ZoneMinder Forums

I have lines in recorded events that are usually around the lines of motion. I don't know if it a hardware problem, although it has happened on two different 16 port cards or if it is something in the software that I can tweak. Any ideas would be appreciated. It happens about every 6 - 8 frames during a morecord, the rest of the frames look great. Thanks







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Allan

How do you have your cards configured?
How many cams, at what resolution/palette, and what are your pre buffers set to (see the Wiki FAQ or the README for calculating shared memory size as this is really what I'm after is the total needed for your system)?
What do you have your shmmax set to?

I have the 16 port, 120 fps card from bluecherry. I have it setting the bttv option card type to 77,77,77,77. This allows me to use all 16 channels, not all channels would work until I did this.

I am running the cameras at 320x240 with a RGB24 palette. I am using the defaults on my buffers as
Image Buffer Size=40
Pre Event Image Buffer=10
Post Event Image Buffer=10

My shmmax is set to 134217728 and I have it set in /etc/sysctl.conf so it sets that when it boots. Any ideas and thanks for the help.

Allan

via chipset?

So you need 9.216 MB per cam plus upto 10% overhead.
Camera total 147.456 MB
10% is 14.75 MB

Total Shared memory needed is 162.202MB
You have set 134217728

You about 28 Meg's short.

Is shared memory pulled from the ram, swap, or hard drive? Thanks for the help that makes sense. I just estimated and thought I had enough.

Allan

cordel wrote:So you need 9.216 MB per cam plus upto 10% overhead.
Camera total 147.456 MB
10% is 14.75 MB

Total Shared memory needed is 162.202MB

How did you calculate this?

It's described in the README and the Wiki FAQ.

robi wrote:How did you calculate this?

frames are kept uncompressed in memory

320 pixels by
240 pixels
= 76800 pixels

76800 pixels by
3 clolors by
8 bits per color (so called 24bit colors)
= 1843200 bits per frame
1843200 bits per frame by
40 frames (the ring buffer size)
= 73728000 bits per camera
= 9216000 bytes per camera
= 9.216 MB per camera
+ 10% that is used by trigger data etc.

Oops, a little error in your calculation, as 1kB = 1024 bytes, not 1000! Same as MB vs kB.

In my case:
384x288 resolution, that makes: 110 592 pixels
in 24 bit color that's 2 654 208 bits per frame
by 80 frames ring buffer = 212 336 640 bits per camera
by 4 cameras = 849 346 560 bits.
Plus 10% overhead = 934 281 216 bits
That's 116 785 152 bytes, and
= 114 048 kB, respectively 111.38 MB.

If my shared memory is set to 134 217 728, which is exactly 128MB,
that means that I shouldn't have any problem, right?

How big can I set the shared memory on the system? I have 1 Gig of RAM.

robi that should be fine unless your having a problem with your system.

cordel wrote:robi that should be fine unless your having a problem with your system.

Thanks. I changed it to 256Megs, for "just in case".

I upped the shared memory to 256000000 and I have 1.5 gigs of RAM in the system. I am still getting the lines pretty bad in three cameras. The rest look great. Here is a picture from a few minutes ago during a recorded event.



Link just in case
http://www.flickr.com/photos/81546799@N00/484172437/

I am not sure about the chipset on the card. It is a
PV-155 - 16 port video capture card (120FPS)
from BlueCherry
http://store.bluecherry.net/16_port_vid ... pv-155.htm

Any other ideas?

have you tried to run memtest? just a wild guess.

Are all these cameras on the same device (ie. all on /dev/video1)?
I assume you restarted the zm service after making the shared memory changes?