#7 Local playback architecture overhaul

[Robert Kaye]

I think "Transmitter" is the correct place for this, since it's
essentially
about rewriting the local playback to be more like a
transmitter... Since the local playback mechanism relies on
successive invocations of freeamp
in mpg123 mode, there are noticeable lags between songs
(The Wall is, of course,
the canonical test for this :) ). Furthermore, using
freeamp/mpg123 as the
output mechanism makes it impossible to implement a
reasonable "pause" in the
stream, or to interrupt (ie: Next Track) the playback with
decent
responsiveness... I'm unfortunately unfamiliar with what
extant community work there is in
decompression / playback "pipeline" architecture, but
something like that would
be very well-suited to this. Basically, Obs. should be able
to open up files and
shovel data at one pipe, and control information at another
pipe. When Obs.
wants to pause the output, or stop it and skip to the next
chunk, it should sent
control messages to that effect. That backend pipe can
then be outputting through decompressors, or spitting out
RTP, or SHOUTcast, or whatever. Those are my vague
thoughts, anyway.