HLS/mpeg dash output

[saranrapjs]

Watching the Peer to Peer Web stream yesterday (nice work on that!) I was struck that it wouldn't be terribly difficult for Hypercast to pump out an m3u/mpd playlist file in addition to the webm files. I see this as having a couple advantages:

• my impression is that all of the non-native implementations of HLS/mpeg-dash use MediaSource under the hood (e.g. Shaka), so the viewer code could potentially be made to consume these playlist files instead with hopefully not too much effort
• spitting out playlist files would (potentially) allow non-browser clients to consume the live feed more easily as well. i was reading this post about non-browser support for the two live streaming formats in wide use, as part of looking at what it would look like to setup a Raspberry pi to play a live stream produced by hypercast. the native clients aren't super well-supported, but i like the idea that you could consume a hypercast in a device-independent way!

here's the catch, though: i'm pretty sure none of the container formats that MediaRecorder is capable of recording to are supported by HLS 😢 i'm using this chart plus MediaRecorder.isTypeSupported to test that out, though. it looks like, on the viewer-side, MediaSource does supported some mp4 container formats that HLS supports, but that may or may not be helpful

anyways, curious to hear thoughts on whether or not this would be an interesting thing to add to hypercast! i'd be happy to spec out a branch