ZoneMinder Forums

Hi.

I would like to ask if it's somehow possible to tell ZM to keep some time in a buffer and save it when it's asked for.

I made ESP32 based PIR sensors to trigger an alarm/recording. But it takes a while until the interrupt wakes the device, connects to WiFi, and sends a request. An idea is to use API to tell not only to start recording "now" but also to add e.g. 5s of buffered video "before now".

Is it somehow possible?

Buffers is the key to what you want to do. All depends upon how much memory you want the buffers to use up.
The setting is Pre Event Image Count in Buffers. I have mine set for 30 which at a camera frame rate of 10 FPS gives me 3 seconds of recording before an event is shown. I also use 10 Post Event Image Count.
So the math is simple here and it all depends on how long your trigger takes to work.
There is also an option called OPT_TRIGERS that may work for you.