Gianni R
@giannirosato.com
Enhancing HDR on Instagram for iOS With Dolby Vision: https://engineering.fb.com/2025/11/17/ios/enhancing-hdr-on-instagram-for-ios-with-dolby-vision/ #av1 #vp9 #hdr
November 22, 2025 at 9:20 AM
Enhancing HDR on Instagram for iOS With Dolby Vision: https://engineering.fb.com/2025/11/17/ios/enhancing-hdr-on-instagram-for-ios-with-dolby-vision/ #av1 #vp9 #hdr
I spoke with @juliobbv.bsky.social at VideoLAN Dev Days in London!
Here are our slides, discussing SVT-AV1-PSY: giannirosato.com/files/svt-av...
I'll find access to the video & post it soon!
Here are our slides, discussing SVT-AV1-PSY: giannirosato.com/files/svt-av...
I'll find access to the video & post it soon!
giannirosato.com
November 4, 2025 at 5:13 PM
I spoke with @juliobbv.bsky.social at VideoLAN Dev Days in London!
Here are our slides, discussing SVT-AV1-PSY: giannirosato.com/files/svt-av...
I'll find access to the video & post it soon!
Here are our slides, discussing SVT-AV1-PSY: giannirosato.com/files/svt-av...
I'll find access to the video & post it soon!
Introducing oavif: faster target quality image compression
giannirosato.com/blog/post/oa...
oavif can be up to 63% faster than traditional target quality encoders. Learn how in the attached blog post!
#av1 #avif #compression
giannirosato.com/blog/post/oa...
oavif can be up to 63% faster than traditional target quality encoders. Learn how in the attached blog post!
#av1 #avif #compression
Introducing oavif | Gianni Rosato
oavif is a new approach to target quality encoding in image compression, designed around smarter convergence strategies and quicker scoring to be as fast as possible.
giannirosato.com
October 12, 2025 at 6:41 PM
Introducing oavif: faster target quality image compression
giannirosato.com/blog/post/oa...
oavif can be up to 63% faster than traditional target quality encoders. Learn how in the attached blog post!
#av1 #avif #compression
giannirosato.com/blog/post/oa...
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! github.com/gianni-rosat...
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!
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!
Release 0.1.0 · gianni-rosato/fssimu2
First release! 🎉 Check README for more information.
What's Changed
generate LUT at compile time by @damster101 in #1
Zig 0.15.1 by @gianni-rosato in #3
feat: remove all simd in favor of scalar imp...
github.com
October 3, 2025 at 6:48 AM
fssimu2 has its first release! github.com/gianni-rosat...
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!
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!
halide.cx/blog/consist...
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
halide.cx/blog/consist...
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
Measuring Image Encoder Consistency | Halide Compression
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?
halide.cx
September 15, 2025 at 10:07 PM
New Halide blog post!
halide.cx/blog/consist...
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
halide.cx/blog/consist...
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
The Halide Compression website (halide.cx) now has an Atom feed – just paste the URL into your favorite RSS reader and you should be good to go!
Measuring Image Encoder Consistency | Halide Compression
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?
halide.cx
September 15, 2025 at 10:06 PM
The Halide Compression website (halide.cx) now has an Atom feed – just paste the URL into your favorite RSS reader and you should be good to go!
Reposted by Gianni R
New blog post about my experiences using spark.js with three.js:
www.ludicon.com/castano/blog...
Re-posts and feedback appreciated!
www.ludicon.com/castano/blog...
Re-posts and feedback appreciated!
three.js + spark.js – Ignacio Castaño
www.ludicon.com
September 9, 2025 at 7:42 AM
New blog post about my experiences using spark.js with three.js:
www.ludicon.com/castano/blog...
Re-posts and feedback appreciated!
www.ludicon.com/castano/blog...
Re-posts and feedback appreciated!
Anyone using rss/atom readers can now type `giannirosato.com` into their reader to get my website's atom feed
August 30, 2025 at 3:53 AM
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: halide.cx/blog/julio-b...
Go check it out if you're interested in what the next decade of multimedia tech might look like!
Go check it out if you're interested in what the next decade of multimedia tech might look like!
An Interview With Julio Barba | Halide Blog
halide.cx
August 29, 2025 at 10:42 PM
I got to interview Julio Barba from Google for the Halide blog: halide.cx/blog/julio-b...
Go check it out if you're interested in what the next decade of multimedia tech might look like!
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 (www.getzola.org) – check it out at 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
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
Zola
Everything you need to make a static site engine in one binary.
www.getzola.org
August 29, 2025 at 8:12 PM
Completely redesigned my website with Zola (www.getzola.org) – check it out at 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
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
Reposted by Gianni R
The “AV1 is a disaster” myth
Here’s what’s actually true:
- SVT-AV1 is fast, fully multithreaded and packed with SIMD.
