Describe the bug
ffmeg fails on video for event:

eufy-security.0 | 2021-06-20 06:00:56.295 | error | - Cancelling download...
eufy-security.0 | 2021-06-20 06:00:56.295 | error | (22107) Station: T8010N231949122D channel: 0 - Error: Error: ffmpeg    exited with code 1: unix:/tmp/eufy-security.0.2.sock: End of file
eufy-security.0 | 2021-06-20 06:00:56.295 | error | unix:/tmp/eufy-security.0.2.sock: End of file

To Reproduce
Steps to reproduce the behavior:

1. trigger movement event on eufyCam 2C
2. observe the logs

Expected behavior
The video should be downloaded and encoded correctly

Screenshots & Logfiles
eufylog.txt

Versions:

• Adapter version: 0.5.5
• JS-Controller version: 3.2.16
• Node version: 12.18.2
• Operating system: 4.19.0-9-amd64 Feature request: Support 2FA #1 SMP Debian 4.19.118-2+deb10u1 (2020-06-07) x86_64 GNU/Linux

Additional context
I stumbled upon this while testing the datapoints last_event_pic_url/html. In my case they only got updated when polling the cloud e.g. after restarting the adapter. No idea why it's working on polling. I had the impression that the last_event_pic is generated by processing the downloaded event video through ffmpeg, but I may be on the wrong track. The problem also exists when the adapter has direct access to the station.

I am not really sure if ffmeg might just fail due to missing data