Festival and OSS/ALSA (was: [Kenny Hitt] Re: Is Debian appropriate for accessibility?)
Unfortunately, good and cheap sound cards are not commonly available
today. So most Linux users have to base their sound output on ALSA
Here is how to do it on a Debian GNU/Linux system:
- Tell all applications to use ALSA instead of OSS.
- If it is not possible (as with Festival that can only use OSS dsp
devices), use the aoss wrapper. Install the alsa-oss package and run
the OSS-only applications with that wrapper, e.g. `aoss festival'.
(There's no need to arrange this in Speech Dispatcher as Speech
Dispatcher uses Festival only for synthesizing the sound, not playing
- If you don't have /proc/asound on your system, the aoss script won't
work. Remove the checking condition in the script in such a case
(yes, I should file a bug report about this).
- Remove the oss emulation kernel modules in order to prevent OSS
applications hijacking your sound device.
- Enforce using dmix system-wide. I do this by putting something like
the following into /etc/asound.conf:
# Setup the dmix plugin
ipc_key_add_uid false # let multiple users share
ipc_perm 0666 # IPC permissions for multi-user sharing
pcm "hw:0,0" # change this if you use other sound device
# Use dmix as the default device
# Redirect all OSS devices
Note it may be necessary to put additional hardware specific options
to the pcm.dmixer section in order to make it work with some audio
You may need to reboot after changing the asound.conf file.