Genuis usb web-cam resolution 320x240, 640x480 not work

[aivs]

Hello, i have a cheap web-cameras Genius, and noname, Noname works good with resolution 640x480, Genius works only with 320x240, in 640x480 i see black screen with сolor strips on top. And zoneminder show that speed of shots = 3,53 fps. How to force to work Genius web-cam ??

[bb99]

Are you sure Genuis cam supports 640*480? I'm seeing allot using 704*480. The camera output and the ZM monitor configuration must match exactly (both resolution and palette). Another possibility is your shmmax value is too low for this cam. To eliminate that, change the shmmax value in /etc/sysctl.conf to a value of 268435456.