useful commands for ffmpeg: trim clips, combine videos, etc.
notable flags
| Flag | What | Explain like I'm Five | Example |
|---|---|---|---|
-ss |
start time | where in the input video the clip starts | -ss 03:13:42 |
-t |
time duration | how long the clip should be | -t 00:10:45 |
example
ffmpeg -ss 03:13:42 -i 'input.mp4' -t 00:10:45 -c copy output.mp4notable flags
| Flag | What | Explain like I'm Five | Example |
|---|---|---|---|
-i |
input filelist | a file list txt file containing the paths of the clips to merge | -i filelist.txt |
how filelist.txt looks like
file 'C:\test\clip1.mp4'
file 'C:\test\clip2.mp4'why no re-encoding?
Re-encoding is intentionally omitted to save time and system resources.
when to re-encode?
FFmpeg allows merging videos with small differences in stream properties, such as framerate (FPS). Overriding minor mismatches (e.g., up to 0.5 FPS difference) enables fast concatenation without re-encoding, which is useful for videos recorded on similar devices or settings. However, merging files with larger differences can cause audio/video sync issues or playback glitches. Read more on https://github.com/raymelon/ffmpeg-video-quick-merger-gui
Disclaimer: Only override stream mismatches if the FPS difference is 1-3 FPS (e.g., 27.5 vs 30.0). Merging videos with greater differences may result in audio/video de-synchronization or playback problems. Always watch the merged output to ensure there are no sync issues. Read more on https://github.com/raymelon/ffmpeg-video-quick-merger-gui
example
ffmpeg -f concat -safe -0 -i filelist.txt -c copy output.mp4