On the google next hubs, are you using a web browser or the HA Android app? If so, do you have a persistent connection to HA in the companion app and does the app have all the permissions? I imagine it has all the permissions but I have seen when not having a persistent connection can cause a delay for everything. The initial sound plays before the screen comes on so it’s connected to your LAN, which makes the HA message odd. It should just connect, especially if you are using the internal IP/DNS name and not an external one over http. Although I have read of similar issues on low power ARM devices like the nspanel pro. Based on your post, it really seems like it’s just taking forever for the low power ARM CPU in the Nest to start the stream.
It’s obviously not a hardware issue based on your setup, but ffmpeg may help (see below about go2rtc) since the transcoding is CPU based and recommended for glichy streams.
I would also try the minimal version of the HA app by downloading the apk from GitHub. I know people use this on the nspanel pro to improve performance as the full version causes lots of lag. Below is from the Android APK source code page in the compile instructions. Unless you are using location tracking and getting notifications on the Google nest devices the it will run faster.
It can be downloaded from here, scroll down until you see assets for the latest release and you will see the minimal apk download. You can’t get this from HACs or the Google Play store. I only learned about this version very recently when researching if the new nspanel pro 120 was worth it or not. I really wish I had bought one at 50% off when i had the chance but I waited to long. 65, sure, 130, nope… Regardless, videos on YouTube showed it made a big performance improvement on the nspanel pro performance so worth a shot. You can probably run both at once although I could be wrong. Different apks but same version number…
Lastly, have you created a custom dashboard just for the Nest devices? Most people with the nspanel would create a new user, create a new dashboard (typically with the kiosk HACs lovelace card, although not required) and only put whats needed on that dashboard and assign it to the new user. This way, you don’t load so much onto the device at once when logging/loading HA. Might help, might not as your main issue is casting video from a camera. Probably best to use a last ditch effort.
I don’t think you can preload an RTSP stream, not unless you install go2rtc, which can be installed using a custom repository link in add ons in HA. I never installed it but per the docs it creates actual entities in HA. With WebRTC I can display streams in the dashboard, but no entities are actually created. From the docs it seemed like that is possible with [go2rtc] with the added bonus of transcoding and setting resolution and frame rate using ffmpeg (GitHub - AlexxIT/go2rtc: Ultimate camera streaming application with support RTSP, RTMP, HTTP-FLV, WebRTC, MSE, HLS, MP4, MJPEG, HomeKit, FFmpeg, etc.). I would have to re-read the docs but I know it allowed you to create names so the name:password wouldn’t show in the URL like rtsp://admin:password@someip . It can also be installed on Windows/Mac/Linux but having it as a docker add on in HA seems like the best place to install it (or docker container if not running full HA OS). Then you can leverage ffmpeg which is recommended for “glichy” streams. There is also this note about Unifi.
Ubiquiti UniFi users may want to disable HTTPS verification. Use rtspx://prefix instead ofrtsps://. And don't use ?enableSrtp suffix
streams:
sonoff_camera: rtsp://rtsp:[email protected]/av_stream/ch0
glichy_camera: ffmpeg:rtsp://username:[email protected]/live/ch00_1
The Android app has both a full flavor that uses Google Play Services to offer features like location tracking and notifications. There is also a minimal flavor that does not require Google Play Services and can be found in the releases section. The minimal flavor does not have location tracking or notifications.
