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FFmpeg's costly functions are all written in hand optimised assembly (twitter.com)

submitted 1 year ago by ray@lemmy.ml to c/opensource@lemmy.ml

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[-] stifle867@programming.dev 31 points 1 year ago

The logic is that it's much faster which is important for code that runs on a large portion of the world's devices. Pretty much anything to do with video is using ffmpeg. From a set top box, to your phone, computer, YouTube & Netflix, even on Mars.

Video processing is hard, and when you're processing that much data a x10 speedup is huge. That's why it's written in assembly. And there's really no downsides to it because the original implementation is in C (cross-platform), then there are handmade assembly versions for each specific platform (performance). Win-win.

[-] Heratiki@lemmy.ml 12 points 1 year ago

Not to mention size. Assembly is so incredibly small without all the code interpretation and library overhead. I remember some of the old warez scene exe’s for DOS that were a few kilobytes but ended up being a huge video quality intro. Some lasting minutes. Rather than a few seconds.

[-] intelati@programming.dev 7 points 1 year ago

Assembly is probably the closest thing to magic humans have ever created.

(I'm disqualifying String/Quantum as they are "theories" and not in common use)

[-] LinuxSBC@lemm.ee 1 points 1 year ago

sethboy66's response is very good, but I'll summarize it here in case it helps. In science, the word "theory" basically means "explanation." Some explanations are proven wrong, but others have a lot of evidence going for them. Quantum mechanics is a theory that's basically proven, and it's commonly used all the time, such as in the computer you used to write that comment. String theory is not really proven, but it's basically an extension to the existing body of quantum mechanics.