Please Read: Strange Bitrate Discovery when Testing Latest 8MP G2 AcuSense Cameras

[Dan]

We have not had much hands-on experience with the latest 8MP G2 AcuSense cameras, but just today we have been testing a camera that was returned to us by a customer and when analysing the cameras video settings and stream output we noticed big bitrate spikes from both a 2386G2 and an older 2385FWD with very similar settings.

Our older 2385FWD was using around 6,000-8,000Kbps with no activity in the scene and this jumped to around 13,000-15,000Kbps with medium activity in the scene (one person walking around the scene). With the 2386G2 the no activity bitrate was 5,000-8,000Kbps and with medium activity it jumped massively to between 13,000-20,000Kbps

Both cameras were the same settings (8MP/15fps/variable bitrate/highest quality/H.265) and from some tweaking of settings, we found the setting that appears to have the biggest effect on bitrate is the video quality. When we dropped this from Highest to Higher the idle bit rate of the 2385FWD dropped to around 2,000Kbps and on the 2386G2 it also dropped to around 2,000.

Obviously, using H.265+ will reduce the bitrate when using Highest video quality but for those using certain Smart Events and/or recording via a 3rd-party software they won’t have the option to use H.265+ and so for those users we would definitely recommend using H.265 & Higher video quality to reduce the spiking bitrate without a massive loss in video quality. (from our testing the quality drop is only slightly noticeable on faces/objects that are very close to the camera - 1-2m away - but this drop is not so much that you could not still identify important details)

This spiking bitrate may explain some of the cases that customers and forum users have reported to us where one or multiple cameras are not showing up on the NVR. If you take a 7608NI-I2 NVR as an example that has a max. incoming bandwidth of 80Mbps and so 4 x 2386G2 cameras set to the highest quality on H.265 are each going to be using around 20Mbps (20,000Kbps) to capture medium level activity and that is already all the bandwidth capacity of an 8-channel NVR exhausted for only 4 cameras.

 

[JB1970]

Out of interest @Dan what did you have the maximum bit rate set to? The reason I ask is from previous testing I've found that whatever you set the maximum bitrate to while using VBR - the camera will use that value and burst above it. I've just had a quick look at my 2386's - these are the ones I reported were dropping frames previously (quite badly). They are also set at 8mp but 20fps, VBR, highest quality and max bitrate set to 10240kbps.

When viewing the info panel on the monitor with no discernible motion in the image (no people in view, zero wind here today so no movement of trees or even grass), it's showing anywhere between 3000 and 17000kbps as it updates each second, even though the cap is 10240kbps. Switching down to higher and restarting the stream, those values don't alter. Switching down again to medium and the result is the same except I start to see the frame rate fluctuating and going up to 24fps (20 is the maximum for 8mp)

I managed to cure the frame drop by putting an additional spare disk in the NVR, setting the storage mode to group and assigning the two 2386's on their own to the second disk.

 

[Dan]

Hi @JB1870

We had been testing at several different max. bitrate levels (from as low as 2,000 right up to the max. 16,000) and we found the same as you that the camera was ignoring the maximum bitrate and going as high as it needed to go. Just as I was writing this it came to mind that the possible issue was the camera and NVR settings not syncing up as our test camera was on a local network switch and we were accessing the video settings from a direct monitor, when I logged directly into the camera with a browser I found the bitrate settings were different and so I synced the NVR and camera settings up and then it started paying attention and actually limiting the bitrate.

In regards to jump in frame rate you saw when dropping the resolution, the 2386G2 cameras do support up to 25fps but only when set to the lower resolution and in the case of these cameras, we had to set ours to 4MP resolution before 25fps was offered in the settings so I am not sure why you were seeing the jump to 22fps in 6MP resolution. We did notice after every bitrate adjustment we made that the frame rate did jump around from 14-16fps but then after few seconds settled to 15fps.

 

[JB1970]

Hi @JB1870

We had been testing at several different max. bitrate levels (from as low as 2,000 right up to the max. 16,000) and we found the same as you that the camera was ignoring the maximum bitrate and going as high as it needed to go. Just as I was writing this it came to mind that the possible issue was the camera and NVR settings not syncing up as our test camera was on a local network switch and we were accessing the video settings from a direct monitor, when I logged directly into the camera with a browser I found the bitrate settings were different and so I synced the NVR and camera settings up and then it started paying attention and actually limiting the bitrate.

In regards to jump in frame rate you saw when dropping the resolution, the 2386G2 cameras do support up to 25fps but only when set to the lower resolution and in the case of these cameras, we had to set ours to 4MP resolution before 25fps was offered in the settings so I am not sure why you were seeing the jump to 22fps in 6MP resolution. We did notice after every bitrate adjustment we made that the frame rate did jump around from 14-16fps but then after few seconds settled to 15fps.

Thanks Dan. I'll take a look directly in the camera as well. I have noticed that if I set the bitrates in the NVR to General and 10240 in the dropdown, when I go back in later the bitrate is still 10240 but it's changed itself from General to Custom but doesn't affect anything else. Just another bug to add to the list. I've also noted that in the I series NVR maintenance > Camera menu - all AcuSense G2 cameras show that Motion Detection is "disabled" in the summary page even though it is enabled and working correctly otherwise.