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• cutting multiple segments with ffmpeg [duplicate]

  13 juin 2018, par B Pulsart

  This question already has an answer here :

  • Every 30 seconds is to cut a video 3s
    
    1 answer
    

  So there is a 10 min long .mp4 and I have to cut it in 2 seconds long segments every 10 seconds, then concatenate all 2 sec segments together to get a 2 min long film.

  I manage to do that with a loop in python that subprocep ffmpeg, but it’s long and ugly (cut, cut cut... and then glue)

  Is it a way to do that with just a line in ffmpeg ?

  my code in python for cutting sequences :

  import subprocess# as sp
  
  
  
  ffmpeg = file on disk # on Windows
  
  film_in =  a file name
  
  
  
  t_total = 10#min
  
  t_sec = t_total*60
  
  
  
  def c_cut(time) :
  
      cmd = [ffmpeg  , '-i' ,film_in ,'-b:v', '800k' ,'-ss', str(time) , '-t','2' , '-an', film_out]
  
      return cmd
  
  
  
  
  
  for tps in range(0, t_sec, 10) :
  
      film_out = a file name unique for each segment
  
      command = c_cut(tps)
  
      subprocess.call(command)

• ffmpeg combined video increaes duration

  4 septembre 2022, par Imants Gulbis

  I am splitting video file in scenes and then process them. After processing and combining them I gain a lot of extra seconds. Original duration 24:29 after combining 24:59.

  


  First I split video with this command

  


  ffmpeg -i test.mkv -f segment -c copy -map 0 -y $HOME/Encoding/SPLIT/OUTPUT-%07d.mkv


  


  And then I process each file encoding x264 to AV1 :

  


  ffmpeg -i $HOME/Encoding/SPLIT/OUTPUT-0000125.mkv -map 0:0 -pix_fmt yuv420p10le -strict -1 -f yuv4mpegpipe /tmp/fifo_stream

SvtAv1EncApp -i /tmp/fifo_stream --profile 0 --preset 6 --qp 35 --max-qp 63 --min-qp 1 --rc 0 --keyint 240 --input-depth 10 --crf 30 --rc 0 --passes 2 --film-grain 0 -b $HOME/Encoding/CONVERTED/OUTPUT-0000125.ivf


  


  and store information about every converted file in $HOME/Encoding/list.txt file

  


  Then I combine files :

  


  ffmpeg -f concat -safe 0 -i $HOME/Encoding/list.txt -y $HOME/Encoding/encoded.mp4


  


  result video gained extra 30 seconds. Someone knows what to do so that combined file duration will be same as original ?

  


• avformat/segafilmenc - set keyframe bit correctly

  5 mai 2018, par Gyan Doshi

  avformat/segafilmenc - set keyframe bit correctly
  As per
  
  https://web.archive.org/web/20020803104640/http://www.pcisys.net:80/~melanson/codecs/film-format.txt,
  the top bit of the info1 chunk is set as 1 for inter-coded frames and 0
  
  otherwise.
  

  • [DH] libavformat/segafilmenc.c
  • [DH] libavformat/version.h