- It scales beautifully on modern CPUs.
- It beats x264, x265, and VP9 in bitrate vs runtime.
AV1 on CPU isn’t a disaster. It’s quietly winning.
Here’s what’s actually true:
- SVT-AV1 is fast, fully multithreaded and packed with SIMD.
- It scales beautifully on modern CPUs.
- It beats x264, x265, and VP9 in bitrate vs runtime.
AV1 on CPU isn’t a disaster. It’s quietly winning.
August 1, 2025 at 2:28 AM
The “AV1 is a disaster” myth
Here’s what’s actually true:
- SVT-AV1 is fast, fully multithreaded and packed with SIMD.
- It scales beautifully on modern CPUs.
- It beats x264, x265, and VP9 in bitrate vs runtime.
AV1 on CPU isn’t a disaster. It’s quietly winning.
Here’s what’s actually true:
- SVT-AV1 is fast, fully multithreaded and packed with SIMD.
- It scales beautifully on modern CPUs.
- It beats x264, x265, and VP9 in bitrate vs runtime.
AV1 on CPU isn’t a disaster. It’s quietly winning.
Tune 3: Still Picture is coming to SVT-AV1: #note_2704093242704093242" class="hover:underline text-blue-600 dark:text-sky-400 no-card-link" target="_blank" rel="noopener" data-link="bsky">https://gitlab.com/AOMediaCodec/SVT-AV1/-/merge_requests/2489#note_2704093242
Formerly Tune 4 in SVT-AV1-PSY. Thank you @juliobbv.bsky.social !
Formerly Tune 4 in SVT-AV1-PSY. Thank you @juliobbv.bsky.social !
August 22, 2025 at 6:11 PM
Tune 3: Still Picture is coming to SVT-AV1: #note_2704093242704093242" class="hover:underline text-blue-600 dark:text-sky-400 no-card-link" target="_blank" rel="noopener" data-link="bsky">https://gitlab.com/AOMediaCodec/SVT-AV1/-/merge_requests/2489#note_2704093242
Formerly Tune 4 in SVT-AV1-PSY. Thank you @juliobbv.bsky.social !
Formerly Tune 4 in SVT-AV1-PSY. Thank you @juliobbv.bsky.social !
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! Thanks @juliobbv.bsky.social!
![“[sorry for the spam] Just wanted to say that theguardian.com is on `tune=iq` for the last two weeks (we serve AVIF to non-JXL-supporting browsers) and we couldn’t be more happy. Encoder consistency is much, much higher (still not as good as JXL, but that’s just an impression, not a rigorous assessment): some highly compressible images where delicate detail was being obliterated grown even ~3× in filesize and look much better while unnecessarily weighty images shrank, mostly without any perceptible degradation. Interestingly, we kept the same quality values (which differ by dpr) and as much as we can say, the overall bandwidth stayed more or less the same (I can’t see any change in the graph), so it’s likely the massive reduction of rare weighty images offset small images growing.
Huge thanks to juliobbv for his work on `tune=iq` and to whomever else worked on it. And to friends at our image CDN (Fastly). And to everyone here as without this server, I wouldn’t even know about it…
As always, we welcome improvements to any and all encoders. So the idea of “splitting Julio” couldn’t sound more exciting 😉.”](https://cdn.bsky.app/img/feed_thumbnail/plain/did:plc:lj7y6n7ouwe2276ubo5cizaa/bafkreiabxrmpl67iegnifzu64fdckai6yjodzjneksoknqebyndshcjila@jpeg)
July 30, 2025 at 8:46 PM
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! Thanks @juliobbv.bsky.social!
Reposted by Gianni R
New post! After my previous post about image compression, a few people asked me to try different encoder settings. So I went ahead and tested a couple of them :)
www.rachelplusplus.me.uk/blog/2025/07...
www.rachelplusplus.me.uk/blog/2025/07...
A Better Image Compression Comparison - Rachel++
www.rachelplusplus.me.uk
July 19, 2025 at 6:13 PM
New post! After my previous post about image compression, a few people asked me to try different encoder settings. So I went ahead and tested a couple of them :)
www.rachelplusplus.me.uk/blog/2025/07...
www.rachelplusplus.me.uk/blog/2025/07...
Improving AVIF in Open Source via the Halide blog
halide.cx/blog/improvi...
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
halide.cx/blog/improvi...
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
Improving AVIF in Open Source | Halide Blog
halide.cx
July 14, 2025 at 3:50 AM
Improving AVIF in Open Source via the Halide blog
halide.cx/blog/improvi...
