[FFmpeg-devel] [PATCH v2] swscale/output: Altivec-optimize float yuv2plane1

[Carl Eugen Hoyos]

2018-12-16 10:06 GMT+01:00, Lauri Kasanen <cand at gmx.com>:
> This function wouldn't benefit from VSX instructions, so I put it
> under altivec.
>
> ./ffmpeg_g -f rawvideo -pix_fmt rgb24 -s hd1080 -i /dev/zero -pix_fmt
> grayf32le \
> -f null -vframes 100 -v error -nostats -
>
> 3743 UNITS in planar1,   65495 runs,     41 skips
>
> -cpuflags 0
>
> 23511 UNITS in planar1,   65530 runs,      6 skips
>
> grayf32be
>
> 4647 UNITS in planar1,   65449 runs,     87 skips
>
> -cpuflags 0
>
> 28608 UNITS in planar1,   65530 runs,      6 skips
>
> The native speedup is 6.28133, and the bswapping one 6.15623.

> Fate passes

I wonder a little how, given that grayf32 already breaks fate as-is...

Note that this function / this pix_fmt currently has no real use-case
afaict.

Carl Eugen