The associated issue for comparing two u16s is interesting.

https://github.com/rust-lang/rust/issues/140167

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Oh this stuff is what’s prompting the ffmpeg Twitter account to make a stand against Rust https://x.com/ffmpeg/status/1924137645988356437?s=46 Show 3 replies

Intersting to see this article on the perfromance advantage of not having to zero buffers after this article 2 days ago: https://news.ycombinator.com/item?id=44032680

Title undersells post; it’s actually 2.3% faster with two good optimizations. Show 1 reply

Good post! The inefficient code for comparing pairs of 16-bit integers was an interesting find. Show 1 reply

All being equal codecs ought to be in WUFFS† rather than Rust, but I can well imagine that it's a much bigger lift to take something as complicated as dav1d and write the analogous WUFFS than to clean up the c2rust translation, if you said a thousand times harder I'd have no trouble believing that. I just think it's worth it for us as a civilisation.

† Or an equivalent special purpose language, but WUFFS is right there

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Haha I was just thinking to myself "I wonder if anyone made any progress on that rav1d bounty yet?"

You know it's a good post when it starts with a funny meme. Seems related to the recent discussion: $20K Bounty Offered for Optimizing Rust Code in Rav1d AV1 Decoder (memorysafety.org) | 108 comments | https://news.ycombinator.com/item?id=43982238 Show 2 replies

Honestly its a little surprising the first optimization he found was something fairly obvious just by using perf. I thought they had discussed the zeroing buffers issue in the first post? The second optimization was definitely more involved/interesting but was still pointed at by perf. Don't underestimate that tool! Show 2 replies

This is really fun. Is there anything stopping rustc from performing the transmute trick ?

Edit: If I had read the next paragraph, I'd have learn about [1] before commenting

[1] https://github.com/rust-lang/rust/issues/140167

AV1 continues to be the most fascinating development in media encoding.

AVG-SVT-PSY is particularly interesting to read up on as well.

Beautiful work and nice write-up. Profiling and optimization is absolutely my favorite part of software development.

Is skipping initialization of buffers a hard problem for compilers? Show 4 replies

I don't understand this project. dav1d is 99% assembly (x86_64/risc-v 64bits/etc) with very little simple and plain C as coordinating code. Show 1 reply

I am very curious what you did to embed the profiler results into your blog post. Literally copy the HTML nodes? Show 1 reply

There's something about real optimization stories that I find fascinating – particularly the detailed ones including step-by-step improvements and profiling to show how numbers got better. In some way, they are satisfying to read.

Nicholas Nethercote's "How to speed up the Rust compiler" writings[1] fall into this same category for me.

Any others?

[1] https://nnethercote.github.io/

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AV1 is an amazing codec. I really hope it replaces proprietary codecs like h264 and h265. It has a similar, if not better, performance to h265 while being completely free. Currently on an Intel-based Macbook it is only supported in some browsers, however it seems that newer video cards from AMD, Nvidia, and Intel do include hardware decoders. Show 5 replies