ZoneMinder Forums

I'm having a problem with ZoneMinder corrupting the images captured from my webcam.

I'm running ZoneMinder 1.18.1 on Mandrake 10 (using 2.6.3-4mdk kernel). My webcam is a Logitech Quickcam Express. The webcam works beautifully with XawTV, Camorama, and other utilities.

Compare this image:
http://home.comcast.net/~amerrifi/043-capture.jpg
with this image (taken immediately after):
http://home.comcast.net/~amerrifi/044-capture.jpg

The resolution for these two images is 352x288. Note the second image has a previous image's timestamp on the bottom. It seems like there is some memory corruption going on. Is this a shared memory issue?

One more set of images,
Compare these two images:
http://home.comcast.net/~amerrifi/2879-capture.jpg
http://home.comcast.net/~amerrifi/2880-capture.jpg

The resolution here was set to 340x280. Notice that the wrong timestamp is now in a new location.

The corruption happens every other image. Occasionally the corruption will last for two frames, and then revert to every other frame after that.

Is this something I can fix in the configuration? There are no error messages being traced out to /var/log/messages.

Thank you in advance for any help.

Adam

Hi Adam,

Is the timestamp the ZM one, or one your camera has added?

One thing to try, especially if you have a fast frame rate on that camera, is slowing down the frame rate with the max FPS setting. Sometimes that corrects this kind of error, and you can then increase it until it works. Utilities like xawtv usualy just map the video onto the screen buffer and so use a different method than ZM since they never need to actually inspect the image. Have you tried doing image grabs with other applications as they would use the ZM method.

Phil,

Thanks for your reply.

The timestamp is the ZM one.

I reduced the max FPS to 1 and still had the exact same problem (once every frame). I just tried grabbing images from XawTV and Camorama and both had no issues (with XawTV I recorded about 10 frames/s).

Any ideas?
Adam