Hi Laurent, thanks for the answer!
On Sunday 23 March 2008 21:26:07 Laurent Pinchart wrote: > > After noticing that the private controls are gone and updating some > > keys everything but one thing works again: I can't set the auto exposure > > any more. When I query V4L2_CID_EXPOSURE_AUTO it is set to 3. > > V4L2_EXPOSURE_AUTO and V4L2_EXPOSURE_MANUAL at the same time? > > 3 is actually supposed to mean V4L2_EXPOSURE_APERTURE_PRIORITY. The control > values were not properly defined in uvc_compat.h, I've just committed a fix > to SVN. Ah, ok. great. Problem seems to be gone :) > > Now my other problem: When reading r187 I hoped to be able to manually > > set the white balance, but it doesn't seem to be possible. > > Setting V4L2_CID_AUTO_WHITE_BALANCE to 0 doesn't seem to have an effect. > > The control seems to be neither V4L2_CTRL_TYPE_BOOLEAN nor > > V4L2_CTRL_TYPE_INTEGER, so what else it is? > > The control is boolean, and is supposed to work. Do you get an error when > you try to modify it ? Is anything printed to the kernel log ? Do you get > the previously written value when you read the control back ? Hehe, indeed, it is boolean. I had a typo in my code. > > > When trying to get V4L2_CID_RED_BALANCE or V4L2_CID_BLUE_BALANCE I get > > the error code 22, Invalid argument. In the syslog I find > > > > | uvcvideo: Control 0x0098090e not found. > > | uvcvideo: Control 0x0098090f not found. > > > > Is this expected to work, or can't this work? It is quite important for > > me, to get the manual white balance running. > > The SPC1300NC has a white balance temperature control, you should use > V4L2_CID_WHITE_BALANCE_TEMPERATURE instead of V4L2_CID_RED_BALANCE and > V4L2_CID_BLUE_BALANCE. Hm, ok. Setting V4L2_CID_WHITE_BALANCE_TEMPERATURE seems to work, but the image has a red cast. The closer the value is to 2800 (6500 seems to be the default), the better the image looks, but even at 2800 Kelvin the red cast is not gone. In my use case a red cast is the worst case (blue would be much better)... I think I once tried the camera with Windows and I could adjust the red and blue temperature -- any idea how this is possible? Maybe Philips implemented this part somewhere in their driver/user space tool? What is even worse: The white balance doesn't seem to be fixed if V4L2_CID_AUTO_WHITE_BALANCE is set. The camera still changes the colour temperature, when the lighting conditions change. Weird, isn't it? If you want I can make a little video to show the effect. > > Any help is welcome :) > > Hope this helped :-) Definitely :-) Greetings, Armin _______________________________________________ Linux-uvc-devel mailing list [email protected] https://lists.berlios.de/mailman/listinfo/linux-uvc-devel
