[Vorbis-dev] Multi-channel labels in Vorbis comments

[Daniel James]

Hi Monty,

> The RockBand/GuitarHero franchises are using massively multitrack ogg
> files (.mogg) that are similar to the proposed use case.  I hadn't
> looked at them to see if they were a general purpose solution or were
> just hard-wired arrangements for specific games.

I found some more details here:

http://sites.google.com/site/mahoppiangoon/customrbdlc

There is a tool called ogg2mogg which inserts the non-standard headers
required for RockBand into a multichannel Vorbis file. However it seems
a RockBand project contains several other files, including text metadata
and MIDI, presumably so that the timing of musical notes in each channel
can be represented on the gamer's screen.

For DJ'ing purposes, if we require all tracks to be supplied with MIDI
data, that is going to make creation of tracks more time-consuming.
However it would open up new possibilities, such as taking the bassline
from a track and playing it live through a completely different
instrument, or sending that MIDI data to a real time VJ application.

I suppose one way to handle this would be to allow for MIDI in the stem
DJ'ing specification, but make it non-mandatory. This would allow us to
support pre-1980s tracks where original MIDI data is not available. For
example I might be able to make a reasonably accurate pastiche in MIDI
of a Marvin Gaye track, but it would take a long time to get right
because of all the human variables in those analogue recordings.

Cheers!

Daniel