Monitors break above a certain resolution

[Jimmy]

Hi guys,

Firstly thanks for previous advice to change owner of the logs to apache user and group. Worked a treat got zone minder running.

However, further problems...

Using the latest version of zoneminder if I up the resolution of my monitors over 352x288 the "source" field turns red, and when I click the "name" field to open the monitor's window, I am presented with a broken image (red x).

Log files aren't showing anything, and the only way to fix this is to reset the resolution of the monitor to 352x288 or lower and actually restart the computer -- the image remains broken until the machine is restarted.

using the "webcam" program on the same system (Slackware 9.1) I am able to achieve a max resolution of 512(H)x582(V) with my BT878 based tv card and AVC 527 CCTV camera, so I know it's not a hardware problem.

Any advice much appreciated.

Many thanks,

Jim

[zoneminder]

This is likely to be because of one of two related reasons.

1) You are increasing the monitor size while ZM is running. In this case if other process are attached to the shared memory segment it cannot be freed and enlarged. Try shutting down ZM entirely, changing the size and restarting.

2) You don't have enough shared memory allocated on your system. See the FAQ for instruction on how to address this. As a workaround you could reduce the ring buffer size by the inverse factor of the screen increase to keep the allocation roughly the same. So if initial ring buffer size is 100, initial screen width is 320 and initial screen size is 240 then changing to 640x480 results in an increase in screen size of 4 so reduce the ring buffer by the same amount, so make it 25. This may have other consequences so if you have the RAM then increasing the amount that can be used by shared memory is preferable.

Phil,

[Jimmy]

2) You don't have enough shared memory allocated on your system. See the FAQ for instruction on how to address this. As a workaround you could reduce the ring buffer size by the inverse factor of the screen increase to keep the allocation roughly the same. So if initial ring buffer size is 100, initial screen width is 320 and initial screen size is 240 then changing to 640x480 results in an increase in screen size of 4 so reduce the ring buffer by the same amount, so make it 25. This may have other consequences so if you have the RAM then increasing the amount that can be used by shared memory is preferable.

Phil,

Hiya not sure I understand this part, if the initial size is 320x240 and the new size is 640x480 (2x) would I not then have to half the initial ring buffer size of 100 to 50 (inversed factor).

Thanks

Jim

[edit]

oic it's based on the area not the figures.

[/edit]

[davide]

no:
640x480=(2x320)x(2x240)=(2x2)x(320x240)=4x320x240

so you have to divide by 4, not by 2.

regards,
davide.

[Jimmy]

double post

[Jimmy]

well it did actually work but it's so temperamental...

at the full resolution (stated above) the image comes up blocky and there is some kind of line through it, when I get home tonight I'll post a copy and someone might be able to advise?

if I change the function from say monitor to record, the image breaks, in fact changing most any setting related to that monitor causes the image to break.

I'm not really sure what else I can do now, I need the resolution to be high so that the recordings could be played back in full screen high definition.

[zoneminder]

If you're using multi-part jpeg format to view, ie Mozilla native or IE with Cambozola then try using nph-zms rather than straight zms in the ZMS_PATH option. That assumes that if you just look at a single image (or a stream in MPEG mode) it looks ok but only breaks when streaming jpegs. The other thing to be wary of with large images is that at high frame rates the data bandwidth required can do nasty things to the PCI bus. It shouldn't matter with just one or two cameras but more than that and you could be in trouble.

Phil