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• h264 : make sure the current picture is not made a long ref multiple times

  8 mai 2015, par Anton Khirnov

  h264 : make sure the current picture is not made a long ref multiple times
  Fixes possible invalid reads, once one of those refs is freed, but the
  
  others remain.
  
  CC : libav-stable@libav.org
  

  • [DBH] libavcodec/h264_refs.c

• ffmpeg split videos from times in csv file

  10 juin 2018, par martins

  I’m using Python 3.6. I am trying to split videos into subclips of specified time. I have a folder with 250 ".mp4" files and a separate csv with the times at which I want each video to be subclipped. For instance, a first .mp4 file would be "firstvideo.mp4" up to "twohundredfiftyvideo.mp4". Separately, I have a csv file with each video file name in column A and the timing at which each video needs to be split (column B to I). All videos need to be split into 4 subclips. The .csv looks like :

          col A          col B      col C       colD      colE    .. colI
  
  row1 firstvideo.mp4  00:00:10 - 00:00:20 - 00:01:15 - 00:02:04 .. 00:07:15
  
  row2 secondvideo.mp4 00:00:15 - 00:00:34 - 00:01:05 - 00:01:55 .. 00:08:23

  "firstvideo.mp4" needs a first split from second 10 to 20, a second split from 1m15s - 2m04s and so on (colI is the time at which the fourth subclip should stop). The process should iterate for each of the 250 rows of the csv file corresponding to the 250 mp4 files in a folder.

  So far, the only thing I know is to use ffmpeg to split videos into 4 subclips and generate 4 different output files but do not know how to read from the csv line by line... This is the code I have so far.

  ffmpeg -i firstvideo.mp4 -vcodec copy -acodec copy -ss 00:00:10 -t 00:00:20
  
  firstvideo_1.mp4 -vcodec copy -acodec copy -ss 00:01:15 -t 00:02:04 firstvideo_2.mp4 -vcodec copy -acodec copy -ss 00:03:48 -t 00:04:23 
  
  firstvideo_3.mp4 -vcodec copy -acodec copy -ss 00:05:30 -t 00:07:15 firstvideo_4.mp4

  I name each output file with a _1,_2,_3 or _4 appended to the original video file name. Ideally, I would generate 4 subclips per video (i.e. 250 videos x 4subclip/video = 1,000 mp4 files) and then concatenate each video 4 subclips into one file (i.e. 250 additional files). In fact, I don’t care about the 4 subclips, I’d delete them after they generated my concatenated file.

  Thanks for your time anyways,

• Looping video for x times with ffmpeg [duplicate]

  18 mars 2017, par senty

  This question already has an answer here :

  • PHP Parse/Syntax Errors ; and How to solve them ?
    
    11 answers
    

  I am trying to loop a video input for x times with ffmpeg. I tried the solution that I found on this answer, but it is throwing a syntax error for me

  ffmpeg -f concat -i <(for i in {1..4}; do printf "file '%s'\n" input.mp4; done) -c copy output.mp4

  PHP Parse error : syntax error, unexpected ’’\n" input.mp4 ; done) -c copy ’ (T_CONSTANT_ENCAPSED_STRING), expecting ’,’ or ’)’ in /home/vagrant/Code/index.php

  ---

  I also tried this approach, but this time I am getting another error

  ffmpeg -i input.mp4 -c copy input.mkv
  
  ffmpeg -stream_loop 4 -i input.mkv -c copy looped.mp4

  Unrecognized option ’stream_loop’.

  Error splitting the argument list : Option not found

  ---

  Am I missing out something or is it related with the versions ? I use ffmpeg v2.8.11. I also use php and shell_exec('') for each line.