Support RTSP stream

[arsaboo]

With the upcoming stream component (in 0.90) in Home Assistant that only supports RTSP streams without transcoding, I was wondering if we should consider providing an RTSP stream.

Surveillance Station supports RTSP stream and we should consider implementing that.

[pergolafabio]

But, why not make a camera then in HA with the rtsp path? Then you have it already

[arsaboo]

Sure, I can manually add individual cameras and maybe that is the way to go. I was thinking that the cameras that are added with the component could use RTSP.

[hunterjm]

I think this is a valid issue. Currently, _video_stream_url is hardcoded to the MJPEG url. The documentation specifies a GetLiveViewPath method in section 2.3.4.18 which this method could utilize. That would give us the ability to pass in the already defined video_format and request the stream path we want from Synology.

The advantage would be to continue to use the Synology component that adds all of the cameras instead of defining each as a "Generic IP Camera" in the configuration. If this library is updated, I can easily add support in Home Assistant.

[arsaboo]

Looks like @alekslyse did that in his (now closed) PR. Wondering if we should re-open that PR