Re: libv4l release: 0.5.97: the whitebalance release!

[Hans de Goede <hdegoede@redhat.com>]

On 04/18/2009 12:13 AM, Adam Baker wrote:
> On Friday 17 Apr 2009, Hans de Goede wrote:
>>> I've tested it by plugging in the sq905 camera, verifying the
>>> whitebablance control is present and working, unplugging the sq905 and
>>> plugging in the pac207 and using up arrow to restart v4l2ucp and svv so I
>>> think I've eliminated most finger trouble possibilities. The pac207 is id
>>> 093a:2460 so not the problem id. I'll have to investigate more thoroughly
>>> later.
>> Does the pac207 perhaps have a / in its "card" string (see v4l-info output)
>> ? if so try out this patch:
>> http://linuxtv.org/hg/~hgoede/libv4l/rev/1e08d865690a
>>
>
> No, no / in the device name.
>
> I've tried enabling the logging option in libv4l while running v4l2-ctl -l to
> list the controls present on each camera but I can't see any significant
> looking differences in the log other than the the fact the sq905 seems to get
> many more unsuccessful VIDIOC_QUERYCTRL requests. Unless you have a better
> idea my next step would be to extend the logging to include the parameters on
> the VIDIOC_QUERYCTRL ioctls, however my gut feel is that it is related the
> camera having controls that have CIDs both lower and higher than the ones
> libv4l adds and libv4l doesn't do anything with the driver returned values if
> V4L2_CTRL_FLAG_NEXT_CTRL is set.
>

Ah, you are using v4l2-ctl, not v4l2ucp, and that uses V4L2_CTRL_FLAG_NEXT_CTRL
control enumeration. My code doesn't handle V4L2_CTRL_FLAG_NEXT_CTRL (which is
a bug). I'm not sure when I'll have time to fix this. Patches welcome, or in
the mean time use v4l2ucp to play with the controls.

Regards,

Hans