Flash video playback is currently only a proof-of-concept and should be considered EXTREMELY experimental, which is why it has been disabled by default.

It currently expects that ffmpeg is installed and compiled with mp3 support, and that the recordings files are accessible to your webserver userid. It probably won't work with Nupplevideo files, and in the end, it may just not work at all (or maybe even worse).

Enable this feature at your own risk, and don't expect too much official help until it has left the experimental phase.