Advanced search

On other websites (6457)

• ffmpeg sync parts of video or exclude intersection frames

  25 October 2014, by NadY

  I have two video files that make part of a bigger one, but both parts contain a portion that repeats itself.
  Eg. v1: 00m-16m ; v2: 10m-20m ; the part that repeats in both videos it’s 10m-16m

  Is there a way I could recreate the big video by automatically detect the intersection and exclude it from one of the videos? Or can I find the time interval of the intersection?

  Thanks!

• FFMPEG : Cut specific parts of a video, and merge them in a single file

  19 February 2017, by Jay D.

  I would like to cut out specific parts of a mp4 video, and merge back those parts to create a single video file. This is to make an animated preview of the video.

  More specifically :
  Cut out these parts of a video :

  • Part 1 : start time of the cut = 20% of total time ; end time of the
    cut = 20% of total time + 3seconds,
  • Part 2 : 40% of total time ; 40%nof total time + 3 seconds
  • Part 3 : 60% of total time ; 60% of total time + 3 seconds
  • Part 4 : 80% of total time ; 80% of total time + 3 seconds

  (The videos are more than 3 minutes long, so there should not be any overlap in the parts)

  Then merge those 4 parts in a new mp4 video file. How do you do that with FFMPEG ?

  Edit : so this is as far as I got for this question :

  I found answers to questions on "Superuser" and "Stackexchange" for these questions on FFMPEG:
   How to get video durations in seconds
   Cut part from video file with start/end positions
   Concatenate mp4 files

  So : Get total time of video :

  $ ffprobe -v error -show_entries format=duration \
  
    -of default=noprint_wrappers=1:nokey=1 -sexagesimal inputvideo.mp4

  With the -sexagesimal I should get the right time format to use after.

  Cut out part of video

  ffmpeg -ss [start] -i in.mp4 -t [duration] -c copy /path/videopart[number].mp4

  Right here I don’t know :
  How to do an operation on total time (20%, 40%... then 20% +3 seconds, 40% +3 seconds..)
  How to properly implement it in the code line

  Create a file videoparts.txt with the files names :

  $ cat videoparts.txt
  
  file '/path/videopart1.mp4'
  
  file '/path/videopart2.mp4'
  
  file '/path/videopart3.mp4'
  
  file '/path/videopart4.mp4'

  Then this should merge them in a single file :

  $ ffmpeg -f concat -i videoparts.txt -c copy outputvideo.mp4

• avdevice/oss_dec: account for sample size when computing timestamp

  1 June 2022, by Matt Jacobson

  avdevice/oss_dec: account for sample size when computing timestamp
  Don't assume each sample is one byte in size. Doing so results in wrong and
  
  occasionally non-monotonically-increasing timestamps.
  Fix nearby cosmetic typo.
  Signed-off-by: Marton Balint <cus@passwd.hu>
  

  • [DH] libavdevice/oss.c
  • [DH] libavdevice/oss.h
  • [DH] libavdevice/oss_dec.c