False positives

veert

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I've been using TinyCam for a few months now, and I think, it's a very well thought-out app.

One area that's giving me trouble, though, is false positives. I'll be as specific as I can:

In-app motion detection
Video source: Blue Iris / v4 / H264
Sensivity: 35

Now, it would make sense to reduce sensitivity, right? I did lower it to 25.... only to start getting more false alarms. How do I know, those are false? By cross-checking them with Blue Iris.

No continuous recording.
No recording within TinyCam, either.

So, technically speaking, I can't be 100% certain, nothing happens.

One thing I know, though,is that Blue Iris is unlikely to miss potential events in this area, since there's more than one cam watching it from different angles. Plus, for some reason, those false alarms mostly happen at night, when the area is illuminated with LED lamps. Last night, I experienced two of those within 15 minutes while holding the phone in my hand and looking at the live feed in near real time.

The scene is indoors, so no moving trees, etc.

Questions for the dev:
* is a 10% drop in sensitivity not enough?
* how can a drop in sensitivity increase the number of alarms?
* could it be something to do with LED light spectrum, power fluctuations etc.?
 

alexvas

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Can you record a false positive mp4 file and send it to me for troubleshooting?

* In most cases it is enough.
* Increase of sensitivity should increase number of motion alarms.
* That could be with power frequency fluctuations, LED light spectrum, etc.
 

veert

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PM'd you.
Everyone else - guess, I'll post an update once we have meaningful results.
 

veert

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FWIW, the alarms are caused by weird artifacts, such as:
* image suddenly turning blue, or
* image turning blue with a green outline of the scene being visible
* image turning black with a whitish outline of the scene visible
....etc.
Naturally, such frames get registered as motion.
What causes those, I don't know. It could be the fact that I use a custom ROM, or anything else. I don't feel like messing around w/ codecs, even though that might be the right thing to do. Tried both primary and secondary channels, if that makes any sense for a Blue Iris installation.
 

veert

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Did some more research. Guess, another update might be in order for those interested in the false positives issue.

As a matter of fact, my codecs seem to only be a problem as far as my clip recording ability is concerned. I still get snapshots of events on Android's lock screen. Also, I put the camera in question on constant recording in Blue Iris for cross-checking with TinyCam.

From what I can see, there might have been some connection problems causing the artifacts described in my previous post. At the same time, further positives were caused by insects and the like. Small insects far away from the camera, I should add.

Now, neither would be a problem if TinyCam was able to ignore small objects or frame-wide changes. But it can't. I don't think, playing around with sensitivity settings is the right way to fix this - too much uncertainty.

Given that the app is quite solid in other respects, the developer might want to take note of this
 

veert

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Yes. And no.
In TinyCam, you can't just reduce the size of that area - you are forced to also position the smaller area within the frame. Doesn't solve much in such cases as mine.
 
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