[Libav-user] NV12->RGB24 vs YUV420P->RGB24

[Alex]

I've been working on implementing hardware decoder integration. While 
things generally are working, there's not much gain: the color 
conversion from NV12 seems to be dramatically more expensive than from 
the YUV420P in case of software decoder.

When profiling, I'm seeing YUV420P->RGB24 using yuv420_rgb24_mmxext 
(which barely registers in profiler), while NV12->RGB24 using 
yuv2rgb24_X_c, which takes a fairly dramatic amount of time.

Is that something that is expected? A known problem? Or perhaps 
something is wrong on my side of things?

Using n4.2.2.