I know @Dan was investigating similar for somebody.
I recall reading that the NVR only has a total 20MB buffer capacity, which will limit the time you can achieve, number of cameras, frame rate, resolution, etc.
The post record problem has only existed since upgrading / downgrading V4 firmware, it worked ok with the previous V3 configuration.
Its very irritating as when a line crossing activation is sensed I get an instant push notification of the event but when I go to view the footage its blank.
Also when I clean the lens on the driveway camera it doesn't show me cleaning the lens, only me walking away from it, which is totally unacceptable (no post record)
I only have x2 cameras set to line crossing out of a total of x8 cameras..
Im running Firmware V4.1.64 build 190119 and my known problems are:
1.. Post/Pre record not working (Have now set to 5s and still not working)
2.. Line crossing showing no footage recorded (linkage method "Notify surveillance centre" + "trigger recording channel D*)
3.. Older 3MP DS-2CD2232-I5 camera no longer displays "Sub stream" and returns error (works ok on web browser)
4.. Email Notification still locks up NVR when you try and enter any details, hence why I use push notifications which work very well.
I've factory reset NVR several times with no difference.
Update:
DS-2CD2232-I5 substream error:
Hikvision technical traced the substream error to firmware (V5.4.5 build 170123) that the camera doesn't support, so downloaded V5.4.41 build 170312 then reset IPC and rebooted NVR and now working correctly. This camera is a "R0" series 2**2 and I had loaded the latest firmware from the R0 platform (2xx2) Euro Portal but I'm told its wrong for this camera... ah well its fixed now so moving on.
Pre & Post record not working:
In Progress
Line Crossing iVMS-4500 Playback Failure:
In Progress
Post-Pre Record Fault:
I have been in touch with Hikvision Tech Support via email and the Post/Pre record error is still there on all channels.
They have logged in directly to my NVR and checked all advanced settings which appear to be OK.
They cannot explain why this is currently happening.
Unfortunately due to work being carried out on my Skyfibre line since the end of March my Sky WAN changes on a daily basis due to a ongoing port fault at the Openreach exchange so when the Hikvision Tech tries to access my system the link is broken so I have to keep sending him new login details.
Will update when my SkyFibre is fixed (hopefully this week)
Rick89.
After enduring 7 weeks of intermittent Sky fibre unfortunately every time Hikvision’s engineer went to remotely scrutinise my system it was offline.
I now have a solid connection and should reopen the ticket.
So no not fixed yet