Notices by Gianni Rosato (gianni@disobey.net)

I spoke with Julio Barba at VideoLAN Dev Days in London!

Here are our slides, discussing SVT-AV1-PSY: https://giannirosato.com/files/svt-av1-psy_vdd_2025.pdf

I'll find access to the video & post it soon!

#av1 #avif #ffmpeg #vdd

@eeeps thanks for the shout out, glad ur liking my work!!

Introducing oavif: faster target quality image compression

https://giannirosato.com/blog/post/oavif/

oavif can be up to 63% faster than traditional target quality encoders. Learn how in the attached blog post!

#av1 #avif #compression

fssimu2 has its first release! https://github.com/gianni-rosato/fssimu2/releases/tag/0.1.0

fssimu2 is a fast SSIMULACRA2 implementation in Zig, with support for distortion map output. It is ~23% faster than the reference implementation at ~40% less memory usage, while being 99.97% accurate. Give it a look if you're interested!

New Halide blog post!

https://halide.cx/blog/consistency

Quality and speed define an image encoder's compression performance. Consistency is a close third, and easily overlooked in image encoder design. What value does it provide, and how can we measure it?

#avif #webp #jxl #jpegxl #compression

Anyone using rss/atom readers can now type `giannirosato.com` into their reader to get my website's atom feed

I got to interview Julio Barba from Google for the Halide blog: https://halide.cx/blog/julio-barba-interview/

Go check it out if you're interested in what the next decade of multimedia tech might look like!

Completely redesigned my website with Zola (https://www.getzola.org) – check it out at https://giannirosato.com

Let me know if any links are broken if you link to my site – it should be fully backwards compatible with my old link hierarchy

Tune 3: Still Picture is coming to SVT-AV1: https://gitlab.com/AOMediaCodec/SVT-AV1/-/merge_requests/2489

Formerly Tune 4 in SVT-AV1-PSY. Thank you Julio!

Exciting #avif news – libaom’s tune iq (derived from SVT-AV1-PSY’s Tune 4) is used across The Guardian’s website now. They say they serve mostly AVIF, with JPEG XL shipped when supported. Very exciting stuff!

Improving AVIF in Open Source via the Halide blog

hav1 #aviflide.cx/blog/improving-avif-in-open-source/index.html

I wanted to write this to explain some of what went into Tune 4/Tune IQ, & help outline some of my reasoning for starting Halide Compression in the first place. I hope you enjoy!

#av1 #avif #encoding

@kornel Thank you! Hoping it will provide value for someone :)

The chroma subsampling is difficult … I’ve done a couple of things in Iris to mitigate its negative impact, but it remains a challenge.

As for testing, I think the most valuable test would be the one on the Iris webpage (https://halide.cx/iris/index.html).

Daala’s subset2 source images are all 4:2:0 which is unfortunate, but the numbers look similar with 4:4:4 subset1 (couldn’t find the same for subset2) favoring AVIF a bit.

@Schweinepriester Here’s a comparison to the latest libjxl release (green) among others. It is hard to compare libjxl sometimes, because it excels on really difficult images but often isn’t as good on average. Also, it is best in the high fidelity range, but we’re measuring from SSIMULACRA2 0-80 for BD-rate (meaning low through high fidelity, but not ultra-high)

@eeeps Jon is such an impressive inspiration in the field. Him & the other JXL authors are people every engineer should look up to.

Introducing Iris-WebP, a better WebP encoder: https://halide.cx/iris/index.html

Iris offers up to >20% better compression than libwebp, and trades blows with libaom for AVIF.

My goal is to build an image-first encoder ecosystem for the modern Web, so that new web image codecs aren't generally superfluous.

#av1 #webp #compression

"I designed my own ridiculously fast game streaming video codec – PyroWave"

https://themaister.net/blog/2025/06/16/i-designed-my-own-ridiculously-fast-game-streaming-video-codec-pyrowave/

Cool to see https://github.com/psy-ex/metrics in use in the wild, I'm glad it was useful!

Help restore the tax deduction for software dev in the US (Section 174)

https://news.ycombinator.com/item?id=44226145

If you live in the US and you've ever used a piece of software, you're probably interested in this. There's a sign-able letter attached.

Updated numbers for Eve-AV1 & Eve-VP9 are public! The last time they were updated was around 2019, so this should give a more relevant look at how they perform.

It takes a lot to improve a mature video encoder, and I'm very impressed with the Eve lineup.

#av1 #video #transcoding #encoding #codec #vp9

Ever-evolving, the latest GNOME desktop release brings a host of new features, including digital wellbeing tools, battery charge limiting, and support for HDR https://www.omgubuntu.co.uk/2025/03/gnome-48-best-new-features

#linux #foss #opensource #gnome

GNOME 48 is here!

https://release.gnome.org/48/

#GNOME