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• Add custom time to video frames using ffmpeg [migrated]

  16 janvier 2014, par Marco

  I am using ffmpeg to encode raw pixels data (bgr32) into a video file.
  Pixels data is being sent from java application to ffmpeg stdin pipe.

  I am looking for a way to add a timestamp overlay to each frame in the encoded fideo file.
  It looks like there is a way to add a timestamp of current time.
  The instructions could be found here : http://einar.slaskete.net/2011/09/05/adding-time-stamp-overlay-to-video-stream-using-ffmpeg/

  Video files that I am encoding were captured few days ago and I need to add a custom time to each frame. For example 12/12/2013 11:11:45 and not the current time.

  Is it possible to do something like it using ffmpeg ?

  Thank you for your help.

• Theora puts incorrect PTS presentation time on video with held frames

  17 mars 2012, par hexatron

  I have a problem with the packet PTS/DTS on OGG Theora videos with held frames.
  Theora tries to be clever about held frames by omitting duplicate frames
  and using the packet PTS/DTS (they are equal) to skip the held frame time.

  For example, a 2-second-long 10 fps video with frames
  
    A A A A A A A A A A B C D E F G G G G G
  
  should encode with PTS (the frame start) as (note the encoder adds some dup frames)
  
      A 0.0
  
      A 0.1
  
      B 1.0
  
      C 1.1
  
      D 1.2
  
      E 1.3
  
      F 1.4
  
      G 1.5
  
      G 1.9
  
  But libtheora (and ffmpeg) put an incorrect time stamp on frame B
  
  (the first frame following a the dup frames)
  
      B 0.6
  
  This causes video to hiccup on the mislabeled frame.
  
  
  
  My crude fix for this is to use
  
      current frame PTS =  (next frame PTS time) - (one frame time)
  
  and
  
      last frame PTS = duration - (one frame time)

  (I tried submitting a bug report for theora at xiph.org, as the theora site recommends, but could not figure out how to register for a login. I also noticed the reports were several years old, so decided to document this behavior here)

• How to do filter twice at different time ffmpeg

  29 décembre 2022, par Мохамед Русланович

  Am trying to implement overlay twice but at different position and different time
Here is what am trying to do :
i just duplicate the filter

  


  ffmpeg -t 50 -y -i film.mp4 -stream_loop -1 -i gif.gif -filter_complex "


[1]colorchannelmixer=aa=1,scale=iw*2:-1[a];[0][a]overlay=x='200':y='300':shortest=1:enable='between(t,0,10)';

[1]colorchannelmixer=aa=1,scale=iw*2:-1[b];[0][b]overlay=x='200':y='300':shortest=1:enable='between(t,15,20)'"  

-acodec copy output_task_3.mp4


  


  But only the first overlay is been implemented, the seconds is not !

  


  how to archive this ?

  


  Now i wrote a PHP script that dose this filter once each time, and repeat proccess then merge all videos, but this is taking so long.