Android从图像列表中制作动画视频

Question

我想通过在两个图像之间应用过渡动画从图像列表中制作动画视频。我在上面发现了很多类似的问题，

Android Screen capturing or make video from images

Android- How to make video using set of images from sd card?

所有类似的问题都建议使用动画，但是我们如何将动画图像存储到视频文件中？有没有Android库支持这个工具来制作图像的视频？

Answer 1

Android不支持AWT的BufferedBitmap，也不支持AWTUtil，这是针对Java的。目前，SequenceEncoder的解决方案已经集成到jcodec的Android版本中。您可以在org.jcodec.api.SequenceEncoder包中使用它。

以下是使用jcodec从一系列位图生成MP4文件的解决方案：

try {
    File file = this.GetSDPathToFile("", "output.mp4");
    SequenceEncoder encoder = new SequenceEncoder(file);

    // only 5 frames in total
    for (int i = 1; i <= 5; i++) {
        // getting bitmap from drawable path
        int bitmapResId = this.getResources().getIdentifier("image" + i, "drawable", this.getPackageName());
        Bitmap bitmap = this.getBitmapFromResources(this.getResources(), bitmapResId);
        encoder.encodeNativeFrame(this.fromBitmap(bitmap));
    }
    encoder.finish();
} catch (IOException e) {
    e.printStackTrace();
}

// get full SD path
File GetSDPathToFile(String filePatho, String fileName) {
    File extBaseDir = Environment.getExternalStorageDirectory();
    if (filePatho == null || filePatho.length() == 0 || filePatho.charAt(0) != '/')
        filePatho = "/" + filePatho;
    makeDirectory(filePatho);
    File file = new File(extBaseDir.getAbsoluteFile() + filePatho);
    return new File(file.getAbsolutePath() + "/" + fileName);// file;
}

// convert from Bitmap to Picture (jcodec native structure)
public Picture fromBitmap(Bitmap src) {
    Picture dst = Picture.create((int)src.getWidth(), (int)src.getHeight(), ColorSpace.RGB);
    fromBitmap(src, dst);
    return dst;
}

public void fromBitmap(Bitmap src, Picture dst) {
    int[] dstData = dst.getPlaneData(0);
    int[] packed = new int[src.getWidth() * src.getHeight()];

    src.getPixels(packed, 0, src.getWidth(), 0, 0, src.getWidth(), src.getHeight());

    for (int i = 0, srcOff = 0, dstOff = 0; i < src.getHeight(); i++) {
        for (int j = 0; j < src.getWidth(); j++, srcOff++, dstOff += 3) {
            int rgb = packed[srcOff];
            dstData[dstOff]     = (rgb >> 16) & 0xff;
            dstData[dstOff + 1] = (rgb >> 8) & 0xff;
            dstData[dstOff + 2] = rgb & 0xff;
        }
    }
}

如果您需要更改fps，您可以自定义SequenceEncoder。

Answer 2

您可以使用名为JCodec ( http://jcodec.org )的纯java解决方案。下面是一个经过修正的简单类，它使用JCodec低级应用程序接口来实现：

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

    public SequenceEncoder(File out) throws IOException {
        this.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 {
        SequenceEncoder encoder = new SequenceEncoder(new File("video.mp4"));
        for (int i = 1; i < 100; i++) {
            BufferedImage bi = ImageIO.read(new File(String.format("folder/img%08d.png", i)));
            encoder.encodeImage(bi);
        }
        encoder.finish();
    }
}