README
¶
shrink
A high-performance media optimization tool written in Go. shrink automatically transcodes video, audio, images, and ebooks into modern, space-efficient formats like AV1, Opus, and AVIF. It can also recursively extract and process files within archives.
Supported formats
- Video: Transcodes to AV1 (using SVT-AV1) in an MKV container.
- Audio: Transcodes to Opus.
- Images: Converts to AVIF (using ImageMagick).
- Ebooks: Optimizes EPUB/PDF files by compressing internal images and cleaning CSS (using Calibre).
- Archives: Recursively extracts and processes contents of ZIP, RAR, 7z, and more (using unar).
Features
- Smart Filtering: Only processes files if the estimated savings meet your configured thresholds.
- Parallelism: Concurrent processing of different media types.
- Database Support: Integrates with SQLite databases to track and manage media state.
- Video game / EXE mangler: This will help you cut down on your video game habit by mangling your EXE archives that contain video game resources in common formats by converting them into something that the video game doesn't expect and so it will probably crash!
Installation
Ensure you have Go installed, then run:
go install -tags fts5 github.com/chapmanjacobd/shrink/cmd/shrink@latest
External Dependencies
shrink relies on several industry-standard tools for media processing. Ensure these are installed and available in your PATH:
| Tool | Required For |
|---|---|
| FFmpeg | Video and Audio transcoding |
| ImageMagick | Image conversion (specifically magick) |
| Calibre | Ebook conversion (ebook-convert) |
| unar | Archive extraction (unar and lsar) |
| ocrmypdf | (Optional) OCR for PDF files |
OS-Specific Installation Notes
Fedora/RHEL:
- ImageMagick requires the
ImageMagick-heicpackage for HEIC/AVIF support:sudo dnf install ImageMagick-heic
macOS:
- Calibre may require Rosetta 2 on Apple Silicon if the installed version is not yet native:
softwareupdate --install-rosetta
Ubuntu/Debian:
- FFmpeg may need the
ffmpeg-extraspackage for full codec support (e.g., H.265, AV1):sudo apt install ffmpeg-extras
Quick Start
Basic Usage
Shrink all media in a directory:
shrink .
Advanced Examples
Process only video files and move successful transcodes to a specific directory:
shrink --video-only --move ./optimized_videos /path/to/media
Shrink files while requiring at least 20% space savings for video:
shrink --min-savings-video=20% /path/to/media
Dry run to see what would be processed:
shrink --simulate /path/to/media
Only transcode during specific hours (e.g., overnight 10pm-6am):
shrink --active-time 10pm-6am /path/to/media
Multiple active periods (lunch and evening):
shrink --active-time 12pm-1pm --active-time 6pm-11pm /path/to/media
CLI Reference
Global Flags
| Flag | Description | Default |
|---|---|---|
| -v, --verbose | Enable verbose logging | false |
| --simulate | Dry run; don't actually modify files | false |
| -y, --no-confirm | Don't ask for confirmation before starting | false |
| --video-threads | Maximum concurrent video transcodes | 2 |
| --video-4k-threads | Maximum concurrent video transcodes for 4K+ resolution videos | 1 |
| --audio-threads | Maximum concurrent audio transcodes | 4 |
| --image-threads | Maximum concurrent image conversions | 8 |
| --text-threads | Maximum concurrent text conversions | 2 |
Optimization Flags
| Flag | Description | Default |
|---|---|---|
| --min-savings-video | Minimum savings for video (e.g., "10%" or "50MB") | 5% |
| --min-savings-audio | Minimum savings for audio | 10% |
| --min-savings-image | Minimum savings for images | 15% |
| --preset | SVT-AV1 preset (0-13, lower is slower/better) | 7 |
| --crf | CRF value for SVT-AV1 (0-63, lower is higher quality) | 40 |
| --max-video-height | Maximum video height | 960 |
| --max-video-width | Maximum video width | 1440 |
Filter Flags
| Flag | Description |
|---|---|
| --video-only | Only process video files |
| --audio-only | Only process audio files |
| --image-only | Only process image files |
| --text-only | Only process text/ebook files |
| -s, --include | Include paths matching pattern |
| -E, --exclude | Exclude paths matching pattern |
Schedule Flags
| Flag | Description |
|---|---|
| --active-time | Only transcode if estimated finish time falls within active period. Supports multiple time ranges. Accepts 12-hour (2pm, 8:30am) and 24-hour (14:00, 23:30) formats. |
Schedule Examples
Only process during evening/night hours:
shrink --active-time 6pm-8am /path/to/media
Process during lunch break and evening:
shrink --active-time 12pm-1pm --active-time 6pm-10pm /path/to/media
Using 24-hour format:
shrink --active-time 11:30-23:00 /path/to/media
License
This project is licensed under the BSD 3-Clause License. See the LICENSE file for details.
Directories
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| Path | Synopsis |
|---|---|
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cmd
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shrink
command
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internal
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commands
Package commands implements the CLI commands and orchestration logic for the shrink application.
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Package commands implements the CLI commands and orchestration logic for the shrink application. |
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db
Package db provides database access for archive analysis cache.
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Package db provides database access for archive analysis cache. |
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ffmpeg
Package ffmpeg provides wrappers for FFmpeg and FFprobe operations.
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Package ffmpeg provides wrappers for FFmpeg and FFprobe operations. |
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models
Package models defines the core data structures used throughout the application.
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Package models defines the core data structures used throughout the application. |
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testutils
Package testutils provides helper functions and types for testing the shrink application.
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Package testutils provides helper functions and types for testing the shrink application. |
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