[GEM-dev] 0.90 and pix_video under Linux

[Mirko Petrovich]

IOhannes m zmoelnig wrote:

> Mirko Petrovich wrote:
>
>>
>>
>>> probably your [color]/[colorRGB] is set to black ? (or the 
>>> alpha-channel  is 0 ??)
>>> thinking of this, it might be, that the video4linux-driver is able 
>>> to produce RGBA-images but unfortunately sets the alpha-channel of 
>>> each pixel to 0. in this case, you will have to raise it manually. 
>>
>>
>>
>> I checked this, and it's not the problem , the strange thing is that 
>> alpha works in pix_gray and even in pix_yuv (I get a distorted image, 
>> I guess this is right).
>
>
> this isn't strange as [pix_grey] and [pix_yuv] use colour-spaces that 
> do not have an alpha-channels (so it is automatically set to 1)
> i still believe that the problem is, that [pix_video] returns 
> RGBA-images with alpha=0 (you could watch this with [pix_histo]
> furthermore, you can send a [colorspace YUV( or [colorspace GREY( 
> message to [pix_video], which might be faster (depending on the 
> video-capture-device)

Yeah !! now it's working, sending |colorspace 2( to [pix_video] did the 
trick.
Just for the record, I'm using a saa7134 capture card.

Thank you very much, I was really puzzled.

-- 
Mirko Petrovich
Santiago de Chile