我一周以来一直在使用xuggle,编写了一个方法用于从视频中获取帧,但如果视频很长,该方法会花费太多时间:
public static void getFrameBySec(IContainer container, int videoStreamId, IStreamCoder videoCoder, IVideoResampler resampler, double sec)
{
BufferedImage javaImage = new BufferedImage(videoCoder.getWidth(), videoCoder.getHeight(), BufferedImage.TYPE_3BYTE_BGR);
IConverter converter = ConverterFactory.createConverter(javaImage, IPixelFormat.Type.BGR24);
IPacket packet = IPacket.make();
while(container.readNextPacket(packet) >= 0)
{
if (packet.getStreamIndex() == videoStreamId)
{
IVideoPicture picture = IVideoPicture.make(videoCoder.getPixelType(), videoCoder.getWidth(), videoCoder.getHeight());
int offset = 0;
while(offset < packet.getSize())
{
int bytesDecoded = videoCoder.decodeVideo(picture, packet, offset);
if (bytesDecoded < 0)
throw new RuntimeException("got error decoding video");
offset += bytesDecoded;
if (picture.isComplete())
{
IVideoPicture newPic = picture;
if (resampler != null)
{
newPic = IVideoPicture.make(resampler.getOutputPixelFormat(), picture.getWidth(), picture.getHeight());
if (resampler.resample(newPic, picture) < 0)
throw new RuntimeException("could not resample video from");
}
if (newPic.getPixelType() != IPixelFormat.Type.BGR24)
throw new RuntimeException("could not decode video as RGB 32 bit data in");
javaImage = converter.toImage(newPic);
try
{
double seconds = ((double)picture.getPts()) / Global.DEFAULT_PTS_PER_SECOND;
if (seconds >= sec && seconds <= (sec +(Global.DEFAULT_PTS_PER_SECOND )))
{
File file = new File(Config.MULTIMEDIA_PATH, "frame_" + sec + ".png");
ImageIO.write(javaImage, "png", file);
System.out.printf("at elapsed time of %6.3f seconds wrote: %s \n", seconds, file);
return;
}
}
catch (Exception e)
{
e.printStackTrace();
}
}
}
}
else
{
// This packet isn't part of our video stream, so we just
// silently drop it.
}
}
converter.delete();
}
你知道一种更好的方法来做这件事吗?