = ByteBuffer.allocate(rgb.getWidth() * rgb.getHeight() * 3);

            ByteBuffer ff = encoder.encodeFrame(buf, yuv);
            sink.write(ff);
        }
        if (i == 1) {
            System.out.println("Image sequence not found");
            return;
        }
    } finally {
        if (sink != null)
            sink.close();
    }
}

此示例更复杂，实际上显示了编码帧到MP4文件的多路复用：

private static void prores2avc(String in, String out, ProresDecoder decoder, RateControl rc) throws IOException {
    SeekableByteChannel sink = null;
    SeekableByteChannel source = null;
    try {
        sink = writableFileChannel(out);
        source = readableFileChannel(in);

        MP4Demuxer demux = new MP4Demuxer(source);
        MP4Muxer muxer = new MP4Muxer(sink, Brand.MOV);

        Transform transform = new Yuv422pToYuv420p(0, 2);

        H264Encoder encoder = new H264Encoder(rc);

        MP4DemuxerTrack inTrack = demux.getVideoTrack();
        CompressedTrack outTrack = muxer.addTrackForCompressed(TrackType.VIDEO, (int) inTrack.getTimescale());

        VideoSampleEntry ine = (VideoSampleEntry) inTrack.getSampleEntries()[0];
        Picture target1 = Picture.create(ine.getWidth(), ine.getHeight(), ColorSpace.YUV422_10);
        Picture target2 = null;
        ByteBuffer _out = ByteBuffer.allocate(ine.getWidth() * ine.getHeight() * 6);

        ArrayList<ByteBuffer> spsList = new ArrayList<ByteBuffer>();
        ArrayList<ByteBuffer> ppsList = new ArrayList<ByteBuffer>();
        Packet inFrame;
        int totalFrames = (int) inTrack.getFrameCount();
        long start = System.currentTimeMillis();
        for (int i = 0; (inFrame = inTrack.getFrames(1)) != null && i < 100; i++) {
            Picture dec = decoder.decodeFrame(inFrame.getData(), target1.getData());
            if (target2 == null) {
                target2 = Picture.create(dec.getWidth(), dec.getHeight(), ColorSpace.YUV420);
            }
            transform.transform(dec, target2);
            _out.clear();
            ByteBuffer result = encoder.encodeFrame(_out, target2);
            if (rc instanceof ConstantRateControl) {
                int mbWidth = (dec.getWidth() + 15) >> 4;
                int mbHeight = (dec.getHeight() + 15) >> 4;
                result.limit(((ConstantRateControl) rc).calcFrameSize(mbWidth * mbHeight));
            }
            spsList.clear();
            ppsList.clear();
            H264Utils.encodeMOVPacket(result, spsList, ppsList);
            outTrack.addFrame(new MP4Packet((MP4Packet) inFrame, result));
            if (i % 100 == 0) {
                long elapse = System.currentTimeMillis() - start;
                System.out.println((i * 100 / totalFrames) + "%, " + (i * 1000 / elapse) + "fps");
            }
        }
        outTrack.addSampleEntry(H264Utils.createMOVSampleEntry(spsList, ppsList));

        muxer.writeHeader();
    } finally {
        if (sink != null)
            sink.close();
        if (source != null)
            source.close();
    }
}