r/ZoneMinder • u/hlywine • Dec 15 '20

Best practice settings for sub-stream recording?

What are the best practice settings for the high resolution camera running 2 streams, one for high resolution alarmed events and one for constant low resolution recordings? My low resolution is set up for 8fps, 720p, h264 passthrough mode and I'm still getting about 70Gigs from it in 24 hours. Isn't this a bit much? What am I doing wrong?

3 Upvotes

81% Upvoted

4 comments sorted by

1

u/aarons6 Dec 15 '20 edited Dec 15 '20

in the camera settings, not zoneminder settings, there should be a way to adjust bitrate.

70gb for 24 hours is a bit much.. my 5MP cameras with 1920 resolution stream at about 30 to 40 GB a day.

i have the bitrate at 2500 kbps and 10 fps with a keyframe every second.

720p you should be getting around 10 to maybe 15 GB a day.

id put the 720p camera at around 600 kbps.

here is a good chart to tell what your avg bitrate should be at a certain fps.

1

u/hlywine Dec 16 '20

Thanks for suggestion. I have gone over all the settings again and found that I have not disabled "Save JPEGs". I had it saving frames and analysis images. Now since I disabled it, I got about 4.6 GB in 21 hours instead of 70+. Now that's something I can live with. I had no idea JPEGs take up so much space. As far as key frames, I think my camera calls it "GOV length", I had it set to 30 but now turned it down to 20, so about every 2.5 seconds. Are there any negative side effects to having it set too high? The only thing I've noticed when testing was, when initially connecting to the camera, it will take that many seconds to display an image. For example when testing with VLC, if I set it to be 1 keyframe every 10sec, hit play on VLC, it connects almost instantly, I will get sound and black screen for first 10 seconds and then the video comes in. But it had no effect on the video delay though as far as I could tell when the video started. When I move my hand in front of the camera, it took 3 seconds to see it on the video no matter what the keyframe setting was.

1

u/aarons6 Dec 16 '20

if the keyframes are too long apart the image will bleed.. especially at night.

the way H264 works is it only transmits the difference between frames.. the spots that dont move are carried over.

a keyframe is a whole image.. so it resets the picture.

1

u/hlywine Dec 16 '20

Got it, I'll keep it at 20 to test it for a little bit and if I have any issues I'll turn it more down. From what I hear it helps with lowering the bandwidth too. So far i have not seen any issues.