On Fri, 2013-08-02 at 15:43 +0200, David Henningsson wrote: > On 08/02/2013 03:34 PM, Arun Raghavan wrote: > > On Fri, 2013-08-02 at 15:19 +0200, David Henningsson wrote: > >> Some HD-audio codecs (at least ALC269VB and ALC283) become quite noisy on > >> high Mic Boost levels. So e g, if there is a "Mic Boost" and a "Capture" > >> control, both ranging from 0 dB to +30 dB, you get better quality if > >> "Mic Boost" is 0 dB and "Capture" is +30 dB, than the other way around. > >> > >> By changing the order in the configuration files, this patch makes us prefer > >> leaving "Mic Boost" low and "Capture" high if the user selects a medium gain. > >> > >> (This is based on limited experience, and there is no guarantee that there are > >> no sound cards that work the other way around, and therefore this patch could > >> potentially regress quality on those machines. Hopefully those are fewer, so > >> this is what we should default to.) > > [...] > >> diff --git a/src/modules/alsa/mixer/paths/analog-input-headphone-mic.conf b/src/modules/alsa/mixer/paths/analog-input-headphone-mic.conf > >> index 688b8ac..3a19e01 100644 > >> --- a/src/modules/alsa/mixer/paths/analog-input-headphone-mic.conf > >> +++ b/src/modules/alsa/mixer/paths/analog-input-headphone-mic.conf > >> @@ -27,21 +27,21 @@ description-key = analog-input-microphone > >> required-any = any > >> state.plugged = unknown > >> > >> -[Element Headphone Mic Boost] > >> -required-any = any > >> -switch = select > >> +[Element Capture] > >> +switch = mute > >> volume = merge > >> override-map.1 = all > >> override-map.2 = all-left,all-right > >> > >> -[Element Headphone Mic] > >> +[Element Headphone Mic Boost] > > > > If we're doing this, might as well prefer Headphone Mic over Headphone > > Mic Boost? > > We could, but I'd rather have some sort of evidence/indication that this > will actually make a difference first. For starters, it's unusual to > have both "Headphone Mic" and "Headphone Mic Boost" on the same sound card. > > Also, we're moving this around because we have empirical experience that > hardware behaves this way, not because it is logical for hardware to do > so. Hence I'd refrain from extending the same logic to other controls. > > Btw, the reason I'm moving "Capture" rather than the Mic Boosts is that > I remember sometimes boosts are labelled "xx Mic" instead "xx Mic > Boost", even though they are boosts and could potentially work the same > way (become noisy at high levels). Fair enough. [...] > > Rest looks good to me. > > Ok, can I push this one as it is then? There's nothing stopping us from > switching "Headphone Mic" and "Headphone Mic Boost" too, if we want to > do so later. Yes, please go ahead. -- Arun
