FPS Report Interval oddity

[jwarfin]

Running 1.30.4 on Ubuntu 18.04. Installed via one of the "easy way" scripts covered on the wiki.

I've been running 7 IP cams for a while now, no real issues. But I did notice something odd that I'll share...

I've setup each of my cams the same, which includes the Misc monitor setting "FPS Report Interval" set to 1000. This setting is supposed to control how often the "Capturing at" and "Analyzing at" messages appear in syslog. Today I realized these messages were actually being logged much more frequently than 1000 seconds (~16min), but more like every 2 or 3 minutes. Kind of odd, but no worries: I've been considering turning off those log messages anyway.

So, I went ahead and set "FPS Report Interval" to "0" (zero) for each cam. This setting is supposed to disable the FPS logging, and it did. But here's the odd part: after doing this, zmc CPU load dropped a bit for each cam. On average, about 2-3%. This doesn't sound like a lot, but since cam I/O factors so much into the overall system load, I do see system load averaging about 0.08 less than when "FPS Report Interval" was set to 1000.

If I get some time I'll try and take a look at the zmc source to see what could be causing so much overhead in the zmc code that handles the FPS Report Interval. But, ultimately, this is a non-issue for me because I've disabled logging FPS reports anyway.

[jwarfin]

Update to my post:

I just figured out that the FPS Report Interval is actually the number of frames between logging the reports. My cams are set to capture at 6 fps, so when I had FPS Report Interval set to 1000 the reports would be logged every 1000/6 seconds (166.6 seconds or about 2.8 minutes). So, the setting was logging at the correct interval.

But it is still odd that turning the logging off reduces load enough to be noticeable.