Alchemist Overview
Alchemist scans your media library, analyzes every file, and decides whether transcoding it would actually save meaningful space. If a file is already efficiently compressed, it skips it and tells you exactly why in plain English. If it can save space without hurting quality, it encodes it — using whatever hardware you have — automatically, while you sleep.
Your originals are never touched until the new file passes quality validation. Nothing is deleted until you say so.
What it does
- Scans configured library directories and queues files for analysis
- Runs FFprobe on each file to extract codec, resolution, bitrate, and HDR metadata
- Applies BPP (bits-per-pixel) analysis and size thresholds to decide whether transcoding is worth it
- Selects the best available encoder automatically (NVIDIA NVENC, Intel QSV, AMD VAAPI/AMF, Apple VideoToolbox, CPU fallback)
- Encodes to AV1, HEVC, or H.264 based on your configured target
- Validates output quality (optional VMAF scoring) before promoting the result
- Tells you exactly why every skipped file was skipped
- Supports named API tokens for automation clients and external observability
- Can be served under a path prefix such as
/alchemist - Includes an experimental single-file Conversion / Remux workflow
- Expands Library Intelligence beyond duplicate detection into storage-focused recommendations
What it is not
Alchemist is not Tdarr. There are no flow editors, no plugin stacks, no separate services to install. It is a single binary that does one thing without asking you to become an FFmpeg expert.
Hardware support
Alchemist detects and selects the best available hardware encoder automatically (NVIDIA NVENC, Intel QSV, AMD VAAPI/AMF, Apple VideoToolbox, or CPU fallback).
For detailed codec support matrices (AV1, HEVC, H.264) and vendor-specific setup guides, see the Hardware Acceleration documentation.
Where to start
| Goal | Start here |
|---|---|
| Get it running | Installation |
| Docker setup | Docker |
| Get your GPU working | Hardware |
| Automate with tokens | API |
| Understand skip decisions | Skip Decisions |
| Tune per-library behavior | Profiles |
Nightly builds
docker pull ghcr.io/bybrooklyn/alchemist:nightly
Published on every push to main that passes Rust checks.
Version format: 0.3.0-dev.3-nightly+abc1234.
Stable: ghcr.io/bybrooklyn/alchemist:latest
License
GPLv3. Free to use, modify, and distribute under the same license. Genuinely open source — not source-available.