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• ffmpeg split video H264 stutters on Windows Media Player

  9 mars 2019, par Juan Foegen

  I am converting and splitting wmv and mp4 into new mp4 files. I am using ffmpeg to do the conversion with simply :
  ffmpeg -i inputfile.wmv -vcodec libx264 -ss 00:00:10 -t 00:00:15 outputfile.mp4

  So when I create my split video it plays fine on other video players, like VLC, but stutters when initially playing on Windows Media Player and even shows a blank screen for a moment and then after about 5 seconds, the video will play normally. If I then select play again without reloading, Windows Media Player will play the video fine, with no stuttering.

  If I REMOVE the start parameter when doing the conversion, then the resulting video will play without issues on all my players, INCLUDING Windows Media Player.

  I have tried changing the frame rate, the bit rate and altered different optimization options mentioned here - https://trac.ffmpeg.org/wiki/Encode/H.264

  I need the split video to play on Windows machines on Windows Media Player and on the web streamed using the video element. This is why I chose H264 codec and MP4.

  Has anyone had issues playing ffmpeg split videos using H264 codec with Windows Media Player ? I am using the latest version of ffmpeg. Anyone have any other suggestions on any different settings I could try to adjust ?

  Thanks

• Revision 6522 : $GLOBALS[’liste_des_forums’] a disparu

  12 juin 2012, par kent1 — Log

  $GLOBALSliste_des_forums ? a disparu

• Retrieving RTP/RTSP Absolute Timestamps through FFmpeg using Opencv

  6 septembre 2019, par Fr0sty

  This is an update to my previous post. I am able to get the RTP timestamps by using ffmpeg and opencv currently, however, I am trying to actually get the timestamp at which the frame was captured. I did a work around to try find the time at which the frame was captured (code is in python).

  seconds_before_frame = cap.getRTPTimeStampSeconds()
  
  fractionofseconds_before_frame = cap.getRTPTimeStampFraction()
  
  ret, frame = cap.read()
  
  seconds_after_frame = cap.getRTPTimeStampSeconds()
  
  fractionofseconds_after_frame = cap.getRTPTimeStampFraction()

  By doing this I found that the time captured was off by 0.02359296 seconds and sometimes 0.2359296 seconds, that’s a lot more than I had expected.

  I found some work arounds with trying to get the timestamp of the frame by using AVFormatContext which I didn’t really understand through the priv_data.

  AVPacket* packet;
  
  av_read_frame(formatCtx, packet);
  
  RTSPState* rtspState = formatCtx->priv_data; 
  
  RTPDemuxContext *rtpdemux = rtspState->rtsp_streams[packet->stream_index]->transport_priv;

  as well as

  RTSPState *state = _formatCtx->priv_data; 
  
  RTSPStream *stream = state->rtsp_streams[0]; 
  
  RTPDemuxContext *demux = stream->transport_priv; 
  
  demux→timestamp

  I’d like to ask how can we call AVFormatContext from C++ side, is it through av_read_frame ? Is it possible to use python bindings or VideoCapture already wraps ffmpeg so there is no need to use av_read_frame but just call VideoCapture ?