Member Discussion

What DVRs Can Send Recorded Video Over RTSP Or ONVIF G?

Hi everybody,

We are looking onto a project where analog DVRs need to be used. The issue at hand is that we need to access the recordings in native format (h.264) streams via rtsp much the same way we access the live feed. We want exactly the same stream that the camera delivered only that instead of taking it from the camera we need to take it from the hd.

Any help or experience will be appreciated. We looked into finding some manufacturer or software developer to write a custom firmware with no luck but we are open to creative solutions.

Need this to be a DVR (ideally hdcvi) cause of cost constraints



Yes, HDCVI and HDTVI recorders do this. We covered this (RTSP and ONVIF streaming out) in this test: HD Analog DVRs With VMS Software Tested

Thanks John. I know dvr can stream live feed but what about recorded content?

My error. I misread your request.

I have not seen RTSP out for recorded video.

You would need more than RTSP for recorded video, right? You need some way to request specific times, which requires an API. This, of course, is what ONVIF Profile G hopes to do.

This is a promising statement, from Dahua regarding the ONVIF Plugfest back in March:

Being a full member of ONVIF, Dahua Technology carried out tests as a device provider for both device and client under Profile S and Profile G. During the three-day testing, there were over 5 client vendors and 15 server providers inter-testing with Dahua, including Axis, Canon, Exacq, Pelco, Samsung and others. The testing results showed that both Dahua client and server conform to the ONVIF Network Interface Specification Set, version 2.4.1; and its front-end and storage devices could support recording search/control, replay and many other functions under Profile G; and start to support new features such as video analytics, OSD in addition to basic ones such as video, PTZ, events etc.

So perhaps Dahua CVI DVR's do it already, but it is just undocumented like their other ONVIF interfaces.

Btw, ONVIF uses an extended RTSP command set for replay of recorded video. This is from the current streaming spec:

Maybe Dahua can clarify if the technology tested at Plugfest made it into the CVI line yet?

Good find. Question, though, with what ONVIF G client?

So, ONVIF showing 77 Profile G devices and 0 clients.

But Genetec must be close:

Profile G defines edge recording and Genetec offers it with a full range of functionalities, namely: Timeline, Reverse Playback, Fast-forward Playback, Keyframe-only Playback, Trickling, etc

Pelco is offering this tutorial and SOAP wrapper for G.

But as far as I can tell you can use VLC, as long as you get the URI which defines the server, channel and stream that you want. You can use absolute time-stamps in the URI to segment the playback with the range.

Depending on what the use case for the recording information actually is, and whether the OP doesn't need some interactive interface for browsing the video, e.g. batch retrieval, then it seems possible. And getting a statement from Dahua would be helpful, as it was regarding their CVI DVR capabilities and hidden ONVIF support.

But I don't think it's quite plug and play time yet.

@Ariel, is this recorded video capability driving the selection of DVR?

@chris yes we are selecting the dvr according to those features. We hired someone to do the trick and he is working on that. Will keep you guys posted. We are not going the onvif route yet.