Framerate - xawtv VS zm

heinricza · Post by **heinricza** » Tue Mar 22, 2005 4:53 am

I am busy testing zoneminder and have the following question:

I am using a 4-way BTB878 card with a 4 chips, one for each channel supporting 30fps for each channel. When I run zm in monitor mode, the fps decreases for every monitor I add.

However, if a run four consecutive xawtv processes, one for each device, I see a perfect 30fps for each video device.

Is this a web server problem, or am I missing the boat completely?

Kind Regards
Heinrich Venter

Post by **cordel** » Tue Mar 22, 2005 5:02 am

The Frame rate should not decrease... Unless the system you are running it on has a limited resource that is needed sorta thing(everything has a limit). If you are running colour at say 640x480 that could ask allot from a PIII 500 (just as an example, There is an equation for this but I don't remember it). So the question would be :
What Distro?
What Processor?
How much memory?
What capture card?
etc.. etc..

heinricza · Post by **heinricza** » Tue Mar 22, 2005 5:30 am

At the moment I'm testing on the following spec'd system:

Redhat 8
P4 2.8Ghz
512MB RAM
40GB IDE HDD

The montage pictures runs at 320x280.

heinricza · Post by **heinricza** » Tue Mar 22, 2005 5:32 am

I'm running Apache 2.0.40 and have not patched it yet according to the post in the FAQ. Maybe that could be the problem?

Post by **cordel** » Tue Mar 22, 2005 5:39 am

That might be a good bet. As you should not be have a problem with just four cameras on that system.

Post by **zoneminder** » Tue Mar 22, 2005 9:58 am

Heinrich,

Are you running the four xawtvs at the same time? I assume you are though I don't think it should make a difference. Xawtv as I understand it just allows the video stream to map itself to your screen memory and there is no intervention required. This allows viewing but not capture. If you want to capture you have to run frame grabs (in the same way you can grab individual frames from xawtv). It is this which ZM uses (and anything else that wants to capture), and this takes more time as it has to switch between inputs (if you have a card with a single frame grabber chip on it). If you can capture video with xawtv and try this on all your cameras you will see the frame rates decrease in the same way.

Phil

heinricza · Post by **heinricza** » Tue Mar 22, 2005 10:09 am

Tx Phil

That makes a lot of sense. I thought it might be something in that line. What is a decent framerate that I can expect then from a system running 4 cameras on a board with 4 chips?

In other words, what are the benchmarks out there for a similar setup?