Laurent Pinchart wrote:
> Hi Raúl,
>
> sorry for the late reply, and thanks for the very detailled description of
> your problem.
>
No, that's ok. We are all quite busy, specially if you are doing some
important development like it is this driver.
>> Now I'm more certain that this is a trouble in the light regulation
>> mechanism, but I don't know how to get more information from the driver.
>> I don't know even where the light regulation happens. Is it on driver, on
>> hardware or in the userspace application by chance (doubtfully this
>> last)?
>
> The driver doesn't perform any image processing. What you call light
> regulation is mostly auto-exposure (and maybe to a lesser extent auto
> white balance). Your camera doesn't report any exposure-related control in
> its USB descriptors, so it's not clear if the camera doesn't do any
> exposure control or if it doesn't allow exposure parameters to be changed.
> I'd vote for the second option.
I can't be sure about this as well, even more when I haven't tried with
another drivers (BillyOS). But I think it would be odd that having the
possibility of running into this trouble the camera doesn't provide this
controls.
>
> Userspace applications can also implement all kind of image enhancement
> algorithms. That's up to the application, and there's no easy way to know
> what skype does due to its closed-source nature.
Well, skype is one case more. As I mentioned the problem also raised with
kopete.
>
>> My most reliable method to reproduce up to know is being on a very soft
>> light environment, for example: night with a dim indirect light(12W low
>> consumption lamp). In this situation you will see the image, but not very
>> well defined using a regular videoconferencing resolution and frame rate.
>> Now cover the camera focus completely using your hand, the image will
>> become totally black and, if the light is not clear enough it will remain
>> in that state unless you reinitialise the video streaming or use a light
>> enough light so the brightness regulates automatically to a useful value.
>
> That seems to be a bug either in the camera hardware/firmware or in the
> application. I'd try using the camera with luvcview. If you can reproduce
> the problem the hardware will be to blame. Otherwise skype will be at
> fault.
Now that I know how to reproduce the problem and provided your information
I've tried with luvcview and well, I got to reproduce it as well. So this
could be a better starting or (maybe unhopefully) ending point.
In summary turn on the video streaming where there's very little light, in
the end the camera stream will turn black.
>
> Best regards,
>
> Laurent Pinchart
Thanks a lot for your comments,
--
Raúl Sánchez Siles
----->Proud Debian user<-----
Linux registered user #416098
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