Video sync with HIKvision IPcams (tech query about RTCP)

[Mobiquitus 0]

Hello

 

we have been doing custom NVR SW since many years. We have been always struggling with HIKvision way of implementing international standards.

 

In current cases I am having huge problem to keep in sync video/audio streams from some HIK Ipcams. The issue is down to the fact that HIK firmware doesn't send "RTCP sender request" packets hence I have no way to keep the video in sync since I am using HIK timestamp for that.

 

Firmware tested:

v.5.0.2 build 130709 (faulty)

v.5.1.0 build 131202 (faulty)

v.5.2.0 build 140721 (faulty)

v.5.1.6 build 140412 (correct)

 

Is there someone aware of such issue ?

 

THX

[Mobiquitus 0]

Hi

 

It's hard to believe that no one has had the same problem. HIK's RTCP implementation is not following the international standards hence it is not possibly to correctly sync audio and video when doing playback with such devices. Is this the right forum where to ask such tech questions or should I try somewhere else ?

THX

[40th Floor 0]

Right, probably not the best place. Where else have you asked?

 

Are you depending on the NTP timestamp from the SR packet? Well there's your problem. I'll mention a couple of reason why I think that.

 

1. Not all IP cameras will send SR. Big one.

 

2. NTP times, or the time-of-day known to the camera, is an uncertain quality. I've got a D* camera that, while it gets NTP from a time server just fine, is always off up to 30 seconds, sometimes more, as if it held that time until it finished starting up and then set itself to that time.

 

I can see how the SR NTP timestamp could be a good source of sync'ing cameras, especially if they are not at the same location where you could have different packet delays between cameras. However, since the cameras themselves can be wildly off, much more than any delay, it means it's not dependable, even if all cameras send SRs as you expect.

[Mobiquitus 0]

HI

 

finally someone who knows this stuff.

Yes I rely on those SR packets to sync the playback of the video. I use my own NTP server inside the same LAN and clock has never been a problem this way (no Inet connection in my cases).

ONVIF uses SR packets and since I am using HIKvision ONVIF cams (claimed so) I was expecting they followed ONVIF standard but it seems they don't !

THX 4 help