CMYG support in V4L2

CMYG support in V4L2

[Ondrej Zary]

Hello,
I'm working on an old driver called "qcamvc" for Connectix QuickCam VC webcams 
(parallel port and USB models), found here:
http://sourceforge.net/projects/usb-quickcam-vc/

Luckily, it was modified last year to compile with 3.x kernels.

After trivial modification (mfr and model), it works with parallel-port 
QuickCam Pro (sort of - only at 320x240 and with vertical lines on the left 
and blank part at the top). I don't have QuickCam VC (yet).

After removing a lot of code (it's now around 1200 [main] + 660 [parallel] + 
320 [usb] lines), one problem still remains: in-kernel colour conversion with 
software contrast, hue, saturation and gamma.

According to comments in the code, the camera sensor seems to have a CMYG 
filter, like no other linux-supported camera. So the proper way to support 
these cameras is to introduce a new pixel format, move the conversion to 
libv4lconvert and remove all controls not provided by hardware?

-- 
Ondrej Zary

Re: CMYG support in V4L2

[Hans Verkuil]

On 12/29/2014 02:33 PM, Ondrej Zary wrote:
> Hello,
> I'm working on an old driver called "qcamvc" for Connectix QuickCam VC webcams 
> (parallel port and USB models), found here:
> http://sourceforge.net/projects/usb-quickcam-vc/
> 
> Luckily, it was modified last year to compile with 3.x kernels.
> 
> After trivial modification (mfr and model), it works with parallel-port 
> QuickCam Pro (sort of - only at 320x240 and with vertical lines on the left 
> and blank part at the top). I don't have QuickCam VC (yet).
> 
> After removing a lot of code (it's now around 1200 [main] + 660 [parallel] + 
> 320 [usb] lines), one problem still remains: in-kernel colour conversion with 
> software contrast, hue, saturation and gamma.
> 
> According to comments in the code, the camera sensor seems to have a CMYG 
> filter, like no other linux-supported camera. So the proper way to support 
> these cameras is to introduce a new pixel format, move the conversion to 
> libv4lconvert and remove all controls not provided by hardware?
> 

Correct.

Regards,

	Hans