FORMATS was mp4/webm/mp3/image2 — a web-delivery list, because that is what av-club was first for. a right-click on a .mkv that offers "mp4 or webm" is not a conversion tool, so: mkv, mov for video; m4a, flac, wav, ogg, opus beside mp3 for audio. the KEY is what a caller asks for; `container` is what ffmpeg is told, because ffmpeg's names for two of them are not what anybody calls them — `matroska` for .mkv, `ipod` for .m4a. making a caller know that is making them learn ffmpeg trivia to convert a file. audio encoders too: libmp3lame, libvorbis, flac, alac, pcm_s16le beside aac and libopus, plus q:a for the encoders that want a quality rather than a bitrate, and map_metadata/id3v2_version so tags survive a conversion. A REAL BUG FOUND ON THE WAY, and it had shipped. `an` was declared as an enum whose only value was "1", so it emitted `-an 1` — and `-an` takes no argument, so ffmpeg read the `1` as an output filename and died with "Error opening output files: Invalid argument", naming neither the option nor the problem. `an` had never worked. I reproduced it exactly by adding `vn` the same way. so there is a `flag` kind now: given `true` it emits the option alone, and anything else is refused with a message that says so. `vn: "1"` is a 400 rather than a mystery. verified through the running service: mkv remux, mov, and extraction to all six audio formats — mp3, flac, wav, ogg, opus, m4a — all 200. Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>
av-club
Turning whatever someone uploads into assets a website can actually serve.
People upload photos and videos straight off a phone or a camera: a 12 MB HEIC, a 4K clip in a codec Safari refuses to play, a JPEG carrying the GPS coordinates of the room it was shot in. None of that belongs on a page as-is. This is the thing in between.
It is an HTTP service that exposes as much of sharp, ffmpeg and ffprobe as can be exposed safely, keeping each tool's own vocabulary — sharp operations are named what sharp names them, ffprobe fields come back spelled the way ffprobe spells them. If you know the tool, you know the API.
What it will not let you do is name a file. That single restriction is what makes the rest safe to
open up; see docs/SECURITY.md.
Status
Assets, probing and the full sharp surface work. ffmpeg is designed but not built — that is the next piece.
docs/API.md |
The HTTP surface — start here if you are calling it |
docs/SHARP.md |
Every sharp operation and its bounds. Generated from the validator, so it cannot drift |
docs/SECURITY.md |
The threat model and the invariants. Read before adding an endpoint |
docs/TOOLING.md |
What is installed, and the two things that bite |
docs/PIPELINE.md |
What this is for, and what is still undecided |
Quick start
./scripts/install.sh # system packages + bun deps, then verifies
cp .env.example .env # then set AV_CLUB_TOKEN
bun dev
Verified on Ubuntu 24.04. The installer says so rather than guessing if it finds something else.
# upload something, then resize it
curl -X POST localhost:3020/v1/assets -H "Authorization: Bearer $AV_CLUB_TOKEN" -F file=@photo.jpg
curl -X POST localhost:3020/v1/sharp -H "Authorization: Bearer $AV_CLUB_TOKEN" \
-H 'Content-Type: application/json' -d '{
"input": "as_…",
"pipeline": [{ "rotate": {} }, { "resize": { "width": 1200, "withoutEnlargement": true } }],
"output": { "format": "avif", "options": { "quality": 55 } }
}'
bun run verify checks the tooling; bun run docs regenerates docs/SHARP.md from the validator.
Why this is its own repo
It has system dependencies a web app should not have to assume. ffmpeg, ImageMagick, libvips and
exiftool are a real installation, not an npm install. Keeping them here means a consuming project
can state that it needs this, rather than quietly failing on a machine that happens not to have
ffprobe on its PATH.
It changes on a different clock. Encoder settings, derivative sizes and format choices get revisited as browser support moves. Page templates and database schemas do not.
Nothing about it is specific to one site. Resizing an image and extracting a poster frame are the same problem everywhere, which is why this is not buried inside the project that first needed it.
Its first consumer
fofos/platform — a website with a public site, an admin, and a database. Admins upload media
through the admin; this processes it; the platform stores what comes back.
How that handoff works is not decided yet. The honest options are a library the platform imports,
a CLI it shells out to, or a service it talks to. Each has real consequences for deployment and for
whether processing blocks an admin's upload while they wait. That question is written down in
docs/PIPELINE.md as open, rather than being answered by whatever happens to get built first.
Working agreements
- Commit and push every turn that changes anything — working, broken, or half-finished. The history is the artifact; it is how decisions stay traceable and mistakes stay learnable.
- Docs are live documents, and the code is the source of truth. Docs move with the code in the same commit. A doc contradicting the code is a bug in the doc.
- Direction changes fast, and that is expected. Nothing written here is frozen.