Redo live-tv.

[Isaac Richards]

From the old bug db, #24:

Getting rid of the Ringbuffer way of timeshifting would be nice:

• Ringbuffer's slow for local access (ie, uses the network)
• Multiple semi-complicated codepaths to support the Ringbuffer and normal file access.
• Unable to save an in-progress show from the timeshifting buffer.

The idea would be to:

• Just use normal files for timeshifting.
• Automatically change to a new physical file on channel change or program change (from the guide data). Would also need to segment files every few hours, in order to allow very long programs to be timeshifted and still offer the ability to limit space used for timeshifting. Could just punt on this and just require enough recording space, though.

Basically, the recorder would need to create a chain of files to play back, and share that with the frontend on a periodic basis (store in db, send a message out to reload?). The recorder would have to be able to chunk the files based on a GOP end, so playback could continue from the beginning of an arbitrary file. The player engine would need to be able to seamlessly change from playing one file to the next. I think the hardest part would be dealing with seeking over file boundaries, but even that shouldn't be too bad.