If you're using JW PLayer HTML5 is automatic and they also offer their own streaming platform, bitsontherun, which will automatically resolve most of your issues. However, it's not cheap. Otherwise there are a number of issues you need to consider:
- how many streams you will serve/day
- total bandwidth
- do you want to protect videos from leeching, direct download, using in 3rd party sites or apps (increases your bandwidth cost)
I don't use wordpress, but in reading about different things, it seems like wordpress often has compatibility issues with newer video technologies. I would stay away from that if you can already do php , css, html
