ZMLarch and webcams

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Note: The info below applies to the initial 1.24.1 version of ZMLarch. As of ZMLarch_svn_2872 web cam support is much improved, and most webcams should work "out of the box." Since moving to linux kernel 2.6.29 gspcav1 is no longer included or needed.

Many webcams are supported on linux by the gspca driver modules. There are two versions of gspca, vervion 1 supports only the V4L version 1 API.

gspca version 2 which is now in the main linux kernel tree supports V4L2. Until very recently V4L2 support in ZoneMinder was very incomplete. So many webcams did not work or did not work properly with ZM. By using the old gspca version 1 modules some webcams were usable that did not work with gspca2.

Support (kernel modules) for both gspca 1 and 2 are included with ZMLarch. To prevent udev from loading both modules (neither will then work) a line in /etc/rc.conf blacklists one of them. By default ZMLarch uses gspca version 1 and blacklists version 2. At this point I believe this will work "out of the box" with a wider variety of hardware. Its always nice when you can boot the CD and immediately view your camera in zoneminder. :)

The relevant line in /etc/rc.conf looks like this:

MODULES=(!gspca_main)

Note the ! which means "not". To disable gspca version 1 and allow gspca2 edit this line to look like this:

MODULES=(!gspca)

To test the newer modules from the liveCD you can change this before you plug in your webcam. If your webcam is built in (laptop) you will need to remove the offending module from the running kernel and insert the correct one. For example:

"sudo modprobe -r gspca && sudo modprobe gspca_main"

Be aware that the newer modules and V4L2 API will be fussier about settings (ie palettes) than the old versions. Hopefully the command line utility "v4l-info" will be helpful in determining proper settings for your particular hardware.

Please report your experience with the new modules and up to date ZoneMinder revisions. When is seems appropriate I will make gspca2 the default on later versions of ZMLarch