Force conversion of images to WebP (or other efficient formats) on upload

[barelyprofessional]

It'd be nice to have an option to force conversion of uploaded images to WebP or similar modern image formats (e.g. AVIF). Reason is that PNGs are unbelievably large and users with default ShareX configs will be filling the server up with these fatty PNGs as that's the default config.

For now I'm considering forcing image compression by injecting x-zipline-image-compression-percent into the user's HTTP request when it's not specified, but it'd be nice to have the option of maintaining lossless images while not having them be horrendously large.

Edit: I've concocted a truly abominable "workaround". Basically using HAProxy I'm injecting the compression header but only if the form body has a .png file extension, with the option for the user to opt out using a special header.

This is how my HAProxy config looks if someone is interested in stealing this idea

Regarding set-var, you probably don't need that for this exercise and can just look at the path in the request. The only reason I'm using it is because it is necessary to preserve the original path for deciding whether to send the Cache-Control headers as zipline doesn't send these for images.

frontend www-in
    [...]
    http-request set-var(txn.path) path

backend zipline
    option http-buffer-request
    acl image_path var(txn.path) -m beg /u/
    acl upload_path var(txn.path) -m beg /api/upload
    acl compression_ext req.body -m reg filename=".+\.png"
    acl no_compression hdr(x-no-compression) -m found
    http-request add-header x-zipline-image-compression-percent 95 if !no_compression upload_path compression_ext
    http-response add-header Cache-Control max-age=604800 if image_path
    server ziplineserver serveraddy:3000 check

The option http-buffer-request is necessary to inspect the request body but it'll have memory implications given you're telling HAProxy to wait for the whole request to come in before doing something. That being said, it wasn't as dramatic as I expected for my instance, HAProxy is using < 100 MB even when a large upload is happening.

[diced]

seems like a good idea! i've got stuff in the works that should let you do this, as well as configure what format you want to use when compressing (jpeg, webp, jxl, even png compression idrk how it works but sharp takes care of it lol) along with this, it would probably be a good idea to let you configure what format video thumbnails are stored in, since it defaults to jpeg as well.

[diced]

now added, 95042e1...ac37f13 along with the thumbnail generation stuff i mentioned!