android - Android从图像列表制作动画视频

Question

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

Android 屏幕捕获或从图像制作视频

Android-如何使用 sd 卡中的一组图像制作视频？

所有类似的 SO 问题都建议为此使用动画，但是我们如何将动画图像存储到视频文件中？是否有任何 Android 库支持此功能来制作图像视频？

Answer 1

Android 不支持 AWT 的 BufferedBitmap 也不支持 AWTUtil，即用于 Java SE。目前，带有 SequenceEncoder 的解决方案已经集成到 jcodec 的 Android 版本中。您可以从包 org.jcodec.api.SequenceEncoder 中使用它。

这是使用 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。这是一个使用 JCodec 低级 API 的CORRECTED简单类：

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();
    }
}