Author Topic: Pre-Trigger Frame Buffer Size?  (Read 1743 times)

Offline Q

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Pre-Trigger Frame Buffer Size?
« on: April 14, 2013, 04:45:00 pm »
What is the setting you use (if any) for the "Pre-trigger frame buffer size?" I'm uncertain as to (1) if I need it or (2) what to set it at.
 
Here's what the BI Help says about it...
 
Quote
Pre-trigger frame buffer size. Blue Iris maintains a buffer of images as they are received from the camera--when motion is detected, you may choose to record up to 50 images from this buffer so that you can see what occurred just prior to the event which actually triggered the motion sensor.  Please note that the use of this feature consumes considerable memory and CPU resources--it should only be used if you have both to spare.

What is your opinion about the "Pre-trigger frame buffer size?"
Q

Offline Q

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Re: Pre-Trigger Frame Buffer Size?
« Reply #1 on: April 14, 2013, 05:36:08 pm »
John, thanks...
 
I use different Frames Per Second (fps) & Pre Trigger Frames (PTF) on my cameras.

I made up this little chart to give me an idea of what extra time I get.


            50 PTF                       30 PTF                        20 PTF
@   5 fps = 10   sec      @   5 fps = 6    sec      @   5 fps =  4    sec
@ 10 fps =  5    sec      @ 10 fps = 3    sec      @ 10 fps =  2    sec
@ 15 fps =  3.3 sec      @ 15 fps = 2    sec      @ 15 fps =  1.3 sec
@ 20 fps =  2.5 sec      @ 20 fps = 1.5 sec      @ 20 fps =  1    sec
@ 25 fps =  2    sec      @ 25 fps = 1.2 sec      @ 25 fps =  0.8 sec
@ 30 fps =  1.6 sec      @ 30 fps = 1    sec      @ 30 fps =  0.6 sec


PTF/fps=Extra Time Recorded (gives you times for other combinations).
Q

Offline Q

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Re: Pre-Trigger Frame Buffer Size?
« Reply #2 on: April 14, 2013, 05:37:21 pm »
John, can you give us an idea of the performance hit that "Pre-Trigger Frame Buffer Size" exacts on your CPU(s)?
Q

 

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