libjpeg-turbo VS Rustup

> all decoders will render the same pixels

Not true. Even just within libjpeg, there are three different IDCT implementations (jidctflt.c, jidctfst.c, jidctint.c) and they produce different pixels (it's a classic speed vs quality trade-off). It's spec-compliant to choose any of those.

A few years ago, in libjpeg-turbo, they changed the smoothing kernel used for decoding (incomplete) progressive JPEGs, from a 3x3 window to 5x5. This meant the decoder produced different pixels, but again, that's still valid:

https://github.com/libjpeg-turbo/libjpeg-turbo/commit/6d91e9...

Last vestiges of this fact AFAIK were libjpeg, which had a macro NEED_SHORT_EXTERNAL_NAMES that shortens all public identifiers to have unique 6-letter-long prefixes. Libjpeg-turbo nowadays has removed them though [1].

[1] https://github.com/libjpeg-turbo/libjpeg-turbo/commit/52ded8...

While I think the move to safer code through Rust and other alternatives is a nice breath of fresh air, I doubt you can get these kinds of optimization without using unsafe code in Rust. These optimized implementations often require some kind of safety-bypassing memory modifications to work as efficiently ad they do.

There's a reason https://github.com/libjpeg-turbo/libjpeg-turbo/tree/main/sim... is filled with assembly files with conditional loading.

Sure. You'll see it very often in codec implementations. From rav1e, a fast AV1 encoder mostly written in Rust: https://github.com/xiph/rav1e/tree/master/src/x86

Large portions of the algorithm have been translated into assembly for ARM and x86. Shaving even a couple percent off something like motion compensation search will add up to meaningful gains.

Or the current reference implementation of JPEG: https://github.com/libjpeg-turbo/libjpeg-turbo/tree/main/sim...

zune-jpeg is 1.5x to 2x faster than jpeg-decoder and is on par with libjpeg-turbo.

This is interesting from the standpoint of how new JVM features can be used to improve performance (what I presume the article's main purpose to have been), but the image processing improvement itself isn't head-turning. Also, we've found that libjpeg-turbo (https://libjpeg-turbo.org/) is ~5x (IIRC, can re-run my JMH benchmark if anyone wants me to) as fast for decoding JPEGs as ImageIO, so we wouldn't even benefit from this change in 21 much.

libjpeg-turbo: https://github.com/libjpeg-turbo/libjpeg-turbo/blob/main/simd/x86_64/jsimdcpu.asm

libjpeg-turbo

For all but the simplest formats (basically BMP), the difficulty of implementing encoding/decoding from scratch is significant - well beyond a beginner's ability, and challenging/time-consuming even for senior developers. So, libraries are used in practice - e.g. libpng and libjpeg-turbo.

I got it to finally work by following this

If you are someone actively using such relative-path toolchains, please contact us (Discord / Github issues).

We had a snap package; we removed it in mid 2022

I don't know. The PR references prior discussion without a link, so it may have been private.

As long as he doesn't put hidden folders in your root like rust. https://github.com/rust-lang/rustup/issues/341

I think you're being upvoted by folks who don't know better, which is a shame because you're making things up :/. The telemetry feature in rustup kept everything local and never "pinged home". And you had to enable it with a command `rustup telemetry enable`. And it just logged JSON files at the path you mentioned. By 2019, the feature was disabled (see: https://github.com/rust-lang/rustup/issues/341 ) because no one worked on it and it just gathered bugs.

FWIW, there is a proposal to add telemetry to LLVM [0] and Rust used to have telemetry [1], both off by default. Some things in the node.js world have telemetry enabled by default, like Next.js [3].

Some people are posting here as if this as already decided -- AFIACT, that's not the case. It's not even a formal proposal yet, and the stated intent was to start a conversation around something concrete. (For context, this is standard for how I've seen the Go project approaches large topics, including for example I think there were something like ~8 very detailed generics design drafts from the core Go team over ~10 years).

It sounds like the Go team is going to take some time to look into some of the alternative approaches suggested in the feedback collected so far.

In any event, this is obviously a topic people are very passionate about, especially opt-in vs. opt-out, but I guess I would suggest not giving up hope quite yet.

[0] https://discourse.llvm.org/t/rfc-lldb-telemetry-metrics/6458...

[1] https://github.com/rust-lang/rustup/issues/341

[2] https://nextjs.org/telemetry

Rust (Specifically Rust Up) seems to have planned to include telemetry but they paused and cancelled the decision, possibly after implementing it initially.

https://github.com/rust-lang/rustup/issues/341 and rust installation uses telemetry