XSF Discussion - 2022-09-07

a probably very stupid question. looking at https://datatracker.ietf.org/doc/html/draft-schmaus-kitten-sasl-ht-07 what does `initiator-hashed-token := HMAC(token, "Initiator" || cb-data)` mean? || is a concatination so the bytes for cb-data the string "Initiator" are just added to the bytes of "Initiator" - but what does `token,` mean? isn’t that another concatination? or in other words what is the difference between` token || "Initiatior" || cb-data` and `token, "Initiatior", cb-data`

HMAC takes a key and a message

So, one is `token`, the other is `"Initiator" || cb-data`. Good luck guessing which is which! :)

oh ok. I thought it's just hash(…)

No, it's two hashes in series with some padding and stuff.

but yeah that makes sense. thank you

https://en.wikipedia.org/wiki/Hmac#Definition but your crypto library really should provide it

Hi. What would be the recommanded image format nowadays in a XEP for lossy compression of images (mostly photos)? I'm thinking mostly about patent issues. Is JPEG OK to use? WebP?

goffi, JPEG is still the only one with widespread support sadly. :(

WebP is often not an improvement over JPEG, and then you have formats like AVIF which are, but with exactly no support on mobile.

There are JPEG features you should avoid if you’re worried about patents, but most implementations don’t support them anyway, so if you stay with JPEG Baseline you’re good.

Alright, thanks Link Mauve

If you know your recipient is on either Windows or Linux, AVIF is an option.

Otherwise, use JPEG.

Link Mauve: it's for a protoXEP, thus is should be available on as most plateform as possible, thus I'll go with JPEG

JPEG for photo for sure I think. WebP for everything else (stickers, animations, etc)

I think most Linux distributions still don’t ship with WebP support out of the box.

I’d recommend PNG and GIF instead, if you want widespread support.

It's ok Linux users are used to things being broken until they install the right stuff :D

I mean, WebP works in Firefox on Debian Stable

it's not exactly new

PNG can't animate, APNG never got good support, and GIF looks like garbage, so for animations especially WebP is very nice

singpolyma, Firefox uses it explicitly, but most XMPP clients (AFAIK) are not web clients.

singpolyma, for large animations you want a video format anyway.

Sure, the clients may need to add support, will depend on how they are rendering images etc

WebP *is* a video format, luckily :)

Actually no.

What linux desktop client supports inline gif even?

moparisthebest: I'm not aware of one

It’s using VP8 for its lossy compression, but only supports keyframes so you will get much bigger files if only small parts change frame-to-frame.

moparisthebest, any based on GTK I think?

Not Dino I think

last time I checked, Dino 0.3 use VP8

trung.fun, video calls in Dino go through Gstreamer, while image decoding goes through gdk-pixbuf.

Two different libraries with different support for different formats.

Dino supports gif fine, it just restricts itself to displaying the first frame only. Same for all other animated image formats that gdk pixbuf supports.

pixbuf does support animated images, but who would want those to be actually animated?

<3

👀

Also, for anything that is not a video, just use animated svg please! Much smaller files and even scale perfectly to every screen resolution and hidpi devices

Yes!

Also, mobile client devs, please add support.

<iframe> is what you're looking for, with animated CSS

I can do css animations on svg without iframes

that's how all animations in gtk are done already 🙂

I'd be happy to use animated SVG if I'm authoring something new, just depends on the kind of content

One of the issue that I have with stickers and animated stickers is more getting nice content for me, so finding artists that can craft content that I can package in my client

This is why stickers must come in packs from a sticker store where you buy them so you can pay the artists!!

Thus we must launch XMPPCoin!

I'm happy to pay the artist, but yeah there's so many sticker images around on the web I'm not sure if making more is the priority? But I guess it all depends on users and what they need

I’d really like to have a sticker pack using animated SVG, but almost all of my contacts are using Android which doesn’t support this format. :(

It doesn’t even support normal SVG, not even SVG Tiny…

there are libraries for it I'm sure

Sure, but how many additional MiB are you ready to ship with your application?

Just ship a full browser!

For such a fringe feature, which is fringe because you don’t.

> Two different libraries with different support for different formats. I don't know what it does underneath, but it takes nearly half a minute to launch.

Guys, if u want wide adoption as quickly as u can, stick with jpeg, png and gif. You can come back and upgrade all them codec later. (I would be quite impressed if you make a client that has support for Apple Prores444 but hey) Anyway, I think lets not create more issues for the people who want to try xmpp for the first time.

edhelas: do you have ideas of stickers you'd like to see, or you just want to hand a budget to an artist and ask them to go nuts?

> Just ship a full browser! That's the spirit ↺

I already did that a few times in Movim

The sticker XEP opts for a kind of distributed sticker storage fed by the users… so, if that's supported, you just scrape signalstickers.com (they have a python library), and unleash Sticker Hell™️.

millesimus: yes, for sure. lots of places we can get them from

on android the users can also get sticker packs right in their keyboard

Iirc, Samsung allows you to combine emojis to create stickers. Quite funny.

millesimus, suddenly, Spore?

https://mailarchive.ietf.org/arch/msg/tools-discuss/YZi7Ea5ppodpjZxhyFTZB-AflNc/

Boo IETF

At least they're not moving to discord?

I honestly didn't know there were IETF channels