我正在尝试制作一个可以对h.264视频进行编码和解码的程序,以便可以编辑该视频。
如果我想用Java制作此程序,谁能告诉我该怎么做?
最佳答案
您可以使用JCodec(http://jcodec.org)。
要解码视频序列,请执行以下操作:
int frameNumber = 10000;
FileChannelWrapper ch = null;
try {
ch = NIOUtils.readableFileChannel(new File(path to mp4));
FrameGrab frameGrab = new FrameGrab(ch);
frameGrab.seek(frameNumber);
Picture frame;
for (int i = 0; (frame = frameGrab.getNativeFrame()) != null && i < 200; i++) {
// Do something
}
} finally {
NIOUtils.closeQuietly(ch);
}
编码序列:
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(Picture bi) throws IOException {
if (toEncode == null) {
toEncode = Picture.create(bi.getWidth(), bi.getHeight(), ColorSpace.YUV420);
}
// Perform conversion ( RGB -> YUV )
transform.transform(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);
}
}
最后,使用 Android图像将转换为和,请使用:
public static Picture fromBitmap(Bitmap src) {
Picture dst = Picture.create((int)src.getWidth(), (int)src.getHeight(), RGB);
fromBitmap(src, dst);
return dst;
}
public static 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;
}
}
}
public static Bitmap toBitmap(Picture src) {
Bitmap dst = Bitmap.create(pic.getWidth(), pic.getHeight(), ARGB_8888);
toBitmap(src, dst);
return dst;
}
public static void toBitmap(Picture src, Bitmap dst) {
int[] srcData = src.getPlaneData(0);
int[] packed = new int[src.getWidth() * src.getHeight()];
for (int i = 0, dstOff = 0, srcOff = 0; i < src.getHeight(); i++) {
for (int j = 0; j < src.getWidth(); j++, dstOff++, srcOff += 3) {
packed[dstOff] = (srcData[srcOff] << 16) | (srcData[srcOff + 1] << 8) | srcData[srcOff + 2];
}
}
dst.setPixels(packed, 0, src.getWidth(), 0, 0, src.getWidth(), src.getHeight());
}
最终在解码时会得到,您会得到YUV帧,以便将其转换为RGB帧:
Transform transform = ColorUtil.getTransform(pic.getColor(), ColorSpace.RGB);
Picture rgb = Picture.create(pic.getWidth(), pic.getHeight(), ColorSpace.RGB);
transform.transform(pic, rgb);
并确保您下载的JAR包含所有部门:http://jcodec.org/downloads/jcodec-0.1.3-uberjar.jar