[pulseaudio-discuss] Reverting ade0a6f88464d8aecf83982d400ccfc402341920

David Henningsson david.henningsson at canonical.com
Fri May 13 08:29:24 PDT 2011

On 2011-05-13 09:49, Tanu Kaskinen wrote:
> Hello,
> Should this commit be reverted?


> http://git.0pointer.de/?p=pulseaudio.git;a=commit;h=ade0a6f88464d8aecf83982d400ccfc402341920
> I don't know what problem that commit solves,but it introduces a new
> problem: if Pulseaudio requests a volume that is above 0dB in the alsa
> volume element scale, then it can easily happen that alsa will round the
> request down. That rounding is then compensated with software volume,
> which in this case is amplification. We don't want software
> amplification, or do we?

In short; if we e g have Mic Boost levels at (0dB, 20dB, 40dB and 60dB) 
and the user wants 30 dB, better have 20dB in hardware and +10dB in 
software than 40dB in hardware and -10dB in software, as the latter one 
is more likely to have digital distortion when the signal passes through 
the ADC.

There is a longer email on this list a while back, explaining more of 
the philosophy behind, but I can't seem to find it right now.

David Henningsson

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