[FFmpeg-devel] avfilter/x86/vf_blend : add avx2 version for 8b func (WIP)

Henrik Gramner henrik at gramner.com
Sun Dec 17 20:41:49 EET 2017


On Thu, Dec 14, 2017 at 11:16 AM, Martin Vignali
<martin.vignali at gmail.com> wrote:
> 2017-12-13 17:37 GMT+01:00 Henrik Gramner <henrik at gramner.com>:
>> You could also do vextracti128 + 128-bit packuswb instead of 256-bit
>> packuswb + vpermq.
>>
> Sorry don't understand this part
> do you mean 128 bit packuswb + movh for each lane ?
> or something else ?

packuswb      m0, m0
vpermq        m0, m0, q3120

vs.

vextracti128 xm1, m0, 1
packuswb     xm0, xm1

Uses a 128-bit op instead of a 256-bit one which is generally
preferable whenever possible.


More information about the ffmpeg-devel mailing list