[FFmpeg-devel] [PATCH 3/3] lavc/aarch64: add hevc sao edge 8x8

J. Dekker jdek at itanimul.li
Tue May 17 14:53:16 EEST 2022


On 28 Apr 2022, at 21:50, Martin Storsjö wrote:

> [...]
> Compared with the previously applied (and reverted) patch, here, you previously had "mov x17, #4". I guess that'd mean the function only ever produced 8 output rows, while it now uses the real height parameter? Was this change a no-op (height is always 8?) or was this another hidden bug in the previous implementation?
>

Yes, this was another bug in a previous implementation which I've fixed in both of the newer versions.

>> [...]
>> +        sqxtun          v6.8b, v20.8h
>> +        sqxtun          v7.8b, v21.8h
>> +        st1             {v6.8b}, [ x0], x2
>> +        st1             {v7.8b}, [x16], x2
>> +        subs            x17, x17, #1
>
> This could be "subs w6, w6, #2" and you wouldn't need the lsr instruction at all. And you could place the subs before the two st1 instructions to reduce latency between them a little. (The same thing goes for moving subs further away from the branch that uses its outcome in the previous patch too.) But as this is just a reapply of a previously committed and reverted patch, I guess it's fine this way too...

Will do before apply if you're fine with it, not too complex change.

> The patchset otherwise looks good to me, modulo the question about the difference to the previous patchset above.

--
J. Dekker


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