[linux-audio-dev] SNDCTL_DSP_CHANNELS problem setting to mono

Overcast, Isaac Overcasi at evergreen.edu
Fri Jul 18 17:03:00 UTC 2003


Hello all.

Here's the setup:

HW -
stoopid gateway e-3400
onboard AC'97 audio (blech!)

SW -
RedHat 9.0
portaudio (www.portaudio.com)

Now, the problem is portaudio is failing to play mono files. Portaudio lib
code is making an ioctl call that looks like this:

<snip>

int numChannels = 1 ;
ioctl( deviceHandle, SNDCTL_DSP_CHANNELS, &numChannels )

</snip>


This call doesn't fail, but when it returns 'numChannels' == 2. Portaudio
detects this and promptly dies.

Now, i just can't figure out if the problem is the onboard sound device is
just so crappy that it doesn't bother to support mono, or if there is some
wierd kernel module i can build that will fix this issue.


This isn't the worlds biggest deal, but it's just bugging me, you know?

thanks
-isaac




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