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• avformat/matroskaenc : Start new cluster if relative timestamp could not otherwise...

  24 juillet 2014, par Michael Niedermayer

  avformat/matroskaenc : Start new cluster if relative timestamp could not otherwise be stored
  Signed-off-by : Michael Niedermayer <michaelni@gmx.at>
  

  • [DH] libavformat/matroskaenc.c

• Revision 674cc787d3 : Update the effective motion vector of sub8x8 blocks This commit enables the vpx

  16 juillet 2014, par Jingning Han

  Changed Paths :
   Modify /vp9/encoder/vp9_encodeframe.c

  
  
  Update the effective motion vector of sub8x8 blocks

  This commit enables the vpxenc to update the effective motion
  vectors stored in the mode_info struct for sub8x8 block coding. It
  resolves the reference motion vector enc/dec mismatch issue.

  Change-Id : I93a88fed6f15fad06a41ca21e297d7281cb75c57

• How can i mux H264 stream into MP4 file via libavformat

  6 janvier 2013, par Brian

  I want to realize an application that firstly decode a multi-media file(such as test.mp4 file, video codec id is H264), get a video stream and an audio stream, then make some different in the audio stream, at last encode the video stream(use libx264) and audio stream into a result file(result.mp4). To promote the efficiency, i omitted the decode and encode of video stream, i get the video packet via function "av_read_frame", then output it directly into the result file via function "av_write_frame". But there is no picture in the output file, and the size of output file is fairly small.

  I tracked the ffmpeg code and found that in the function "av_write_frame->mov_write_packet->ff_mov_write_packet", it will call function "ff_avc_parse_nal_units" to obtain the size of nal unit, but the return value is very small(such as 208 bytes).

  I find that the H264 stream in the MP4 file is not stored in Annex-B format, so it can't find start code(0x000001）， now my problem is how can I change the H264 stream to Annex-B format, and make it work ?
  I added start code at the beginning of every frame manually, but it still not work.

  Anyone can give me any hint ?Thanks very much.
  Following is the codes similar with my :

      // write the stream header, if any
  
      av_write_header(pFormatCtxEnc);
  
  
  
      .........
  
      /**
  
      * Init of Encoder and Decoder
  
      */
  
  
  
      bool KeyFlag = false;
  
      bool KeyFlagEx = false;
  
      // Read frames and save frames to disk
  
      int iPts = 1;
  
      av_init_packet(&packet);
  
      while(av_read_frame(pFormatCtxDec, &packet)>=0)
  
      {
  
              if (packet.flags == 1)
  
                      KeyFlag = true;
  
  
  
              if (!KeyFlag)
  
                      continue;
  
  
  
              if (m_bStop)
  
              {
  
                      break;
  
              }
  
  
  
              // Is this a packet from the video stream?
  
              if(packet.stream_index == videoStream)
  
              {
  
                      currentframeNum ++;
  
                      if (progressCB != NULL && currentframeNum%20 == 0)
  
                      {
  
                              float fpercent = (float)currentframeNum/frameNum;
  
                              progressCB(fpercent,m_pUser);
  
                      }
  
  
  
                      if (currentframeNum >= beginFrame && currentframeNum <= endFrane)
  
                      {
  
                              if (packet.flags == 1)
  
                                      KeyFlagEx = true;
  
  
  
                              if (!KeyFlagEx)
  
                                      continue;
  
                              packet.dts = iPts ++;
  
                              av_write_frame(pFormatCtxEnc, &packet);
  
  
  
                      }
  
              }
  
              // Free the packet that was allocated by av_read_frame
  
      }
  
  
  
      // write the trailer, if any
  
      av_write_trailer(pFormatCtxEnc);
  
  
  
      /**
  
      * Release of encoder and decoder
  
      */
  
  
  
      return true;