[Sugar-devel] Getting around a (sound) device assignment problem in SoaS

Art Hunkins abhunkin at uncg.edu
Mon Sep 21 23:03:25 EDT 2009


For SoaS (Fedora Linux), there remains a problem of device assignment
involving audio out and MIDI in.

Basically, if you boot SoaS *then* plug in a MIDI controller, audio is
assigned C0D0; and MIDI, C1D0 (this is as expected). If you plug in a MIDI
controller and then boot SoaS, MIDI gets C0D0 and audio C1D0 (this is *not*
as expected!)

The latter arrangement generates the following error message (in its Log) 
when
a script is run:
Can't open device 'plughw' for audio output.

It will be necessary to either do something either in Sugar, its Csound
module, or in the python script that runs Csound to work with this issue.
So far, I've tried making manual changes to the file names (reflecting the 
"proper"
device numbers, but the error remains.

Suggestions? Especially from the Sugar side?

It would seem that Sugar needs to
look for and assign *audio* device numbers before *MIDI* device numbers. 
(Please
note that this issue does *not* exist for the native XO-1. Perhaps snooping 
around
in that code would be enlightening.) I'd appreciate the help; I'm absolutely 
lost here.

Art Hunkins



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