Currently videojs player defaults to the lowest resolution, usually 160p ogg. This is pretty ugly and not what we want unless we're on a really slow mobile phone.
Instead should use some logic to pick the initial source:
format/codec preferences: vp9 > vp8 > theora resolution preferences: pick biggest that fits in the available area by default
- possibly use ogv.js-specific hack to bump down resolution if slow
- switch when going fullscreen ?