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I use this to cut a part out of a mp4 file:

ffmpeg -i input.mp4 -vcodec copy -acodec copy -ss 00:36:18 -to 00:39:50 output.mp4

It works good but the video image is always freezed in the beginning for 1 second.

Doesnt matter which video file I try and cut a part out of, it takes like 1 second before the video start.

Heres an example:

Why?

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1
  • It seems your youtube link is down, could you please keep the example live such that the question remains useful for future visitors?
    – Saaru Lindestøkke
    Oct 18, 2015 at 12:41

3 Answers 3

Reset to default
8

The order of the parameters is very important on ffmpeg.
Try this:

ffmpeg -ss 00:36:18 -i input.mp4 -vcodec copy -acodec copy -to 00:39:50 output.mp4

It seems that setting the -ss parameter before -i sets a keyframe at the beginning of the newly generated video.
Or so I understand from the Wiki page here.

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  • 1
    Minor note: That's the wiki, not the official documentation. The wiki articles are written by users to supplement the docs, so they may contain less accurate information.
    – llogan
    Oct 17, 2015 at 17:55
  • This was the answer which helped me to solve the issue.
    – Amessihel
    Nov 7, 2020 at 17:24
3

The video freezes because you aren't cutting at an I-frame, while using stream-copy mode. You'll have to re-encode the video, or choose a different start point, which happens to be an I-frame.

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3
0

What works for me was:

ffmpeg -ss 00:01:00 -i video.mp4 -to 00:02:00 -c:v libx264 -c:a aac cut.mp4

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