ERROR Failed to start stream: input to ffmpeg was provides as stdin, but the process does not support stdin.
Only finding one prior reference to the error in the issue title, with no clear resolution. On closer inspection of open issues, this _may_ be related to #53.

I am running the plugin on HOOBS, running on a Raspberry Pi 4. Configuration appears to be working correctly otherwise: I'm receiving motion notifications through my Home app, and I am able to view the camera's live stream directly. This appears to affect only the video capturing attached to those motion notifications.

The device in question is the Google Nest Doorbell (battery). All software versions are current: HOOBS 4.2.8, bridge version 1.1.9.

Full HOOBS logs:

```
1:04:44 PM Google Nest Sdm Bridge Loaded plugin 'homebridge-google-nest-sdm'
1:04:44 PM Google Nest Sdm Bridge Loading 1 platforms...
1:04:44 PM Google Nest Sdm Bridge homebridge-google-nest-sdm Loading accessory from cache: Entryway Doorbell
1:04:45 PM Google Nest Sdm Bridge Bridge is running on port 51886.
1:04:47 PM Google Nest Sdm Bridge homebridge-google-nest-sdm Restoring existing accessory from cache: Entryway Doorbell
1:11:41 PM Google Nest Sdm Bridge homebridge-google-nest-sdm ERROR Failed to start stream: input to ffmpeg was provides as stdin, but the process does not support stdin.
1:11:55 PM Google Nest Sdm Bridgehome bridge-google-nest-sdm ERROR Failed to start stream: input to ffmpeg was provides as stdin, but the process does not support stdin.
1:12:08 PM Google Nest Sdm Bridge ERROR [HDS ::ffff:192.168.1.138] Recording download stream 1 is still awaiting generator although stream was closed 10s ago! This is a programming mistake by the camera implementation which prevents freeing up resources.
1:12:08 PM Google Nest Sdm Bridge ERROR [HDS ::ffff:192.168.1.138] Recording download stream 1 is still awaiting generator although stream was closed 10s ago! This is a programming mistake by the camera implementation which prevents freeing up resources.
1:12:12 PM Google Nest Sdm Bridge ERROR [HDS ::ffff:192.168.1.138] Recording download stream 1 is still awaiting generator although stream was closed 10s ago! This is a programming mistake by the camera implementation which prevents freeing up resources.
1:12:12 PM Google Nest Sdm Bridge ERROR [HDS ::ffff:192.168.1.138] Recording download stream 1 is still awaiting generator although stream was closed 10s ago! This is a programming mistake by the camera implementation which prevents freeing up resources.
```

HOOBS runs each bridge in its own container. Could that be the culprit here?