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I try to figure out how to use FFmpeg to trim videos. I have created a 30 second .mov screen capture using Apple's QuickTime player, and then tried to trim it using three different ways:

  1. Using -copyts, without re-encoding

    ffmpeg -copyts -ss 00:00:10 -i input.mov -to 00:00:15 -map 0 -c copy output.mov
    
  2. Using -copyts, with re-encoding

    ffmpeg -copyts -ss 00:00:10 -i input.mov -to 00:00:15 -c:v libx264 -crf 23 -c:a aac -b:a 192k output.mov
    
  3. Using -trim (with re-encoding, which is the only option):

    ffmpeg -i input.mov -vf trim=10:15 output.mov
    

No matter which approach I tried, the output video is always 15 seconds long and the first 10 seconds of that is just a black screen, whereas what I expected is a 5-second video and without the black screen.

All the three solutions are from here: https://superuser.com/questions/377343/cut-part-from-video-file-from-start-position-to-end-position-with-ffmpeg (answers by @slhck and @malat), and are very high-voted, so I expect they should work without issues, but they don't. Why is that? Is there a problem with the commands, or with the video?

The video is uploaded here: https://github.com/jsx97/test/blob/main/input.mov

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  • from doc: -copyts → Do not process input timestamps, but keep their values without trying to sanitize them. In particular, do not remove the initial start time offset value. If use trim, add setpts -vf trim=10:15,setpts=PTS-STARTPTS Commented Jun 12 at 1:12
  • @БаярГончикжапов That is, if using -copyts, this is a natural behavior? Then this is somewhat strange that "how to trim a video using FFmpeg" solutions , which are often based on -copyts, don't mention this "black screen" issue.
    – jsx97
    Commented Jun 12 at 7:59
  • maybe, it can be used to syncronize videos from surveillance cameras Commented Jun 12 at 8:03
  • @БаярГончикжапов And when you need to trim a video, which approach you use yourself, -trim or something else?
    – jsx97
    Commented Jun 12 at 8:08
  • mostly, ffmpeg -ss 5 -to 15 -i in out Commented Jun 12 at 8:10

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