FFmpeg School of Assembly Language • Hacker News Board

Re: FFmpeg School of Assembly Language

#11

Post by agumonkey » Sat, Feb 22, 2025, 5:52 PM UTC

I remember kempf saying most of recent development on codecs is in raw asm. Only logical that they can write some tutorials :)

Re: FFmpeg School of Assembly Language

#12

Post by hagbard_c » Sat, Feb 22, 2025, 5:52 PM UTC

do_not_redeem wrote: post #5

netr0ute wrote: post #2

The only thing I don't like about this is the focus on x86 assembly, which is a sinking ship because RISC-V is coming to eat its lunch, FAST.

How would you define "fast"?

In relative terms, compared with similarly priced and powered devices on the market. RISC-V does lag behind the others - ARM, x86/64 - here, at least for now.

Re: FFmpeg School of Assembly Language

#13

Post by henning » Sat, Feb 22, 2025, 5:53 PM UTC

This is what Hacker News should be about. Awesome. Thank you.

Re: FFmpeg School of Assembly Language

#14

Post by [deleted] » Sat, Feb 22, 2025, 5:53 PM UTC

netr0ute wrote: post #2

The only thing I don't like about this is the focus on x86 assembly, which is a sinking ship because RISC-V is coming to eat its lunch, FAST.

[deleted]

Re: FFmpeg School of Assembly Language

#15

Post by pdyc » Sat, Feb 22, 2025, 5:54 PM UTC

xuhu wrote: post #8

"Assembly language of FFmpeg" leads me to think of -filter_complex. It's not for human consumption even once you know many of its gotchas (-ss and keyframes, PTS, labeling and using chain outputs, fading, mixing resolutions etc). But then again no-one is adjusting timestamps manually in batch scripts, so a high-level script on top of filter_complex doesn't have much purpose.

what do you mean by no purpose? you can adjust them programmatically in batch scripts.

Re: FFmpeg School of Assembly Language

#16

Post by snvzz » Sat, Feb 22, 2025, 5:57 PM UTC

do_not_redeem wrote: post #5

netr0ute wrote: post #2

The only thing I don't like about this is the focus on x86 assembly, which is a sinking ship because RISC-V is coming to eat its lunch, FAST.

How would you define "fast"?

Not eating. Only drinking water or zero calory drinks such as black coffee.

Only while fasting can a person think clearly. When thinking clearly, RISC-V is inevitably chosen as the ISA.

Fasting will also eventually make you hungry. Thus "RISC-V is coming to eat its lunch, FAST."

Re: FFmpeg School of Assembly Language

#17

Post by philip22 » Sat, Feb 22, 2025, 5:57 PM UTC

[dead]

Re: FFmpeg School of Assembly Language

#18

Post by imglorp » Sat, Feb 22, 2025, 6:00 PM UTC

Asm is 10x faster than C? That was definitely true at some point but is it still true today? Have compilers really stagnated so badly they can't come close to hand coded asm?

Re: FFmpeg School of Assembly Language

#19

Post by lukaslalinsky » Sat, Feb 22, 2025, 6:01 PM UTC

This is perfect. I used to know the x86 assembly at the time of 386, but for the more advanced processors, it was too complex. I'd definitely like to learn more about SIMD on recent CPUs, so this seems like a great resource.

Re: FFmpeg School of Assembly Language

#20

Post by jki275 » Sat, Feb 22, 2025, 6:03 PM UTC

imglorp wrote: post #18

Asm is 10x faster than C? That was definitely true at some point but is it still true today? Have compilers really stagnated so badly they can't come close to hand coded asm?

Probably some very niche things. I know I can't write ASM that's 10x better than C, but I wouldn't assume no one can.