libavif VS sumatrapdf

> Have you seen this more recent data that includes AVIF? https://cloudinary.com/labs/cid22

The graph from Cloudinary uses libaom to do the encoding at speed preset 7 (s7), which is far from speed preset 0 and disables many AVIF coding tools. I do not know why this was chosen by the author, but it does not reflect AVIF performance. According to https://github.com/AOMediaCodec/libavif/issues/440#issuecomm... speed preset 8 loses 20-35% compression efficiency.

It's 2023, surely this is not yet another bug related to memory unsafety that could be avoided if we'd stop writing critical code that deals with extremely complex untrusted input (media codecs) in memory unsafe languages?

Yep, of course it is: https://github.com/webmproject/libwebp/commit/902bc919033134...

I guess libwebp could be excused as it was started when there were no alternatives, but even for new projects today we're still committing the same mistake[1][2][3].

[1] -- https://code.videolan.org/videolan/dav1d

[2] -- https://github.com/AOMediaCodec/libavif

[3] -- https://github.com/AOMediaCodec/libiamf

Yep. Keep writing these in C; surely nothing will go wrong.

As far as I understand you are talking about this plugin. I don't know c++ and half of the code was like a black magic, but if I get it correctly, it encodes your images with libavif, and adds custom metadata ([solar/time of day] -> json -> base64).

So a few dozen comments, but so far it doesn't look like any mention the immediate thing that jumped out at me which was the claims vs AVIF:

>"In turn, what users will be given is yet another facet of the web that Google itself controls: the AVIF format."

Huh? I'll admit I haven't been following codecs as super ultra closely as I used to, but I thought AOM was a pretty broad coalition of varying interests and AV1 an open, royalty free codec that was plenty open source friendly? I've heard plenty of reasonable arguments that JPEG XL has some real technical advantages over AVIF and as well as superior performance is much more feature rich and scalable. So I could see people being bummed for that. But this is the first time I've heard the assertion that it's somehow a Google project? I mean, AOM's libavif reference is BSD too [0]? I'd love some more details on that from anyone who has been following this more closely. I can even understand if AOM isn't as community friendly and an accusation that it's dominated by big corps, but in that case why single out Google alone? From wiki:

>The governing members of the Alliance for Open Media are Amazon, Apple, ARM, Cisco, Facebook, Google, Huawei, Intel, Microsoft, Mozilla, Netflix, Nvidia, Samsung Electronics and Tencent.

Like, Google is certainly significant, but that's a lot of equally heavy hitters. And interesting that Mozilla is there too.

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0: https://github.com/AOMediaCodec/libavif

> You have a good point that AVIF layered image items can act like such P/B-frames. Do libavif (or other AVIF implementations if any) make use of them?

Seemingly. As search for "libavif progressive encoding" shows several issues about this, and a search for "progressive" in https://github.com/AOMediaCodec/libavif/blob/main/include/av... shows an enum for avifProgressiveState, appears to show support for it.

I mean, it already has it: https://github.com/AOMediaCodec/libavif/commit/570c42c2c10a878c8cc896f1c5daf1a955274142

Apart from mpv and ffplay, the only software I currently have installed that can play animated AVIF is Chromium. And from what I've read from this libavif bug report, I'm not sure if looping animated files in general is something that's just done by default by a lot of software regardless of whether the file is marked as a loop or not.

The support for progressive AVIF decoding has landed in libavif and in Chromium. But are there any docs on how to create and test progressive AVIF images?

The "for example" is the key here, because AVIF does support multi-layer coding per the spec now (though not currently implemented in libavif from what I can tell).

I’m curious, have you tried SumatraPDF (uses muPDF under the hood)?

https://github.com/sumatrapdfreader/sumatrapdf

Do you mind reporting those issues either to SumatraPDF at https://github.com/sumatrapdfreader/sumatrapdf/issues or directly to MuPDF at https://bugs.ghostscript.com/ if it also has the same issue? Thank you!

There are many wonderfully weird PDFs and epubs out there, but we do our best to fix issues. :)

FWIW, https://github.com/sumatrapdfreader/sumatrapdf/issues/1249 ("Support form filling for at least 1040 irs form") has a comment saying "MuPDF-GL has the capability to edit fields and save the PDF" of a 1040.

I have just learned the Firefox 93 added support XFA - https://techdows.com/2021/10/open-xfa-pdfs-in-firefox.html .

So it would appear there are free software solutions to XFA forms.

Just because something doesn't seem far-fetched to you, doesn't mean most people will regard it as far-fetched.

Many people all sorts of "sectarian objections" - far more than there are SovCits or other tax protesters. Stallman has never come across as a tax protester. Ergo, I think it's far-fetched that "sectarian objections" is strongly associated with tax protests.

Further, at https://stallman.org/archives/2017-may-aug.html we can read Stallman opinine that we need to "return to the "bad old days", when Americans in general could have a decent life, not penury; when the US could afford to build what the public needed instead of privatizing everything with a toll" by making taxation more progressive. At https://stallman.org/archives/2011-jan-apr.html we read he supports "The Fairness in Taxation Act [which] would raise taxes to 45% on incomes over a million dollars a year."

link for the lazy

If you are going to run something in wine, try sumatrapdf. It's FOSS but Windows only. (sadly, but runs great on wine)

Sumatra is Adobe free, free, and can remember the page you were on.

Sumatra PDF has always been my choice: minimal, lightweight, no bloat... just perfect!