av1-avif VS libavif

The article is about avif not webp. Note the editors for the AOM avif specification don't even include Google https://aomediacodec.github.io/av1-avif/

This reminds me of something similar from the guy who implemented AVIF in Firefox. He gives a talk about the implementation [1] where he talks about the CLAP privacy problem. Basically the spec adds a field that allows for cropping of the image, but the binary file would still contain the original. This would lead users to believe some image data was deleted when it really wasn't. I always thought he spent a lot of time and effort on this for little gain, but now I'm starting to think it was worth his effort.

[1]: https://youtu.be/BUkRlfkv2D8?t=2199

And the related GitHub issue: https://github.com/AOMediaCodec/av1-avif/issues/188

So actually the same images I linked above are in the AOMediaCodec repo as well, under Link-U: https://github.com/AOMediaCodec/av1-avif/tree/master/testFiles/Link-U And I see the same issue with the yuv422 images there as well. I'm guessing Apple's AVIF implementation must be incomplete?

Created by Alliance for Open Media and worked on by Netflix, Microsoft, and Google developers, AVIF is open source - you can even weigh in on image processing and spec issues.

I've been trying to find a way edit 14bit RAW files (.ARW) to an HDR capable format (HEIF/AVIF). In the process I found out there's an official AVIF encoder (1) by AOM that seems like it should be capable of creating HDR PQ stills.

Others samples are available here : https://github.com/AOMediaCodec/av1-avif/tree/master/testFiles/Netflix/avif

AVIF can do something that resembles hierarchical JPEG and that could be useful for progressive decoding: you can have multiple layers/scales, where e.g. first a 1:4 image is encoded, then residuals to get to 1:2, then residuals to get to 1:1. Examples of this were recently added to the AVIF spec: https://github.com/AOMediaCodec/av1-avif/pull/134

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).

libavif is at version 0.11.1, see https://github.com/AOMediaCodec/libavif/tags