Hi, On Wed, May 29, 2024 at 3:44 PM Wu Jianhua <toq...@outlook.com> wrote:
> Ronald S. Bultje: > > On Wed, May 29, 2024 at 11:38 AM <toq...@outlook.com<mailto: > toq...@outlook.com>> wrote: > > +%else > > + vpunpcklqdq m11, m2, m2 > > + vpunpckhqdq m12, m2, m2 > > + vpunpcklwd m11, m11, m14 > > + vpunpcklwd m12, m12, m14 > > + paddd m0, m11 > > + paddd m1, m12 > > + packssdw m0, m0, m1 > > +%endif > > > [..] > > Also, the whole thing just emulates a saturated add. Can't you use paddsw > instead of paddw and be done with it? To add to Andreas' question: is > saturating here normatively required? > > We didn't have any sample that failed for this issue except for the > checksum with specific seeds. I think we can keep not changing it until a > real sample has something wrong. > > @Nuomi to get more details. > I think "just" replacing paddw with paddsw is correct, since the input pixels are 12bit (so they could be either unsigned or signed), the filtered output is the result of packssdw (so signed words), and the desired output is 12bit pixels anyway, anything greater than that is clipped to 12bit range. So to me, it seems paddsw is a cheaper way to accomplish the same thing. Ronald _______________________________________________ ffmpeg-devel mailing list ffmpeg-devel@ffmpeg.org https://ffmpeg.org/mailman/listinfo/ffmpeg-devel To unsubscribe, visit link above, or email ffmpeg-devel-requ...@ffmpeg.org with subject "unsubscribe".
