I am encountering a similar issue when deploying the app on streamlit cloud: Upon pressing “start”, the webcam connects, the loader spins for a few seconds and then the webcam disconnects. It works perfectly on my local machine though.
Here is the app.py: smarteye_app/app.py at main · Inc0mple/smarteye_app · GitHub
And the logs when attempting to connect to the webcam on streamlit cloud:
2022-01-20 01:40:01.973 Track video received
2022-01-20 01:40:01.973 Set <aiortc.rtcrtpreceiver.RemoteStreamTrack object at 0x7fd1594fca00> as an input video track with video_processor <class 'streamlit_webrtc.process.AsyncVideoProcessTrack'>
2022-01-20 01:40:01.973 Add a track <streamlit_webrtc.process.AsyncVideoProcessTrack object at 0x7fd1594d9400> of kind video to <aiortc.rtcpeerconnection.RTCPeerConnection object at 0x7fd15b76afa0>
2022-01-20 01:40:01.995 Connection(4) Check CandidatePair(('10.13.0.42', 52746) -> ('172.30.64.1', 54310)) State.FROZEN -> State.WAITING
2022-01-20 01:40:01.995 Connection(4) Check CandidatePair(('10.13.0.42', 52746) -> ('192.168.50.164', 54311)) State.FROZEN -> State.WAITING
2022-01-20 01:40:01.995 ICE connection state is checking
2022-01-20 01:40:01.995 Connection(4) Check CandidatePair(('10.13.0.42', 52746) -> ('172.30.64.1', 54310)) State.WAITING -> State.IN_PROGRESS
2022-01-20 01:40:02.504 Connection(4) Check CandidatePair(('10.13.0.42', 52746) -> ('192.168.50.164', 54311)) State.WAITING -> State.IN_PROGRESS
2022-01-20 01:40:20.490 ICE connection state is closed
2022-01-20 01:40:33.604 Exception in callback Transaction.__retry()
handle: <TimerHandle when=3161090.544572577 Transaction.__retry()>
Traceback (most recent call last):
  File "/usr/local/lib/python3.8/asyncio/selector_events.py", line 1048, in sendto
    self._sock.sendto(data, addr)
AttributeError: 'NoneType' object has no attribute 'sendto'

Any help would be appreciated!