plugins/video-editing/skills/ffmpeg-core/SKILL.md
Provides FFmpeg patterns — trim, concat, convert, extract, codec selection, filter chains. Use when planning or executing video or audio processing tasks.
npx skillsauth add madappgang/magus ffmpeg-coreInstall this skill globally with one command. Works with Claude Code, Cursor, and Windsurf.
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plugin: video-editing updated: 2026-01-20
Production-ready patterns for video and audio manipulation using FFmpeg.
ffmpeg -versionffmpeg -hwaccelsmacOS:
brew install ffmpeg
Linux (Ubuntu/Debian):
sudo apt update && sudo apt install ffmpeg
Linux (Fedora/RHEL):
sudo dnf install ffmpeg
Windows:
# Using Chocolatey
choco install ffmpeg
# Or download from https://ffmpeg.org/download.html
Extract metadata and stream information:
# Get full metadata
ffprobe -v quiet -print_format json -show_format -show_streams "input.mp4"
# Get duration only
ffprobe -v error -show_entries format=duration -of default=noprint_wrappers=1:nokey=1 "input.mp4"
# Get resolution
ffprobe -v error -select_streams v:0 -show_entries stream=width,height -of csv=s=x:p=0 "input.mp4"
# Trim by time (fast, no re-encoding)
ffmpeg -ss 00:01:30 -i input.mp4 -to 00:02:45 -c copy output.mp4
# Trim with re-encoding (frame-accurate)
ffmpeg -ss 00:01:30 -i input.mp4 -to 00:02:45 -c:v libx264 -c:a aac output.mp4
# Extract specific segment by frames
ffmpeg -i input.mp4 -vf "select=between(n\,100\,500)" -vsync vfr output.mp4
# Using concat demuxer (same codecs required)
# First create file list:
# file 'clip1.mp4'
# file 'clip2.mp4'
# file 'clip3.mp4'
ffmpeg -f concat -safe 0 -i filelist.txt -c copy output.mp4
# Using concat filter (different codecs, re-encodes)
ffmpeg -i clip1.mp4 -i clip2.mp4 -filter_complex "[0:v][0:a][1:v][1:a]concat=n=2:v=1:a=1" output.mp4
# MP4 to MOV (ProRes for FCP)
ffmpeg -i input.mp4 -c:v prores_ks -profile:v 3 -c:a pcm_s16le output.mov
# Any to H.264 MP4 (web-friendly)
ffmpeg -i input.avi -c:v libx264 -preset medium -crf 23 -c:a aac -b:a 128k output.mp4
# Extract audio only
ffmpeg -i video.mp4 -vn -c:a libmp3lame -q:a 2 audio.mp3
ffmpeg -i video.mp4 -vn -c:a pcm_s16le audio.wav
# Scale to specific resolution
ffmpeg -i input.mp4 -vf "scale=1920:1080" output.mp4
# Scale maintaining aspect ratio
ffmpeg -i input.mp4 -vf "scale=1920:-1" output.mp4
# Scale to fit within bounds
ffmpeg -i input.mp4 -vf "scale='min(1920,iw)':min'(1080,ih)':force_original_aspect_ratio=decrease" output.mp4
# Adjust volume
ffmpeg -i input.mp4 -af "volume=1.5" output.mp4
# Normalize audio (loudnorm)
ffmpeg -i input.mp4 -af loudnorm=I=-16:TP=-1.5:LRA=11 output.mp4
# Mix audio tracks
ffmpeg -i video.mp4 -i audio.mp3 -filter_complex "[0:a][1:a]amerge=inputs=2" -c:v copy output.mp4
# Replace audio
ffmpeg -i video.mp4 -i new_audio.mp3 -c:v copy -map 0:v:0 -map 1:a:0 output.mp4
# Fade in/out
ffmpeg -i input.mp4 -vf "fade=t=in:st=0:d=1,fade=t=out:st=9:d=1" output.mp4
# Speed adjustment (2x faster)
ffmpeg -i input.mp4 -filter_complex "[0:v]setpts=0.5*PTS[v];[0:a]atempo=2.0[a]" -map "[v]" -map "[a]" output.mp4
# Add text overlay
ffmpeg -i input.mp4 -vf "drawtext=text='Title':fontsize=48:fontcolor=white:x=(w-text_w)/2:y=50" output.mp4
# Color correction
ffmpeg -i input.mp4 -vf "eq=brightness=0.1:saturation=1.2:contrast=1.1" output.mp4
| Use Case | Video Codec | Audio Codec | Container | |----------|-------------|-------------|-----------| | Web delivery | libx264/libx265 | aac | mp4 | | Final Cut Pro | prores_ks | pcm_s16le | mov | | Archive/lossless | ffv1 | flac | mkv | | Quick preview | libx264 -preset ultrafast | aac | mp4 | | Social media | libx264 -crf 20 | aac -b:a 192k | mp4 |
| Profile | Flag | Quality | Use Case | |---------|------|---------|----------| | Proxy | -profile:v 0 | Low | Offline editing | | LT | -profile:v 1 | Medium | Light grading | | Standard | -profile:v 2 | High | General editing | | HQ | -profile:v 3 | Very High | Final delivery | | 4444 | -profile:v 4 | Highest | VFX/compositing |
# Use hardware acceleration (macOS)
ffmpeg -hwaccel videotoolbox -i input.mp4 -c:v h264_videotoolbox output.mp4
# Use hardware acceleration (Linux with NVIDIA)
ffmpeg -hwaccel cuda -i input.mp4 -c:v h264_nvenc output.mp4
# Parallel processing
ffmpeg -i input.mp4 -threads 0 output.mp4
# Limit memory usage
ffmpeg -i input.mp4 -max_muxing_queue_size 1024 output.mp4
# Check if file is valid video
ffprobe -v error -select_streams v:0 -show_entries stream=codec_type -of csv=p=0 "file.mp4" 2>/dev/null
# Returns "video" if valid
# Validate output after processing
validate_video() {
local file="$1"
if ffprobe -v error -select_streams v:0 -show_entries stream=codec_type -of csv=p=0 "$file" 2>/dev/null | grep -q "video"; then
echo "Valid"
return 0
else
echo "Invalid or missing video stream"
return 1
fi
}
testing
A test skill for validation testing. Use when testing skill parsing and validation logic.
tools
--- name: bad-skill description: This skill has invalid YAML in frontmatter allowed-tools: [invalid, array, syntax prerequisites: not-an-array --- # Bad Skill This skill has malformed frontmatter that should fail parsing. The YAML has: - Unclosed array bracket - Wrong type for prerequisites (should be array, not string)
development
Sync model aliases from the curated Firebase database. Fetches default model assignments, short aliases, team compositions, and known model metadata from the claudish API. Run this to get fresh model recommendations.
tools
Release one or more Magus plugins to the distribution repos (magus, magus-alpha, magus-marketing). Handles version inference from git history, marketplace.json updates, tagging, and force-push to lean dist repos. Use whenever the user says "release kanban", "release the dev plugin", "cut a new version of gtd", "bump kanban to 1.7", or hands you a batch like "release kanban and gtd". Also use for multi-plugin releases and for checking what a release would contain before committing.