[LAD] aqualung player request: multichannel playback

[Jörn Nettingsmeier]

hi aqualung people!


your player has been discussed as an interesting way to pave the path of
ambisonics towards world dominance, because it's cross-platform, hooks
up to jack and allows for easy integration of ladspa plugins (where we
could slip in an ambi decoder to make an easy-to-use ambi player for the
rest of us).

problem is: it won't load files with more than 2 channels.
initially, we'd need four channels for first-order b-format, and later 9
and 16 channels could be interesting. the dolby crowd might appreciate six.

how difficult would it be to implement the following?:

* make the number of jack output ports N configurable (because obviously
jack ports can't show up and go away while the program and any playlist
runs, because that makes for messy routing)

* output the channels of each soundfile in the playlist to those N
channels, padding with silence or omitting channels as needed.

this would make a spiffy .amb file player and instantly increase your
user base by at least 20 :-D
corner cases such as automatic resampling will not be important, at
least initially.

if desired, different formats could be dealt with based on number of
channels and/or additional metadata and file format guesses, and played
out to different sets of jack ports for appropriate handling. like so:
configure 2 ports for stereo: aqualung:stereo.[L|R]
configure 4 ports for ambisonics: aqualung:ambi.[W|X|Y|Z]
configure 6 ports for dolby 5.1: aqualung:5-1.[L|C|R|LS|RS|LFE]
in this simple case, aqualung could guess the correct routing based on
channel number alone. later, it would be cool to be able to configure
rule sets for routing rather than hardcoding them, such as:
suffix .amb > route to ambi
no of channels 4 > route to ambi
WAVEX flag enterprise > route to holodeck (you get the idea)...


wdyt?

btw, please remove the cc: to sursound, since it's a moderated list - i
will summarize your replies accordingly.

best,

jörn