4.6.4 - October 21, 2017

beepsilver

Getting comfortable
Joined
Mar 9, 2014
Messages
863
Reaction score
982
Location
Nebraska
New Limit decoding definitely causes missed motion events. ver 4.6.4.6
I noticed this yesterday--If you turn that option off, does your motion detection return to normal?
 

Spooling

Getting the hang of it
Joined
Sep 26, 2015
Messages
158
Reaction score
48
I noticed my camera wasn't triggering as it normally would with this option enabled as well. I use the zone cross triggering as well. I was going to increase my camera Iframe interval to help, but it's already at the max setting of 20. My Camera's video feed is 20fps as well. I disabled the option again to fix the issue.
 

bp2008

Staff member
Joined
Mar 10, 2014
Messages
12,680
Reaction score
14,041
Location
USA
Yep, you are basically limiting the motion detector to 1 FPS if you only have one 1 iframe per second and have "limit decoding" enabled. I think the motion detection algorithms are probably not well-tuned for extremely low frame rates where objects do not move smoothly at all.

I figure the best compromise would be if Blue Iris was able to utilize sub-streams for motion detection and live view, always receiving the main stream too but not decoding it unless the camera was maximized. This could deliver most of the CPU savings with fewer downsides (except added complexity).
 

Tuckerdude

Getting the hang of it
Joined
Apr 28, 2014
Messages
193
Reaction score
79
Location
Seattle Area
Hey guys...one thing to note is:

If you are running a bunch of cameras (say more than 10) and you are hitting a high CPU load, it seems that "Cherry Picking" which of those cameras you enable the "Limit Decoding" option on can really help the overall situation. Case in point, my BI install at our house in Arizona. At first I only planned to have about 6 cameras there just so I could keep an eye on things when we are not there (can be for months at a time btw). So I went to Costco and bought a medium range PC to setup there. It's a mid-range i7 Dell machine with 8GB of ram. As I started adding just a couple more cameras, the CPU usage started to quickly creep into the 90% range and stuck there. So I enabled the "limit" function on about half of the cameras (those that are not super critical) and kept ones like the front door, courtyard, side gate untouched. I was able to bring the CPU load all the way back down to roughly 40% and still have the main cameras running at full clip and with good results in capturing activity around the house.

Anyway, just thought I would share my experience and think that this feature when used "As Needed" can really save on wear and tear on your machines.

Happy Halloween Folks!
 

hdcam01

n3wb
Joined
Jun 11, 2017
Messages
16
Reaction score
10
4.6.4 - October 21, 2017

  • A new option on the Video tab in camera properties "Limit decoding unless required" can be used to lower CPU demand by only decoding video key frames instead of all frames. Generally an H.264, H.265 or MPEG4 stream will encode a key frame once each second, and this is usually enough for the motion detector to operate. When the software determines that ALL frames are required for webcasting or recording without direct-to-disc mode, all frames will be decoded. In addition, all frames will be decoded if the camera is full screen.

  • A new option on the Schedule tab in camera properties "Camera is only active when viewed remotely or full screen" can be used (in conjunction with un-checking the box Continue to display and stream video) to close the camera stream completely when not required for webcasting.

  • Following an ONVIF find/inspect operation, the "events subscription" was always enabled if the camera reported support for this. However this needlessly used network bandwidth if it was not required (in conjunction with camera triggering for example). The default is now OFF.

  • The camera border will be yellow when the motion detection is paused, such as after a PTZ command or PTZ preset position change.
^^^^^^^^^^ "Limit decoding unless required" ^^^^^^^^^^^^

For this feature and this feature alone, I am signing up for the annual plan. All these little tweaks make a huge and positive difference


Specific to enabling the feature above, that right there dropped my CPU from 30% to 5%

Config:
5 x Amcrest 4K Cameras (2304 x 1296) 3MP @ 20fps
HW Decode (+BVR) no VPP
Intel i7 3770K OC to 4.5 GHz
NV GTX 660ti SC OC

Thank you Ken!!!
 
Top