[padenot]

I (Firefox developer working on anything media related) got in contact with the dev on Twitter, and he told me that Web Codecs was missing (and we're shipping this in a month or so, it's been in Nightly for some time), and something to save project file to disk (https://developer.mozilla.org/en-US/docs/Web/API/Window/show...).

So I spoofed the user-agent in a nightly build here on my Linux desktop workstation, then had to alias one method that we should have implemented years ago but only have with a `moz` prefix (`HTMLMediaElement.mozCaptureStream`). This is on us to fix.

Then it looks like a worker script is served with the `Content-Type` `text/html` instead of `application/javascript` or something like that. We also have a pref flip to bypass that check, so I did that, but this is on the dev to fix.

When you do this it works, I've loaded project demos containing videos, audio, various things composited on top, scrubbed the timeline aggressively in a debug build, moved things around in various bits of the interface and also in the rendering frame, etc., things seem to work as they should, perf is as I'd expect it to be (and again, I'm running it in a debug build with optimizations disabled for anything media related, enabled for other parts of the browser).

What's missing is `window.showSaveFilePicker` and file system related stuff. It's possible to use https://developer.mozilla.org/en-US/docs/Web/API/File_System... instead (that we ship, e.g. Photoshop on the Web uses it). We think that it's much less scary than giving access to the file system to a content process of a Web browser. Maybe because videos can sometimes be extremely big files, direct access to the FS could be of use there. Thankfully, we also ship extremely modern video encoders to make them tiny instead, but that's currently a limitation Firefox has, for better or worse.

https://paul.cx/public/pikimov-firefox-nightly.webm

[nicoburns]

I would really like to be able to give webpages access to a real local file/folder. It's one of the main barriers to using web apps as production apps and is IMO one of the drivers pushing everything into (generally proprietary, locked in) cloud storage.

Obviously the permissioning model needs to be thought out here. It could perhaps only be available to "PWA"s that have been "installed", only on https sites, and only once explicit permission has been given, etc.

But it's so cumbersome to have upload/download be the only way to sync files into a web app.

[clementpiki]

Wow, so you do have a workaround for the missing window.showSaveFilePicker, that's promising!

[jesup]

Probably the dev needs to use a different method to save (effectively download), much as Adobe Photoshop does when it exports files on Firefox. Not hard to do at all. Likely the same for reading files, if this tool needs that.

OPFS provides high-speed read and write for temporary files and non-exported files; again this is what Photoshop uses. There is a 10GB limit per domain currently. I'm not sure this particular app actually needs that, though

[justinclift]

Aren't you replying to the dev? ;)

[jesup]

padenot already has

[mrandish]

Thanks for taking the time to investigate what's currently the gap with FF. As a long-time Firefox user, I'm hoping you can guide this dev regarding ways to get things working from his end while also using this app's needs to inform FF improvements from your end.

[perk]

Thanks, I have some of the same issues with FF on www.render.video - will look into this ASAP :)