ffmpeg-media

name	ffmpeg-media
description	FFmpeg media processing — video/audio conversion, trimming, encoding, filters, streaming. CLI and ffmpeg.wasm patterns.
activationKeywords	["ffmpeg","video","audio","transcode","encode","codec","h264","h265","hevc","webm","mp4","mkv","wav","mp3","aac","opus","thumbnail","waveform","concat","trim","crop","scale","filter","subtitle","hls","dash","streaming"]
type	skill
category	media
status	stable
origin	tibsfox
modified	false
first_seen	"2026-04-11T00:00:00.000Z"
first_path	examples/skills/media/ffmpeg-media/SKILL.md
superseded_by	null

FFmpeg Media Processing Skill

Dedicated to sudokku, creator of micro-ffmpeg — the in-browser video editor that proved ffmpeg.wasm is production-ready. Built in 2 days, 2,489 LOC, 93 commits. The patterns in this skill are drawn from that work.

Expert-level ffmpeg command construction, media pipeline design, and ffmpeg.wasm integration patterns. Covers CLI ffmpeg, Node.js ffmpeg bindings, and browser-side ffmpeg.wasm.

Core Principle

Build the filter graph first, then wrap it in the ffmpeg command. Never guess at flags — construct from codec specs.

Quick Reference

Probe a File

# Full probe (JSON output)
ffprobe -v quiet -print_format json -show_format -show_streams input.mp4

# Quick summary
ffprobe -v error -show_entries format=duration,bit_rate -show_entries stream=codec_name,width,height,r_frame_rate input.mp4

Common Conversions

# MP4 (H.264 + AAC) — universal compatibility
ffmpeg -i input.mkv -c:v libx264 -preset medium -crf 23 -c:a aac -b:a 128k output.mp4

# WebM (VP9 + Opus) — web-optimized, smaller files
ffmpeg -i input.mp4 -c:v libvpx-vp9 -crf 30 -b:v 0 -c:a libopus -b:a 128k output.webm

# H.265/HEVC — 50% smaller than H.264 at same quality
ffmpeg -i input.mp4 -c:v libx265 -preset medium -crf 28 -c:a aac -b:a 128k output.mp4

# AV1 — best compression, slow encoding
ffmpeg -i input.mp4 -c:v libaom-av1 -crf 30 -b:v 0 -c:a libopus output.mkv

# Audio only (MP3)
ffmpeg -i input.mp4 -vn -c:a libmp3lame -q:a 2 output.mp3

# Audio only (high quality FLAC)
ffmpeg -i input.wav -c:a flac output.flac

Trim / Cut

# Trim from 00:01:30 for 60 seconds (fast, no re-encode)
ffmpeg -ss 00:01:30 -i input.mp4 -t 60 -c copy output.mp4

# Trim with re-encode (frame-accurate)
ffmpeg -i input.mp4 -ss 00:01:30 -to 00:02:30 -c:v libx264 -c:a aac output.mp4

Scale / Resize

# Scale to 1280x720 (maintain aspect ratio)
ffmpeg -i input.mp4 -vf "scale=1280:720:force_original_aspect_ratio=decrease,pad=1280:720:-1:-1" output.mp4

# Scale to 50%
ffmpeg -i input.mp4 -vf  output.mp4


ffmpeg -i input.mp4 -vf  output.mp4