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
halide.cx/blog/improvi...
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
Introducing Iris-WebP, a better WebP encoder: halide.cx/iris/index.h...
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.
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.
July 9, 2025 at 5:44 PM
Introducing Iris-WebP, a better WebP encoder: halide.cx/iris/index.h...
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.
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.
Reposted by Gianni R
AV1 @ Scale: Film Grain Synthesis, The Awakening
netflixtechblog.com/av1-scale-fi...
netflixtechblog.com/av1-scale-fi...
AV1 @ Scale: Film Grain Synthesis, The Awakening
Unleashing Film Grain Synthesis on Netflix and Enhancing Visuals for Millions
netflixtechblog.com
July 3, 2025 at 2:48 PM
AV1 @ Scale: Film Grain Synthesis, The Awakening
netflixtechblog.com/av1-scale-fi...
netflixtechblog.com/av1-scale-fi...
Reposted by Gianni R
The world’s largest digital camera — which will create an unparalleled map of the night sky — is at the heart of the new Vera C. Rubin Observatory in Chile. Here’s how it works. nyti.ms/4n8OpgP
June 19, 2025 at 7:43 PM
The world’s largest digital camera — which will create an unparalleled map of the night sky — is at the heart of the new Vera C. Rubin Observatory in Chile. Here’s how it works. nyti.ms/4n8OpgP
"I designed my own ridiculously fast game streaming video codec – PyroWave"
themaister.net/blog/2025/06...
Cool to see github.com/psy-ex/metrics in use in the wild, I'm glad it was useful!
themaister.net/blog/2025/06...
Cool to see github.com/psy-ex/metrics in use in the wild, I'm glad it was useful!
I designed my own ridiculously fast game streaming video codec – PyroWave – Maister's Graphics Adventures
themaister.net
June 17, 2025 at 6:11 AM
"I designed my own ridiculously fast game streaming video codec – PyroWave"
themaister.net/blog/2025/06...
Cool to see github.com/psy-ex/metrics in use in the wild, I'm glad it was useful!
themaister.net/blog/2025/06...
Cool to see github.com/psy-ex/metrics in use in the wild, I'm glad it was useful!
Reposted by Gianni R
New blog post: I've spent the last couple of months building a tool to compare different image encoders, and wrote an article about some of the things you need to consider to get reliable results. I also talk a bit about how JPEG-XL is looking promising!
www.rachelplusplus.me.uk/blog/2025/06...
www.rachelplusplus.me.uk/blog/2025/06...
Evaluating image compression tools - Rachel++
www.rachelplusplus.me.uk
June 13, 2025 at 12:05 AM
New blog post: I've spent the last couple of months building a tool to compare different image encoders, and wrote an article about some of the things you need to consider to get reliable results. I also talk a bit about how JPEG-XL is looking promising!
www.rachelplusplus.me.uk/blog/2025/06...
www.rachelplusplus.me.uk/blog/2025/06...
Help restore the tax deduction for software dev in the US (Section 174)
news.ycombinator.com/item?id=4422...
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.
news.ycombinator.com/item?id=4422...
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.
Tell HN: Help restore the tax deduction for software dev in the US (Section 174) | Hacker News
news.ycombinator.com
June 10, 2025 at 5:04 AM
Help restore the tax deduction for software dev in the US (Section 174)
news.ycombinator.com/item?id=4422...
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.
news.ycombinator.com/item?id=4422...
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.
Reposted by Gianni R
May have bitten off quite a lot with this next blog post, but the goal is in sight! Basically built an encoder comparison tool from scratch, to really nail down the details in my own mind. Should have some interesting things to say soon - think of it as a "yes, and" to Gianni's excellent post:
Comparing Video Encoders
Comparing video encoders is easy, but not often done correctly.
giannirosato.com
May 26, 2025 at 10:27 AM
May have bitten off quite a lot with this next blog post, but the goal is in sight! Basically built an encoder comparison tool from scratch, to really nail down the details in my own mind. Should have some interesting things to say soon - think of it as a "yes, and" to Gianni's excellent post:
Reposted by Gianni R
Lil' teaser for an upcoming blog post, building on my last post (www.rachelplusplus.me.uk/blog/2025/03...): This graph compares compressing an image at a single fixed resolution (dotted curve) vs. encoding at multiple resolutions, netflix style (solid curve):
May 21, 2025 at 3:25 AM
Lil' teaser for an upcoming blog post, building on my last post (www.rachelplusplus.me.uk/blog/2025/03...): This graph compares compressing an image at a single fixed resolution (dotted curve) vs. encoding at multiple resolutions, netflix style (solid curve):