[FFmpeg-devel] SIMD Motion Compensation Optimizations

[compn]

On Mon, 11 Nov 2024 14:07:21 +0000
AV Muppet via ffmpeg-devel <ffmpeg-devel at ffmpeg.org> wrote:

> On Monday, November 11th, 2024 at 3:12 AM, Rémi Denis-Courmont
> <remi at remlab.net> wrote:
> 
> > > I recently read a news article about impressive AVX-512
> > > optimizations of Motion Compensation functions and I'd like to
> > > learn more. Unfortunately, the article merely linked the post on
> > > X, which included a screenshot and little else.
> > > 
> > > https://x.com/FFmpeg/status/1852542388851601913  
> > 
> > That's a screenshot of dav1d's checkasm, so you'll find the code in
> > dav1d, not FFmpeg.  
> 
> Thanks for the pointer.
> 
> I'd like to alert folks that the only way I could reproduce
> performance numbers similar to theirs is when I built it with
> '-Dbuildtype=debug'. Otherwise, the SIMD versions are all within the
> typical order of magnitude vs. the generic C implementations you'd
> normally expect.
> 
> Again, I'm lacking any context concerning the original screen grab.
> However, the actual text of the tweet appears to be highly misleading.
> 
>     "A 94x speed improvement demonstrated using handwritten assembly"

are you trying to say that ffmpeg should take down the tweet?

well you can come on #ffmpeg-devel irc too, if you dont like twitter.

-compn