FFmpeg CLI
Process video and audio using FFmpeg CLI for transcoding, cutting, merging, audio extraction, thumbnails, GIFs, speed, filters, subtitles, and watermarks.
ascendswang
@ascendswang
What This Skill Does
Process video and audio files using FFmpeg CLI for tasks like transcoding, cutting, merging, audio extraction, thumbnail generation, GIF creation, speed adjustment, and watermarking. Provides a set of shell scripts that wrap common FFmpeg operations with simple flags.
Replaces manually constructing complex FFmpeg commands by offering ready-to-use scripts for common video and audio processing tasks.
When to Use It
- Cut a segment from a long video file
- Merge multiple video clips into one file
- Extract audio track from a video as MP3
- Generate a thumbnail image from a video at a specific timestamp
- Create an animated GIF from a short video clip
- Add a watermark image overlay to a video
Install
$ openclaw skills install @ascendswang/ffmpeg-cliFFmpeg CLI
Quick Reference
| Task | Command |
|---|---|
| Cut video | {baseDir}/scripts/cut.sh -i <input> -s <start> -e <end> -o <output> |
| Merge clips | {baseDir}/scripts/merge.sh -o <output> <file1> <file2> ... |
| Extract audio | {baseDir}/scripts/extract-audio.sh -i <video> -o <output.mp3> |
| Generate thumbnail | {baseDir}/scripts/thumb.sh -i <video> -t <timestamp> -o <out.jpg> |
| Create GIF | {baseDir}/scripts/gif.sh -i <video> -s <start> -e <end> -o <out.gif> |
| Convert format | {baseDir}/scripts/convert.sh -i <input> -o <output.mp4> |
| Change speed | {baseDir}/scripts/speed.sh -i <input> -r <0.5-2.0> -o <output> |
| Add watermark | {baseDir}/scripts/watermark.sh -i <video> -w <image> -o <output> |
Scripts
cut.sh - Cut video segment
{baseDir}/scripts/cut.sh -i video.mp4 -s 00:01:30 -e 00:02:45 -o clip.mp4
merge.sh - Concatenate videos
{baseDir}/scripts/merge.sh -o merged.mp4 part1.mp4 part2.mp4 part3.mp4
extract-audio.sh - Pull audio track
{baseDir}/scripts/extract-audio.sh -i video.mp4 -o audio.mp3
thumb.sh - Extract frame as image
{baseDir}/scripts/thumb.sh -i video.mp4 -t 00:00:15 -o frame.jpg
gif.sh - Convert clip to GIF
{baseDir}/scripts/gif.sh -i video.mp4 -s 00:00:10 -e 00:00:15 -o clip.gif
convert.sh - Transcode to new format
{baseDir}/scripts/convert.sh -i input.avi -o output.mp4
speed.sh - Adjust playback speed
{baseDir}/scripts/speed.sh -i video.mp4 -r 2.0 -o fast.mp4 # 2x speed
{baseDir}/scripts/speed.sh -i video.mp4 -r 0.5 -o slow.mp4 # 0.5x speed
watermark.sh - Overlay image watermark
{baseDir}/scripts/watermark.sh -i video.mp4 -w logo.png -o output.mp4
Notes
- All scripts support common video formats (mp4, avi, mov, mkv, webm, etc.)
- Output quality is optimized for balanced file size and clarity
- Use
-hor no args to see script usage
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