[alsa-devel] Verifying mixer dB data/Invalid dB data from USB cards, especially Aureon 5.1 MkII

Lennart Poettering mznyfn at 0pointer.de
Wed Feb 17 14:06:12 CET 2010

On Wed, 17.02.10 10:04, Jaroslav Kysela (perex at perex.cz) wrote:

> The second question is if the represented dB range and scale reported from 
> the driver (hardware and audio chip datasheets) really matches the 
> hardware and how we can measure these values. I suspect a lot of trouble 
> here, because the analog parts of soundcards might have strange curves - 
> it's probably thing you deal with in PA now.

Yes, that is indeed the problem.

For PA I don't care whether the dB curve reported by ALSA might be
shifted relative to some reference level, what matters is that
otherwise the curve reflects properly how volume increases with higher
discrete volume settings.


Lennart Poettering                        Red Hat, Inc.
lennart [at] poettering [dot] net
http://0pointer.net/lennart/           GnuPG 0x1A015CC4

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