[PD] [pix_video] with v4l

Mathieu Bouchard matju at artengine.ca
Tue Sep 8 05:26:44 CEST 2009

On Mon, 7 Sep 2009, IOhannes m zmoelnig wrote:
> Miha Tomi wrote:
>> On Linux using Gem 0.92 from SVN I am using [pix_video] with Logitech
>> QuickCam 4000 and v4l driver but the red and blue colours are swapped.
>> Is there a way to instruct [pix_video] to use different colorspace (BGR
>> instead of RGB)? If not what is the cheapest way to convert from one
>> colorspace to the other.
> a simple _hack_ is to use YUV-colorspace with [pix_video] and then (if you 
> really need it) [pix_rgba] to convert to RGBA.

Do you mean that the BGR thing is a bug in Gem or what? Because if it 
isn't, then YUV might as well be YVU, in which case you'd still use 
[pix_colormatrix], but possibly with different constants... what is 
[pix_colormatrix] supposed to do on a YUV image ? are its coefficients 
still RGB-wise in that case?

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| Mathieu Bouchard, Montréal, Québec. téléphone: +1.514.383.3801

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