english/.opencode/skills/media-processing/references/common-workflows.md

Common Media Processing Workflows

Video Optimization

Optimize for Web

# H.264 with good compression
ffmpeg -i input.mp4 \
  -c:v libx264 -preset slow -crf 23 \
  -c:a aac -b:a 128k \
  -movflags +faststart \
  output.mp4

Multi-Pass Encoding

# Pass 1 (analysis)
ffmpeg -y -i input.mkv -c:v libx264 -b:v 2600k -pass 1 -an -f null /dev/null

# Pass 2 (encoding)
ffmpeg -i input.mkv -c:v libx264 -b:v 2600k -pass 2 -c:a aac output.mp4

Hardware-Accelerated Encoding

# NVIDIA NVENC
ffmpeg -hwaccel cuda -i input.mp4 -c:v h264_nvenc -preset fast -crf 22 output.mp4

# Intel QuickSync
ffmpeg -hwaccel qsv -c:v h264_qsv -i input.mp4 -c:v h264_qsv output.mp4

Extract Video Segment

# From 1:30 to 3:00 (re-encode for precision)
ffmpeg -i input.mp4 -ss 00:01:30 -to 00:03:00 \
  -c:v libx264 -c:a aac output.mp4

Image Workflows

Create Responsive Images

# Generate multiple sizes
for size in 320 640 1024 1920; do
  magick input.jpg -resize ${size}x -quality 85 "output-${size}w.jpg"
done

Batch Image Optimization

# Convert PNG to optimized JPEG
mogrify -path ./optimized -format jpg -quality 85 -strip *.png

Complex Image Pipeline

# Resize, crop, border, adjust
magick input.jpg \
  -resize 1000x1000^ \
  -gravity center \
  -crop 1000x1000+0+0 +repage \
  -bordercolor black -border 5x5 \
  -brightness-contrast 5x10 \
  -quality 90 \
  output.jpg

GIF Creation

Video to GIF

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

Animated GIF from Images

# Create with delay
magick -delay 100 -loop 0 frame*.png animated.gif

# Optimize size
magick animated.gif -fuzz 5% -layers Optimize optimized.gif

Background Removal Workflows

Batch Background Removal

# Process all images in directory
for img in *.jpg; do
  rmbg "$img" -m modnet -o "${img%.jpg}-no-bg.png"
done

Product Photography

# 1. Remove background
rmbg product.jpg -m u2net-cloth -o product-no-bg.png

# 2. Resize to multiple sizes
magick product-no-bg.png -resize 800x800 product-800.png
magick product-no-bg.png -resize 400x400 product-400.png

# 3. Add white background if needed
magick product-no-bg.png -background white -flatten product-white-bg.jpg

Media Analysis

Inspect Video Properties

# Detailed JSON output
ffprobe -v quiet -print_format json -show_format -show_streams input.mp4

# Get resolution
ffprobe -v error -select_streams v:0 \
  -show_entries stream=width,height \
  -of csv=s=x:p=0 input.mp4

Image Information

# Basic info
identify image.jpg

# Detailed format
identify -verbose image.jpg

# Custom format
identify -format "%f: %wx%h %b\n" image.jpg