Recherche avancée

Sur d’autres sites (17876)

• Can't get video output on avi to mp4 conversion using ffmpeg

  15 avril 2019, par davecgs

  I am so frustrated with this problem. Any time I convert avi files to mp4 files, I can get the audio, but NO video. Here are the various switches I’ve tried. I don’t know how to resolve the situation. I’ve never had this problem with mpg, mov or any other format, but AVI is frustrating.

  Doing this in php but I’ve also done it from the command line.

  (NOTE : I’ve also tried it with NO extra parameters letting ffmpeg do the full conversion).

  (NOTE : It does play the original avi file in any desired Windows or Linux player as is so I know there are is no damage to the original file, but I want to convert to mp4 for the web).

  (Final Note* : when using aac it warns of too many bits ...clamping to max if that helps)

  Here’s the code :

  $InputFile - some avi file. I have a ton of them and they all do the same thing.
  
  
  
  $OutputFile - same name but with an mp4 extension
  
  
  
  $Parameters are various switches I've used. 
  
  
  
  shell_exec ("ffmpeg -i  " . $InputFile . ' ' . $Parameters . ' ' . $OutputFile);
  
  
  
  $Parameters =  " -profile:v baseline -pix_fmt yuv420p ";
  
  
  
  $Parameters = " -acodec copy -vcodec copy ";
  
  
  
  $Parameters = " -c:v libx264 -c:a libfaac -movflags +faststart ";
  
  
  
  $Parameters = " -c:v libx264 -c:a aac -strict experimental -movflags +faststart ";
  
  
  
  $Parameters = " -c:v libx264 -c:a -acodec aac libfdk_aac -movflags +faststart ";
  
  
  
  $Parameters = " -c:v libx264 -preset slow -crf 18 -c:a libmp3lame -b:a 128k -f mp4 ";
  
  
  
  $Parameters =  " -c:v libx264 -crf 19 -preset slow -c:a aac -strict experimental -b:a 192k -ac 2 ";  

  I really don’t get why I only get an audio output. I can see it in VLC player, but, of course that’s not my goal. I want it to mp4 to see it on a webpage.

  I welcome any help !

• Syncronize RTSP with computer time

  17 décembre 2012, par Dídac Pérez

  I am successfully using libav to receive the video stream from an RTSP network source. The point is that I need to syncronize my computer's time with the video capturing, meaning that I need to know which datetime of my computer corresponds to the first frame (pts = 0). My API calls are the following ones :

  av_register_all()
  
  avcodec_register_all()
  
  avformat_network_init()
  
  avformat_open_input()
  
  avformat_find_stream_info()
  
  av_read_play()
  
  loop
  
    av_init_packet()
  
    av_read_frame()
  
    [...]
  
    av_free_packet
  
  end loop

  With the calls above, I successfully read frames, but I do need to know how can I know the exact absolute datetime that corresponds to the first frame, since it has a pts of 0. Maybe I can use a time() function or GetSystemTime (I am using Windows) between two calls of the above, but do not really know how libav works. I will appreciate your help,

  Kind regards,

  Dídac Pérez

• doc/filters/histogram : copyedit for grammar

  10 février 2014, par Werner Robitza

  doc/filters/histogram : copyedit for grammar
  There were a few grammar and spelling mistakes in this filter
  
  description. I went through it and corrected them without changing
  
  the meaning.
  

  • [DH] doc/filters.texi