imgproxy for jellyfin

[dilyo]

Why?
- Wanted to test it, and use some imgproxy options
- Jellyfin felt sometimes slow with larger images
- imgproxy uses libvips know to be very fast/efficient

Downside
- Complexity

Upside
- fast
    - Uncached/cold 600 ms vs 80 ms (30 images from 500 2000ms vs )
    - Cached 10 ms vs 0-1ms (30 images 10-15ms vs 0-1ms)
- Max image size
- easy nginx cache
 
Setup
- jellyfin
- nginx with -f to check file path (tried auth_digiest, but never got retrun header in nginx, feels like a bug in nginx)
- small proxy with readonly on jellyfin.db to resolve urls
- imgproxy container
- Storage /var/lib/jellyfin/metadata

Modes code to GitHub, because forum code formation is awful
https://github.com/jfhacks/jellyfin-imgproxy

Just wanted t share it, because I looked for something like this and found nothing.

[TheDMV]

I've been complaining about the large image sizes for years now, to no avail. The default jpg compression is set to 96, which makes huge images. Going to 45-75 would make a big difference - but this works too.

[dilyo]

Yeah, noticed images are so heavy on slower clients and high-res images are slow with Jellyfin resize. Also, it enforces some limits and formats + quality.

Moved it to GitHub, because code blocks are pain.
https://github.com/jfhacks/jellyfin-imgproxy

Used it only for myself so far, so docu is mixed at best. But it should work.

[User 22046]

Ahh cache replacement, neat!

[dilyo]

I tried a lot of things at thought at the end, I should maybe post it. Last changes are just simplifying some things.

About space
Jellyfin will always generate a new image if modifiers are set (size, format, or quality), so you would need to configure a passthough to save on storage.
A lot of images are larger than 4k or above 8k or even 10k and sending optimal image to client speeds it up a lot or raster SVG, so client needs no SVG support.
Also, I can use JXL, AVIF besides WebP.

To be clear, imgproxy won't touch original images. It is a replacement for /var/cache/jellyfin/images/resized-image with more features and control (in case some requests slip though → report it). As described, it can unify quality over all client, because those are depended on the dev. Some go with 100%, others with 80% and some artifacts lover set 35% or so.