[Libav-user] Fast colourspace conversion on iOS

[Paul B Mahol]

On Sat, Jul 17, 2021 at 1:50 PM Nicolas George <george at nsup.org> wrote:

> Nuno Santos (12021-07-17):
> > I’m using libav to mux a video file at full hd.
> >
> > At some point I need to convert the original frame at 1920x1080 RGB to
> YUV420P
> >
> > This requires sws_scale to be called. On desktop it takes around 7/8 ms
> to convert a frame. On iOS it takes 28 ms.
> >
> > I guess sws_scale is not optimised for iOS. How is people doing it on
> iOS then?
>
> I do not think that sws_scale requires OS-specific optimizations.
>

This is not correct at all. libswscale have some neon assembly. Dunno how
user compiles libraries, or maybe neon asm is very old.


>
> What are the CPUs of your desktop and mobile devices?
>
> Regards,
>
> --
>   Nicolas George
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