[mythtv-users] [OT] webcam stuck on 160x120

[Mainiac]

> Putting this here because:
>
> 1. the box concerned is a frontend and also running mythzoneminder;
>
> 2. Although not strictly mythtv related, there are a lot of people
> round here who know a lot about v4l (which guessing is the source of
> the problem).
>
> I am setting up zoneminder on ubuntu 10.04. I have a Philips SPC530NC
> webcam which seems to be capable of 640x480, according to advertising
> and other info on the web. See by way of example:
> http://www.testfreaks.co.uk/webcameras/philips-spc530nc-00/
>
> However the camera doesn't seem capable of doing more than a miserable
> 160x120 when plugged into my system. All the tools (v4l-info, lucview,
> lsusb -v etc) report the width as 160 and the height as 120. However
> output from similar commands, eg here:
>
> http://lists.berlios.de/pipermail/linux-uvc-devel/2008-October/004146.html
>
> show that people have got the correct resolutions from this device.
>
> Any idea where to go from here?


I had similar issue with a different web cam, what I found was that I
needed to increase shared memory in the kernel for the camera.

The following will change your running kernel's shared memory:

# echo 134217728 >/proc/sys/kernel/shmall && echo 134217728
>/proc/sys/kernel/shmmax

That will not stay when you reboot, you will need to edit
/etc/sysctl.conf adding:
kernel.shmmax = 134217728
to make the change permanent.