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[directfb-users] Pixel format conversion and Different pixel formats for windows

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  • Subject: [directfb-users] Pixel format conversion and Different pixel formats for windows
  • From: Selwyn Tang <>
  • Date: Fri, 21 Nov 2003 16:39:13 +0800
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Hi all,

It seems to me that a RGB16 image cannot be rendered to a YUY2 surface. Looking at rgba_to_dst_format(), I found the conversion from RGBA to YUY2 not implemented. But there are macros at src/gfx/convert.h converting RGB to YUV (Y/CB/CR_FROM_RGB). Why is it not implemented? Is it because of the calculations required rather than the simple bit-shifts among RGBs?

Another problem is that I cannot play a video on a YUY2 window surface, which is, in turn, on an ARGB layer. The error message is "only copying blits supported for YUV in software" at generic.c line 3311. I guess there should be no problem playing the video to a YUY2 surface. There should be no conversion required and the performance should be better. Since that surface is on an ARGB layer, is it also not implemented to blit the YUY2 surface on an ARGB layer? Strange enough, I have no problem playing the video to an ARGB window surface on an ARGB layer.

When playing back an mpeg-1 file using libmpeg3, I find 3 threads running, two of which takes up 50% and 40% of the cpu time on my epia-m C3 1G system. Is such huge cpu usage due to pixel format conversions? Or is it due to the mpeg decoding? How can I tell?

Thanks in advance!


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