Lord1Egypt Media Compression Skill
Compress and convert images and videos with intelligent defaults. Supports single files and batch processing.
Supported Formats
Images: JPG, PNG, WebP, BMP, TIFF, GIF → JPG, PNG, WebP Videos: MP4, MOV, AVI, MKV, WebM, FLV, WMV, M4V → MP4
Prerequisites
ffmpeg must be installed:
- Ubuntu/Debian:
sudo apt update && sudo apt install ffmpeg - macOS:
brew install ffmpeg - Windows: Download from https://ffmpeg.org/download.html and add to PATH
Verify installation: ffmpeg -version
Quick Start
Image Compression
# Compress to target size (auto-adjusts quality)
python scripts/compress_image.py photo.jpg --max-size 200kb
# Resize + compress
python scripts/compress_image.py photo.png --width 800 --output photo_small.jpg
# Convert to WebP (better compression)
python scripts/compress_image.py photo.jpg --format webp
# Batch compress entire folder
python scripts/compress_image.py ./photos --output ./compressed --quality 80
# Preview mode - see what will happen without compressing
python scripts/compress_image.py photo.jpg --max-size 500kb --preview
# Keep backup of original file
python scripts/compress_image.py photo.jpg --max-size 500kb --backup
Video Compression
# Compress with default settings (good balance)
python scripts/compress_video.py video.mp4 --output video_small.mp4
# Resize to 720p
python scripts/compress_video.py video.mp4 --height 720
# Target specific file size (approximate)
python scripts/compress_video.py video.mp4 --target-size 50mb
# Lower quality for smaller file
python scripts/compress_video.py video.mp4 --crf 28
# Batch process all videos in folder
python scripts/compress_video.py ./videos --output ./compressed --height 480
# Preview mode - see what will happen without compressing
python scripts/compress_video.py video.mp4 --height 720 --preview
# Keep backup of original file
python scripts/compress_video.py video.mp4 --height 720 --backup
Common Use Cases
1. Upload to Website (Image)
Most websites need images under 500KB:
python scripts/compress_image.py photo.jpg --max-size 500kb --format webp
2. Email Attachment (Image)
Email often has 25MB limit:
python scripts/compress_image.py scan.pdf.jpg --max-size 5mb --quality 90
3. Social Media Video
Platforms prefer 720p, smaller files:
python scripts/compress_video.py clip.mov --height 720 --crf 23 --preset fast
4. Archive Old Videos
Maximum compression for storage:
python scripts/compress_video.py old_video.avi --crf 28 --preset slow --height 480
5. Convert Format Only
Keep quality, just change format:
# Image
python scripts/compress_image.py image.png --format jpg --quality 95
# Video
python scripts/compress_video.py video.mov --output video.mp4 --crf 18
Parameters Reference
Image (compress_image.py)
| Parameter | Description | Default |
|---|---|---|
input |
Input file or directory (required) | - |
--output, -o |
Output file or directory | Auto-generated |
--max-size |
Target max file size (e.g., 500kb, 2mb) | None |
--quality, -q |
JPEG/WebP quality (1-100) | 85 |
--width, -w |
Max width in pixels | Original |
--height |
Max height in pixels | Original |
--format, -f |
Output format: jpg, png, webp | Original format |
--no-strip |
Keep metadata (default: remove) | False |
--preview, -p |
Preview mode: show settings without compressing | False |
--backup, -b |
Keep backup of original file | False |
Video (compress_video.py)
| Parameter | Description | Default |
|---|---|---|
input |
Input file or directory (required) | - |
--output, -o |
Output file or directory | Auto-generated |
--crf |
Quality 0-51 (lower=better). 18=visually lossless, 23=default, 28=smaller | 23 |
--preset |
Encoding speed: ultrafast, superfast, veryfast, faster, fast, medium, slow, slower, veryslow | medium |
--height |
Max height (480, 720, 1080) | Original |
--target-size |
Approximate target size (e.g., 50mb, 1gb) | None |
--fps |
Limit frame rate (e.g., 30, 24) | Original |
--audio-bitrate |
Audio quality (e.g., 128k, 192k) | 128k |
--preview, -p |
Preview mode: show settings without compressing | False |
--backup, -b |
Keep backup of original file | False |
Quality Guidelines
Images
- 90-95: High quality, minimal compression artifacts
- 85: Sweet spot (default) - good quality, significant size reduction
- 70-80: Acceptable for web, smaller files
- 50-60: Low quality, visible artifacts
Videos (CRF)
- 17-18: Visually lossless, archival quality
- 20-22: High quality, professional use
- 23: Default, good balance (recommended)
- 28: Smaller files, acceptable quality
- 35+: Low quality, preview/draft only
Presets
- ultrafast: Fastest encoding, largest files
- fast: Quick results, slightly larger
- medium: Default balance
- slow: Better compression, smaller files
- veryslow: Maximum compression, smallest files
Batch Processing
When input is a directory:
- All supported files are processed
- Output directory structure mirrors input
- Progress shown for each file
- Original and compressed sizes displayed
Example:
$ python scripts/compress_image.py ./vacation_photos --output ./compressed --max-size 500kb
找到 24 个图像文件
[1/24] 处理: IMG_001.jpg
✓ 2847.3KB → 456.2KB (84.0% 减少)
[2/24] 处理: IMG_002.png
✓ 1532.1KB → 298.5KB (80.5% 减少)
...
Troubleshooting
"ffmpeg not found"
Install ffmpeg first:
# Ubuntu/Debian
sudo apt update && sudo apt install ffmpeg
# macOS
brew install ffmpeg
"Permission denied"
Make scripts executable:
chmod +x scripts/*.py
Quality too low
Increase quality setting:
# Image
python scripts/compress_image.py photo.jpg --quality 90
# Video
python scripts/compress_video.py video.mp4 --crf 20
File not smaller
- Try lower quality or smaller dimensions
- Some files are already optimally compressed
- Use
--max-sizeto force target size
Batch processing stops
Check that all files in directory are valid images/videos. Corrupt files may cause errors.
Advanced Tips
- Strip metadata for privacy (default behavior)
- Use WebP for best web compression
- 720p height is usually enough for mobile viewing
- CRF 23 + preset slow gives great results for archiving
- Test with one file before batch processing
References
- FFmpeg Guide - Detailed ffmpeg commands and parameters