in 0.2.0-beta4 video recording appears error-prone

i've opted for the nightly builds on F-Droid. i'm now running 0.2.0.-alpha4 (117)

during testing, i've enabled video recording for a relatively short duration... i've tried 15 seconds and 30 seconds. when camera events are triggered now, the following result will happen:

1. the device display says "RECORDING" in red
2. the device creates a whole mess of JPG images that don't really show much
3. the device seems to /try/ to record video files. but they are never 15 or 30 seconds or whatever i've configured
4. the video files that get recorded tend to be about 2 or 3 seconds only, and similarly don't really show anything useful
5. often, other video files are also saved, but they are broken/have no frames/etc

so as a monitoring tool, unfortunately this isn't really working for me now. arg.

Reproduce a camera event with video recording configured for 15 or 30 seconds on the reported Android build, then inspect the generated JPG and video files. Done means the recording produces valid video with useful frames and approximately the configured duration, without broken extra files.

Written by the indexing model from the issue text.