Lazycut: A simple terminal video trimmer using FFmpeg

Post by rishabhjajoriya » Mon, Mar 16, 2026, 8:24 PM UTC

Post by c0d3rPrimate » Mon, Mar 16, 2026, 8:54 PM UTC

sorenjan wrote: post #25

ramon156 wrote: post #23

Earlier quoted context omitted.

I don't find Sharing files with people very difficult, just login to your FTP and give an account to another user. - Person commenting on OneDrive

Missed opportunity to reference the famous Dropbox hn comment. I just think there are other closely related use cases where a separate program can add more value, especially in the terminal. I wouldn't suggest most people should use ffmpeg instead of a gui, those are too dissimilar. Another example is cutting out a part of a video, with ffmpeg you need to make two temporary videos and then concatenate them, that proc…

Post by andai » Mon, Mar 16, 2026, 9:48 PM UTC

chris_va wrote: post #34

Invoking ffmpeg, gzip and tar commands is a sort of reverse Turing test for LLMs

Post by neRok » Mon, Mar 16, 2026, 11:23 PM UTC

sorenjan wrote: post #21

I don't find trimming videos with ffmpeg particularly difficult, is just-ss xx -to xx -c copy basically. Sure, you need to get those time stamps using a media player, but you probably already have one so that isn't really an issue. What I've found to be trickier is dividing a video into multiple clips, where one clip can start at the end of another, but not necessarily.

  # make a 6 second long video that alternates from green to red every second.
  ffmpeg -f lavfi -i "color=red[a];color=green[b];[a][b]overlay='mod(floor(t)\,2)*w'" -t 6 master.mp4; # creates 150 frames @ 25fps.

  # try make a 1 second clip starting at 0sec. it should be all green.
  ffmpeg -ss 0 -i "master.mp4" -t 1 -c copy "clip1.mp4"; # exports 27 frames. you see some red.
  ffmpeg -ss 0 -t  1 -i "master.mp4" -c copy "clip2.mp4"; # exports 27 frames. you see some red.
  ffmpeg -ss 0 -to 1 -i "master.mp4" -c copy "clip3.mp4"; # exports 27 frames. you see some red.

  # -t and -to stop after the limit, so subtract a frame. but that leaves 26...
  # so perhaps offset the start time so that frame#0 is at 0.04 (ie, list starts at 1)?
  ffmpeg -itsoffset 0.04 -ss 0 -i "master.mp4" -t 0.96 -c copy "clip4.mp4"; # exports 25 frames, all green, time = 1.00. success.

  # try make another 1 second clip starting at 2sec. it should be all green.
  ffmpeg -itsoffset 0.04 -ss 2 -i "master.mp4" -t 0.96 -c copy "clip5.mp4"; # exports 75 frames, time = 1.08, and you see red-green-red.
  # maybe don't offset the start, and drop 2 at the end?
  ffmpeg -ss 2 -i "master.mp4" -t 0.92 -c copy "clip6.mp4"; # exports 75 frames, time = 1.08, and you see green-red.
  ffmpeg -ss 2 -t 0.92 -i "master.mp4" -c copy "clip7.mp4"; # exports 75 frames, time = 0.92, and you see green-red.
  
  # try something different...
  ffmpeg -ss 2 -i "master.mp4" -c copy -frames 25 "clip8.mp4"; # video is broken.
  ffmpeg -ss 2 -i "master.mp4" -c copy -frames 25 -avoid_negative_ts make_zero "clip9.mp4"; # exports 25 frames, all green, time = 1.00. success?
  # try export a red video the same way.
  ffmpeg -ss 3 -i "master.mp4" -c copy -frames 25 -avoid_negative_ts make_zero "clip10.mp4"; # oh no, it's all green!

Post by skeeter2020 » Mon, Mar 16, 2026, 11:50 PM UTC

sorenjan wrote: post #21

I don't find trimming videos with ffmpeg particularly difficult, is just-ss xx -to xx -c copy basically. Sure, you need to get those time stamps using a media player, but you probably already have one so that isn't really an issue. What I've found to be trickier is dividing a video into multiple clips, where one clip can start at the end of another, but not necessarily.