Foolproof forward compatibility for multi-track songs

[GoogleCodeExporter]

In case we add support for more separated tracks in the future, I think we
ought to play all unrecognized oggs in the song folder as part of the
background track (song.ogg) so things are future-proof.

To make this completely bulletproof, we can add some sort of condition on
the filename that causes it to be ignored (think of preview.ogg, crowd.ogg,
or song+crowd.ogg - obviously anything similar that we might add in the
future should not be unconditionally played along with the song in versions
that don't know how to deal with it properly; since current versions by
definition already know how to deal with all such tracks that have been
defined so far, all that remains is to come up with the naming rule for
future such tracks).

If we do this, fretters with access to separated tracks can separate a
track that we have newly added support for without having to worry about
backward compatibility with versions later than when this is implemented;
some such fretters might even speculatively leave things separated when it
makes sense that we might implement support for some separated track in the
future.

Original issue reported on code.google.com by john.stumpo on 26 Dec 2009 at 10:36

[GoogleCodeExporter]

   I think this is a great idea.  I haven't had much luck with seperate tracks, so if 
it played almost all that are in the folder, it would solve that problem.  I 
also love 
the idea of expanding to other instruments, so it helps that also.

   As far as tracks to not play, I think we should come up with a system for the file 
names.  It could be mute-(filename).ogg.  So mute-crowd.ogg would not be played 
the 
whole time, only when it is asked for.  That would make things not compatible 
with 
current tracks, so maybe a mix of the two systems should be in order.

Original comment by lex...@gmail.com on 26 Dec 2009 at 7:42

[GoogleCodeExporter]

it could be a "song.ini" option if we went down that road

like a "ignore_ogg = synth.ogg; panflute.ogg"

Original comment by StagingTheUniverse@gmail.com on 27 Dec 2009 at 4:47