[FFmpeg-devel] [PATCH 5/5] aarch64: me_cmp: Don't do uaddlv once per iteration

[Michael Niedermayer]

On Fri, Jul 15, 2022 at 10:56:03PM +0300, Martin Storsjö wrote:
> On Fri, 15 Jul 2022, Swinney, Jonathan wrote:
> 
> > If the max height is just 16, then this should be fine. I assumed that h
> > could have a much higher value (>1024), but if that is not the case,
> > then this is a useful optimization.
> 
> At least according to the me_cmp.h header, which says:
> 
> /* Motion estimation:
>  * h is limited to { width / 2, width, 2 * width },
>  * but never larger than 16 and never smaller than 2.
>  * Although currently h < 4 is not used as functions with
>  * width < 8 are neither used nor implemented. */

These rules where written with support for encoding of all
standard formats in mind at the time that was written.
today it may make sense to extend these rules to cover the
things which where created since then

thx

[...]
-- 
Michael     GnuPG fingerprint: 9FF2128B147EF6730BADF133611EC787040B0FAB

Republics decline into democracies and democracies degenerate into
despotisms. -- Aristotle
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