Specifications

For more information see the 4Front Technologies web page at http://www.opensound.com/. I wrote a review
of OSS/Linux in the June 1997 issue of Linux Journal.
6.30. Sox/Play/Vplay reports "invalid block size 1024"
A change to the sound driver in version 1.3.67 broke some sound player programs which (incorrectly)
checked that the result from the SNDCTL_DSP_GETBLKSIZE ioctl was greater than 4096. The latest sound
driver versions have been fixed to avoid allocating fragments shorter than 4096 bytes which solves this
problem with old utilities.
6.31. The mixer settings are reset whenever I load the
sound driver module
You can build the sound driver as a loadable module and use kerneld to automatically load and unload it.
This can present one problem − whenever the module is reloaded the mixer settings go back to their default
values. For some sound cards this can be too loud (e.g. SoundBlaster16) or too quiet. Markus Gutschke
(gutschk@uni−muenster.de) found this solution. Use a line in your /etc/conf.modules file such
as the following:
options sound dma_buffsize=65536
post−install sound /usr/bin/setmixer igain 0 ogain 0 vol 75
This causes your mixer program (in this case setmixer) to be run immediately after the sound driver is
loaded. The dma_buffsize parameter is just a dummy value needed because the option command requires
a command line option. Change the line as needed to match your mixer program and gain settings.
If you have compiled the sound driver into your kernel and you want to set the mixer gains at boot time you
can put a call to your mixer program in a system startup file such as /etc/rc.d/rc.local.
6.32. Only user root can record sound
By default the script in Readme.linux that creates the sound device files only allows the devices to be read by
user root. This is to plug a potential security hole. In a networked environment, external users could
conceivably log in remotely to a Linux PC with a sound card and microphone and eavesdrop. If you are not
worried about this, you can change the permissions used in the script.
With the default setup, users can still play sound files. This is not a security risk but is a potential for
nuisance.
6.33. Is the sound hardware on the IBM ThinkPad
supported?
The Linux Sound HOWTO
6.30. Sox/Play/Vplay reports "invalid block size 1024" 26