[FFmpeg-user] 4K RGB->YUV realtime conversion.

[Carl Eugen Hoyos]

Am Mo., 8. März 2021 um 23:32 Uhr schrieb Anders Degerberg
<anders at europasound.se>:
>
> On Mon, Mar 8, 2021 at 10:44 PM Carl Eugen Hoyos <ceffmpeg at gmail.com> wrote:
>
> > Just to make sure that our assumption that this would need
> > changes in libswscale is correct, please also test the following:
> > -pix_fmt yuv444p16 -vcodec rawvideo -an -f null -
> > -i "Decklink ..." -an -f null -
> > and compare the speed (or fps) indicator.
>
> Hi Carl Eugen,
>  thanks for looking into this, and my apologies for the top-posting mistake.
>
> - With pix_fmt yuv444p16 and rawvideo, auto_scaler engages, and I get
> 15fps/0.6x. One cpu thread at 100%, a few other threads around 10-20%.
> - Without changing pix_fmt, passing on the rgb data straight to null
> pipe, I get full framerate, 25fps/1x. One or two cpu-threads around
> 20-40%.

This shows that the assumption was correct, libswscale is the culprit.

Carl Eugen