Sixfortyfive
He who pursues two rabbits gets two rabbits.
They've got some posts on their official blog from the past couple of weeks that goes into some detail. In short, they have (had?) two different re-encoding processes: a flexible one for desktop users that results in decent quality, and a limited one for mobile users that results in pretty shitty quality. This is part of the reason why a very limited number of channels have been available on mobile apps at any one time; they basically have to do twice the work to re-encode a stream on the two different platforms, so up until now they've just only bothered to stream the top X number of channels on mobile.I'm not too knowledgeable on the ins and outs of this stuff, but how exactly does it cannibalize stream quality for desktop?
So they've forced some recent changes onto the broadcasters so that their streams will be mobile-compatible without having to do any extra work. This allows them to kill-off the first re-encode process altogether and free up resources to get everything running smoothly on all platforms. The downside is that these changes take a pretty huge hit on video quality across the board. They don't even want you to use variable bit-rate encoding anymore, which is going to suck for everyone who doesn't have huge upload speeds.