xuggle学习-视频解码
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//新建容器，以供容纳流 IContainer container = IContainer.make(); //开始读流 if (container.open(filename, IContainer.Type.READ, null) < 0) throw new IllegalArgumentException("could not open file: " + filename); //获取流数 int numStreams = container.getNumStreams(); int videoStreamId = -1; IStreamCoder videoCoder = null; //从流中识别视频流 for (int i = 0; i < numStreams; i++) { IStream stream = container.getStream(i); IStreamCoder coder = stream.getStreamCoder(); if (coder.getCodecType() == ICodec.Type.CODEC_TYPE_VIDEO) { videoStreamId = i; videoCoder = coder; break; } } if (videoStreamId == -1) throw new RuntimeException("could not find video stream in container: " + filename); //读取视频流 if (videoCoder.open() < 0) throw new RuntimeException("could not open video decoder for container: " + filename); IVideoResampler resampler = null; //重新编码图片格式 if (videoCoder.getPixelType() != IPixelFormat.Type.BGR24) { resampler = IVideoResampler.make(videoCoder.getWidth(), videoCoder.getHeight(), IPixelFormat.Type.BGR24, videoCoder.getWidth(), videoCoder.getHeight(), videoCoder.getPixelType()); if (resampler == null) throw new RuntimeException("could not create color space " + "resampler for: " + filename); } // 循环读取 IPacket packet = IPacket.make(); long firstTimestampInStream = Global.NO_PTS; long systemClockStartTime = 0; while (container.readNextPacket(packet) >= 0) { if (packet.getStreamIndex() == videoStreamId)//识别视频流 { //图片编码 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 in: " + filename); offset += bytesDecoded; //图片帧已读取完，保存图片 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: " + filename); } if (newPic.getPixelType() != IPixelFormat.Type.BGR24) throw new RuntimeException("could not decode video" + " as BGR 24 bit data in: " + filename); BufferedImage javaImage = Utils.videoPictureToImage(newPic); //保存图片到本地 processFrame(picture, image); } } } } }/** * 根据固定间隔采集图片 */private static void processFrame(IVideoPicture picture, BufferedImage image) { try { //mLastPtsWrite记录最近一次图片采集时间 //NANO_SECONDS_BETWEEN_FRAMES，纳秒时间间隔 if(mLastPtsWrite == Global.NO_PTS) mLastPtsWrite = picture.getPts() - NANO_SECONDS_BETWEEN_FRAMES; //每隔NANO_SECONDS_BETWEEN_FRAMES采集 if(picture.getPts() - mLastPtsWrite >= NANO_SECONDS_BETWEEN_FRAMES) { File file = new File("c:/1/" + i + ".jpg"); i++; ImageIO.write(image, "jpg", file); double seconds = ((double)picture.getPts()) / Global.DEFAULT_PTS_PER_SECOND; System.out.printf("at elapsed time of %6.3f seconds wrote: %s\n", seconds, file); mLastPtsWrite += NANO_SECONDS_BETWEEN_FRAMES; } } catch (Exception e) { e.printStackTrace(); }}
