Dummond D. Slow (mental.delete@this.protozoa.us) on November 18, 2020 9:21 am wrote:
> Maynard Handley (name99.delete@this.name99.org) on November 18, 2020 9:13 am wrote:
> >
> > x264 in SPEC is not there to help you decide which PC to buy for ripping DVD content!
> > It is there as an exemplar of certain styles of code: various generic compression techniques
> > (so lots of bit by bit manipulation) and various image analysis techniques (so searches
> > over images and image comparisons at various frequency granularities).
> >
>
> You didn't read it? If x264 is example of a kind of code, it is an example of code
> heavily optimised with multimedia (integer) SIMD. It's a greeat example or maybe
> too great, other codebases like ffmpeg or x265 will be a bit less optimized.
>
> If you want to explore such code, run it with assembly. It has assembly for ARM too, and not that
> little of it. Without SIMD, it is the opposite of example of multimedia compression code.

The main interest of that code is its high IPC and potential automatic vectorization, not
that it exhibits absolute fastest code for h264 compression.

The mistake is to think that since it's named x264 it should behave as the x264 you know. An
understandable mistake, I agree.

> "Various generic compression techniques", my butt. This is an area I
> know, so please don't talk armchair nonsense like you did just now.

Keeping it civil is an option, you know?