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• Revision 69babd39f1 : Merge "Fix encoder mem allocation when picture size is changed"

  3 août 2012, par Attila Nagy

  Merge "Fix encoder mem allocation when picture size is changed"

• Revision 965c02c64d : Removing unused YV12_BUFFER_CONFIG arguments from motion search functions. Also

  8 mai 2013, par Dmitry Kovalev

  Changed Paths :
   Modify /vp9/encoder/vp9_mbgraph.c

  
  
  Removing unused YV12_BUFFER_CONFIG arguments from motion search functions.

  Also doing a little bit of cleanup inside vp9_mbgraph.c.

  Change-Id : I9c6711b73810969d2d8fdb19f8edf9ed6e49d1e3

• I need a compact c/c++ code for motion vectors extraction from mp4 file without frame decoding [on hold]

  23 mars 2018, par Andyrey

  I have searched a lot of answers on this kind of question. Many of them point out to code, presuming frame decoding :

  DCT coefficient and motion vector extraction in encoded domain ;
  https://github.com/vadimkantorov/mpegflow ;
  https://github.com/FFmpeg/FFmpeg/blob/master/doc/examples/extract_mvs.c.

  I implemented these codes in my program and saw they decode video frames, and then use frame side data for extracting motion vectors.

  Others give command lines for executing bynaries :

  Motion Vector extraction from encoded video file

  or just gives reference to huge set of library files with no idea what to do with them.

  What I badly need : code for extracting motion vectors from mp4 with no frame decoding (no pixel domain restoring). Is it possible ?

  From my 3rd reference I used code like next, where I suspect frame decoding happens :

  while (ret >= 0)
  
  {
  
      ret = avcodec_receive_frame(video_dec_ctx, frame);
  
     /*I omit some exclusion processing*/
  
      if (ret >= 0)
  
      {
  
          int i;
  
          AVFrameSideData *sd;
  
          video_frame_count++;
  
          sd = av_frame_get_side_data(frame, AV_FRAME_DATA_MOTION_VECTORS);
  
          if (sd)
  
          {
  
              const AVMotionVector *mvs = (const AVMotionVector *)sd->data;
  
              for (i = 0; i < sd->size / sizeof(*mvs); i++)
  
              {
  
                  const AVMotionVector *mv = &mvs[i];
  
                  printf("%d,%2d,%2d,%2d,%4d,%4d,%4d,%4d,0x%"PRIx64"\n",
  
                  video_frame_count, mv->source,
  
                  mv->w, mv->h, mv->src_x, mv->src_y,
  
                  mv->dst_x, mv->dst_y, mv->flags);
  
              }
  
          } 
  
          av_frame_unref(frame);
  
      }
  
  }