1.25 => 1.26.5: incredible false positives for motion- HELP!

[TheKorn]

So I recently upgraded zoneminder from 1.25 to 1.26.5. Was running great under 1.25, had things dialed in to the point where I'd get a false positive maybe once a month.

Under 1.26.5 though, all hell has broken loose. With the same zone settings (not to mention cameras... ) as I was using under 1.25, I'm getting false positives all the time! And for the life of me I can't figure out what's causing it!

In an effort to see like a computer, I took the previous frame and subtracted the frame that zoneminder alarmed on. (photoshop, two layers, difference blending.) Using that, anything that's the same is black, anything that's different is white. The analysis confirms what my eyes are seeing, that there's almost no difference between the non-alarmed and the alarmed images! Worse, what trivial differences there are between the two images do not in any way correspond with the area that zoneminder highlighted in its analyse image!

What's going on!?? Is there some snafu with upgrading from 1.25 to 1.26.5 that completely breaks motion detection?

They say a picture is worth a thousand words, so here are three...

[TheKorn]

three more, for the complete picture. Note that the blobs that zoneminder drew correspond to almost nothing in the changes picture!

Any ideas of things to check? It seems as though motion detection has gone crazy haywire here. But since we're on 1.26.5 and it hasn't come up before, seems as though this is a migration issue rather than a core "motion detection is broken" kind of issue.

Thanks in advance!

[bb99]

Try changing the value for: "monitor::buffer::Alarm Frame Count" to a value of 4. I've never had to go that high (usually 2 or 3 stops this) but your example shows 3 consecutive false alarms.

[TheKorn]

Try changing the value for: "monitor::buffer::Alarm Frame Count" to a value of 4. I've never had to go that high (usually 2 or 3 stops this) but your example shows 3 consecutive false alarms.

Root cause turned out to be the upgrade putting in no value at all for "alarm reference image blend %-age" nor for "reference image blend %age" for each monitor. Once I put in values for that for all monitors, back to well defined (for my intents, identical to v1.25) behavior.

Have to wonder out loud why these have no default values, since they aren't maintained from an existing zoneminder install? (And why does the color space default to 8 bits instead of 24, which would be the more common default?)

Small bumps in the road in the grand scheme of things, but seems like all three of these could be better handled on a database conversion. Or at least documented. (To be fair, the color space thing was documented in the forum. The other one I found randomly surfing threads in the forum that had nothing to do with this!)