OpenMontage video-edit
install
source · Clone the upstream repo
git clone https://github.com/calesthio/OpenMontage
Claude Code · Install into ~/.claude/skills/
T=$(mktemp -d) && git clone --depth=1 https://github.com/calesthio/OpenMontage "$T" && mkdir -p ~/.claude/skills && cp -r "$T/.claude/skills/video-edit" ~/.claude/skills/calesthio-openmontage-video-edit-25a8a9 && rm -rf "$T"
manifest:
.claude/skills/video-edit/SKILL.mdsource content
Video Edit
Edit videos locally by running ffmpeg/ffprobe directly. No wrapper scripts needed.
Prerequisites
Install ffmpeg (includes ffprobe):
# macOS brew install ffmpeg # Ubuntu/Debian sudo apt update && sudo apt install -y ffmpeg # Verify ffmpeg -version && ffprobe -version
Quick Reference
Get video info
ffprobe -v quiet -print_format json -show_format -show_streams video.mp4
Trim
ffmpeg -y -ss 00:00:30 -to 00:01:45 -i video.mp4 -c copy trimmed.mp4
Concatenate clips
# 1. Create a file list printf "file '%s'\n" clip1.mp4 clip2.mp4 clip3.mp4 > list.txt # 2. Concat with stream copy ffmpeg -y -f concat -safe 0 -i list.txt -c copy joined.mp4
Resize for platform
ffmpeg -y -i video.mp4 \ -vf "scale=1080:1920:force_original_aspect_ratio=decrease,pad=1080:1920:(ow-iw)/2:(oh-ih)/2:black" \ -c:a copy tiktok.mp4
Change speed
# 2x faster ffmpeg -y -i video.mp4 -filter:v "setpts=0.5*PTS" -filter:a "atempo=2.0" fast.mp4 # 0.5x (slow motion) ffmpeg -y -i video.mp4 -filter:v "setpts=2.0*PTS" -filter:a "atempo=0.5" slow.mp4
Extract audio
ffmpeg -y -i video.mp4 -vn -acodec libmp3lame audio.mp3
Replace audio
ffmpeg -y -i video.mp4 -i audio.mp3 -c:v copy -map 0:v:0 -map 1:a:0 -shortest output.mp4
Compress
ffmpeg -y -i video.mp4 -crf 23 -preset medium -c:a copy compressed.mp4
Convert format
ffmpeg -y -i video.mov output.mp4
Add image overlay
# Logo in top-right corner ffmpeg -y -i video.mp4 -i logo.png \ -filter_complex "overlay=W-w-10:10" -c:a copy watermarked.mp4
Platform Presets
| Platform | Resolution | Scale + pad filter |
|---|---|---|
| TikTok | 1080 x 1920 | |
| YouTube | 1920 x 1080 | |
| 1080 x 1350 | | |
| Square | 1080 x 1080 | |
| Twitter/X | 1920 x 1080 | |
Use the filter with:
ffmpeg -y -i input.mp4 -vf "<filter>" -c:a copy output.mp4
Tips
- Always use
to overwrite output without prompting.-y - Use
when you only need to cut/join (no re-encoding, very fast).-c copy - Lower CRF = better quality, larger file. Range 18-28 is typical; 23 is the default.
- For detailed recipes and flag explanations, see
.references/operations.md