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• Revision 3331 : On ajoute un accès à la configuration dans les menus

  25 avril 2010, par kent1 — Log

  On ajoute un accès à la configuration dans les menus

• is there a single command to process different audio layouts ? [closed]

  10 août 2023, par Omer Weiss

  I want to use a single ffmpeg command that will output a single stereo audio track.
My problem is that I want to use a single command for 2 possible layouts on the input :
1 : a single stereo track
2 : two mono tracks.

  


  to put in filtergraph terms, the output should have option #1's [0:a:0:0] or option #2's [0:a:0] as Left and option #1's [0:a:0:1] or option #2's [0:a:1] as Right.

  


  Explicit reference results in runtime error (Invalid stream specifier).

  


  this command does the right thing on the single stereo input (op#1) but results in silent Right on 2 mono tracks op#2) :

  


  ffmpeg -i $1 -filter_complex "[0:a]pan=stereo|c0=c0|c1=c1[out]" -map 0:v -map "[out]" -c:v copy -c:a aac -strict experimental -b:a 192k -ac 2 -ar 44100 -acodec aac -ab 192k "merged_$1.mp4"

  


  this command does the right thing on the single stereo input (op#1) but results in silent Right on 2 mono tracks op#2) :

  


  ffmpeg -i $1 -filter_complex "[0:a]pan=stereo|c0=c0|c1=c1[out]" -map 0:v -map "[out]" -c:v copy -c:a aac -strict experimental -b:a 192k -ac 2 -ar 44100 -acodec aac -ab 192k "merged_$1.mp4"

  


  I am looking for ways to suppress 'invalid stream specifier'.

  


• Encoded images into H264 video are skipped and/or missing ?

  25 juillet 2013, par Jona

  I'm trying to encode images into an H264 MP4 video. The issues I'm having is that some of the images are skipped or at the end of the video simply missing. I need the video to play every single image I encode since it is an animation.

  Any help setting the encoder properly would be greatly appreciated !

  Encoder settings :

  AVCodecContext *c;
  
  ...
  
  c->codec_id = AV_CODEC_ID_H264;
  
  c->bit_rate = mOutputWidth*mOutputHeight*4;//400000;
  
  /* Resolution must be a multiple of two. */
  
  c->width    = mOutputWidth;
  
  c->height   = mOutputHeight;
  
      /* timebase: This is the fundamental unit of time (in seconds) in terms
  
       * of which frame timestamps are represented. For fixed-fps content,
  
       * timebase should be 1/framerate and timestamp increments should be
  
       * identical to 1. */
  
  c->time_base.den = mFps;
  
  c->time_base.num = 1;
  
  c->gop_size      = 12; /* emit one intra frame every twelve frames at most */
  
  c->pix_fmt       = AV_PIX_FMT_YUV420P;
  
  ...
  
  av_dict_set(&pOptions, "preset", "medium", 0);
  
  av_dict_set(&pOptions, "tune", "animation", 0);
  
  
  
  /* open the codec */
  
  ret = avcodec_open2(c, codec, &pOptions);
  
  if (ret < 0) {
  
      LOGE("Could not open video codec: %s", av_err2str(ret));
  
      return -1;
  
  }

  Update 07/24/13 :
  I was able to achieve a better video by setting the gop_size=FPS and writing the last video frame repeatedly FPS+1 times seemed to resolve all issues. To me it seems odd to do that but might be something standard in the video encoding world ? Any tips feedback about this ?