Live TV in the .19 World
One of the big changes to MythTV starting with 0.19 is how it handles Live TV. This page will try and outline How live TV works now, the advantages, and why you shouldn't have any fears over this new method.
You may be asking "But Isaac, WHY did you change how Live TV works? It worked fine for me in 0.18!"
The new method allows users to more easily record a show that they are watching in Live TV. The new method basically treats Live TV as a series of continuous scheduled recordings. This allows you to hit record at anytime and Myth will add the show to the Watch Recordings listing in its entirety.
I believe there was also more technical reasons to the change. From my understanding, in some way the old method was flawed and the rewrite gave Isaac and the other dev's an excuse to fix them.
How It Works
Live TV now behaves like a series of scheduled recordings. When you enter Live TV MythTV begins recording the channel as though it were a scheduled recording, except that it flags it as LiveTV in its database. If you change channels MythTV does the same on the new channel, stopping the old recording, changing channels and recording the new channel. MythTV creates a recording file according to the scheduled recording rules for recordings (Why will become clear further down) and adds this file and the show information to its database of recorded shows. As the show you are watching ends, Myth stops writing to that file and creates a new file, and new database entry for the next show, in same veign of it thinking of it like a scheduled recording, except flagged as Live TV.
Now this is the cool part. MythTV is now treating what you're watching as a scheduled recording, so if you decide you actually want to keep what your watching and hit the "Record" button all MythTV has to do is flag the recording its database as no longer being just Live TV but an actual recording.