media-processing

name	media-processing
description	FFmpeg + ImageMagick media processing. This skill should be used when transcoding video/audio, resizing/cropping images, HLS/DASH, thumbnails, batch ops, or hardware-accelerated pipelines.
license	MIT

Media Processing Skill

Process video, audio, and images using FFmpeg and ImageMagick for conversion, optimization, streaming, and manipulation.

When to Use This Skill

• Converting media formats (video, audio, images)
• Encoding video with codecs (H.264, H.265, VP9, AV1)
• Processing images (resize, crop, effects, watermarks)
• Extracting audio from video
• Creating streaming manifests (HLS/DASH)
• Generating thumbnails and previews
• Batch processing media files
• Hardware-accelerated encoding

Tool Selection Guide

Task	Tool
Video encoding/transcoding	FFmpeg
Audio extraction/conversion	FFmpeg
Live streaming (RTMP/HLS/DASH)	FFmpeg
Image resize/crop/convert	ImageMagick
Batch image processing	ImageMagick (mogrify)
Video thumbnails	FFmpeg
Image effects/watermarks	ImageMagick

Installation

# macOS
brew install ffmpeg imagemagick

# Ubuntu/Debian
sudo apt-get install ffmpeg imagemagick

# Windows
winget install ffmpeg
winget install ImageMagick.ImageMagick

# Verify
ffmpeg -version && ffprobe -version && magick -version

Quick Examples

# Convert format (stream copy, fast)
ffmpeg -i input.mkv -c copy output.mp4

# Re-encode with H.264
ffmpeg -i input.avi -c:v libx264 -crf 22 -c:a aac output.mp4

# Resize video to 720p
ffmpeg -i input.mp4 -vf scale=-1:720 -c:a copy output.mp4

# Extract audio
ffmpeg -i video.mp4 -vn -q:a 0 audio.mp3

# Image conversion
magick input.png -quality 85 -strip output.jpg

# Resize image
magick input.jpg -resize 800x output.jpg

# Square thumbnail
magick input.jpg -resize 200x200^ -gravity center -extent 200x200 thumb.jpg

# Batch resize
mogrify -path ./output -resize 800x -quality 85 *.jpg

# HLS stream
ffmpeg -i input.mp4 -c:v libx264 -preset fast -crf 22 \
  -f hls -hls_time 6 -hls_playlist_type vod playlist.m3u8

# Video GIF
ffmpeg -i input.mp4 -vf "fps=15,scale=640:-1:flags=lanczos,split[s0][s1];[s0]palettegen[p];[s1][p]paletteuse" output.gif

Key Parameters

FFmpeg Video

• -c:v — Video codec (libx264, libx265, libvpx-vp9)
• -crf — Quality (0-51, lower=better, 23=default)
• -preset — Speed/compression (ultrafast to veryslow)
• -b:v — Video bitrate (e.g., 2M, 2500k)
• -vf — Video filters

FFmpeg Audio

• -c:a — Audio codec (aac, mp3, opus)
• -b:a — Audio bitrate (e.g., 128k, 192k)
• -ar — Sample rate (44100, 48000)

ImageMagick Geometry

• 800x600 — Fit within (maintains aspect)
• 800x600! — Force exact size
• 800x600^ — Fill (may crop)
• 800x / x600 — Width or height only
• 50% — Scale percentage

Troubleshooting

FFmpeg "Unknown encoder"

ffmpeg -encoders | grep h264
sudo apt-get install libx264-dev libx265-dev

ImageMagick "not authorized"

# Edit /etc/ImageMagick-7/policy.xml
# Change rights="none" to rights="read|write" for the format

Memory errors

ffmpeg -threads 4 input.mp4 output.mp4
magick -limit memory 2GB -limit map 4GB input.jpg output.jpg

References

FFmpeg:

• ffmpeg/encoding-codecs.md — H.264, H.265, VP9, AV1, audio codecs, codec selection
• ffmpeg/encoding-quality.md — CRF, bitrate, presets, tune options, threading
• ffmpeg/encoding-hardware.md — NVIDIA NVENC, Intel QSV, AMD AMF, Apple VideoToolbox
• ffmpeg/filters-video.md — Scale, crop, rotate, overlay, denoise, color, text
• ffmpeg/filters-audio-advanced.md — Audio filters, complex filtergraphs, recipes
• ffmpeg/streaming-hls-dash.md — HLS, multi-bitrate HLS, DASH, encryption
• ffmpeg/streaming-live.md — RTMP platforms, screen capture, UDP/RTP, loop streams
• ffmpeg/streaming-thumbnails.md — Frame extraction, sprite sheets, preview generation

ImageMagick:

• imagemagick/editing-basics.md — Format conversion, resize, crop, thumbnails, rotation
• imagemagick/editing-effects.md — Blur, sharpen, color effects, borders, text, composition
• imagemagick/batch-basic.md — Mogrify, resize loops, format conversion, optimization
• imagemagick/batch-advanced.md — Parallel processing, watermarks, web pipelines, Python

Formats:

• format-compatibility/formats.md — Supported formats, codecs, platform compatibility tables
• format-compatibility/conversions.md — Common conversion commands, migration strategies

Resources

• FFmpeg: https://ffmpeg.org/documentation.html
• ImageMagick: https://imagemagick.org/