[GEM-dev] [pix_video]: issue with swapped colors

[Roman Haefeli]

On Tue, 2007-05-08 at 12:56 -0400, Mathieu Bouchard wrote:
> On Tue, 8 May 2007, Roman Haefeli wrote:
> 
> > yeah, i am pretty sure. if i record it to a file.mov, i can swap R and 
> > B, when playing with mplayer and then it looks fine. a similar issue, 
> > but with wrong colorspace, i have in gridflow with the same usb-cam, 
> > therefor i know, how it looks, when rgb is displayed as yuv.
> 
> If you try (R,B) swapping correction, but somehow tones of orange look 
> too yellow and tones of cyan look too blue, the problem was actually a 
> (U,V) swapping problem. (I mentioned this in gem-dev archives)

though i probably don't have a deep understanding of these things, i
think you are right. 
i made some screenshots on:
http://www.romanhaefeli.net/gem/

the original.jpg is a screenshot from a capture to mjpeg/mov from usbcam
from gem, played by mplayer with no additional options. the swapped.jpg
is a screenshot from the same videofile, but played with 'mplayer -flip
-vf swapuv,scale'


> Besides, with recent versions of GridFlow, USB cams don't have to be 
> handled as YUV and the default conversion is to RGB, and it's much faster 
> than in version 0.8.4.

good news, i'll try it soon..

roman


		
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