* format url parameter supports <format>/<codec> format
* video generated in a thread to guarantee a constant fps.
* specify ofc->packet_size if rtp format is requested
* if bitrate <= 100 then the value is used to set Quality from 0-100 instead of bitrate.
Merge branch 'zms_ffmpeg' of https://github.com/Sune1337/ZoneMinder into zms_ffmpeg