[alsa-devel] Alsamixertest

David Henningsson david.henningsson at canonical.com
Thu Oct 21 09:50:19 CEST 2010

On 2010-10-21 06:36, Raymond Yau wrote:
> 2010/10/4 David Henningsson<david.henningsson at canonical.com>
>> Exactly, this is a test tool that checks whether the mixer control names
>> and dB information live up to PulseAudio's expectations. That's the
>> tool's purpose.
>> What's PulseAudio' s expectation ?
> PA 's developer seem expect max_dB of all HDA codec are 0dB
> Your alsamixertest program does not test any dB range above 0dB

That's correct, I don't really know how to deal with that, and I'm not 
sure how PA deals with that either. I assume it goes above 0 dB on one 
of the volume controls when a user wants it to.

But from alsamixertest's perspective, the question is: if you do, should 
detected distortion cause an error or not?

Also alsamixertest could be expanded to trust playback and test 
recording, and then I assume this question will be even more important 
as most mic boost controls go from 0 dB to +20 dB or so (if they even 
provide dB information).

David Henningsson, Canonical Ltd.

More information about the Alsa-devel mailing list