Hikvision Onvif doorbell - how did OpenHab get it working?

[BartButenaers]

Hi folks,

Having my own ip video doorbell is already since day one on my todo list. But most bells need a cloud subscription, and I'm not going to pay somebody to look at my own pictures from my own camera... The DoorBird doorbell could solve this, but it is pretty expensive...

Found here some doorbells with Onvif support, like e.g. the DS-HD1 from Hikvision:

Seems that the Openhab community managed to get it running somehow, but my Openhab knowledge is too small to understand how it works. So if anybody can tell me, that would be great!

The camera supports Onvif and RTSP streaming. But I don't understand how the dual way audio (via ffmpeg perhaps?) works ... And also not sure how I could use my node-red-contrib-onvif-nodes to get this working ....

I have come to the painful conclusion that I can't do both: developing nodes for the community and experimenting with this kind of stuff... So would be nice if some people could join this discussion with their knowledge and experience!

Thanks!
Bart

[ghayne]

Bart, the link to your Onvif nodes was a revelation! I have been searching for something like this, I never thought to search here! Doh

[BartButenaers]

Garry,
Keep in mind that these nodes are not published on npm yet. And the reason is very simple: I don't have time to fix the known issues. So keep in mind that it is not 100% working! And I'm not going to publish those on NPM when I have no time to help everybody, because every brand of cameras has it own onvif issues. Especially the cheap chinese ones...
But don't want to go further off-topic now about this!!!!!

[BartButenaers]

Seems that the Onvif streaming spec requires an RTSP stream from the camera to the client, but there should also be an audio backchannel for audio from the client towards the camera.

And based on this discussion, it seems that ffmpeg does NOT support such backchannels.
So I'm stuck again ...

[ristomatti]

Not sure if this could help but I found this discussion with a quick search https://github.com/Sunoo/homebridge-camera-ffmpeg/issues/174.

On a quick glance it seemed to be about ffmpeg and two-way audio.

[BartButenaers]

@ristomatti

On a quick glance it seemed to be about ffmpeg and two-way audio.

Hi Ristomatti,
So there could be two ways to do this, if I understand correctly:

• Use an RTSP server that supports a back channel, like e.g. gst-rtsp-server which is based on gstreamer.
• Use two separate ffmpeg processes, one for each direction.

Not sure at the moment which is the best way to go ...

[ristomatti]

Sounds like quite a mess regardless.