## Description:
For RTSP streams, set the `prefer_tcp` FFMPEG flag. This should resolve some of the "green feed" issues that some users are reporting, likely due to packets being lost over UDP on their network.
Resources: [FFMPEG protocols documentation](https://ffmpeg.org/ffmpeg-protocols.html#rtsp)
## Checklist:
- [x] The code change is tested and works locally.
- [x] Local tests pass with `tox`. **Your PR cannot be merged unless tests pass**
- [x] There is no commented out code in this PR.