Hello 2016-12-03 21:46 GMT+01:00 Ezequiel Garcia <ezequ...@vanguardiasur.com.ar>: > On 2 December 2016 at 08:05, Mauro Carvalho Chehab > <mche...@s-opensource.com> wrote: >> Em Sun, 27 Nov 2016 12:11:48 +0100 >> Marcel Hasler <mahas...@gmail.com> escreveu: >> >>> Allow setting a custom record gain for the internal AC97 codec (if >>> available). This can be >>> a value between 0 and 15, 8 is the default and should be suitable for most >>> users. The Windows >>> driver also sets this to 8 without any possibility for changing it. >> >> The problem of removing the mixer is that you need this kind of >> crap to setup the volumes on a non-standard way. >> > > Right, that's a good point. > >> NACK. >> >> Instead, keep the alsa mixer. The way other drivers do (for example, >> em28xx) is that they configure the mixer when an input is selected, >> increasing the volume of the active audio channel to 100% and muting >> the other audio channels. Yet, as the alsa mixer is exported, users >> can change the mixer settings in runtime using some alsa (or pa) >> mixer application. >> > > Yeah, the AC97 mixer we are currently leveraging > exposes many controls that have no meaning in this device, > so removing that still looks like an improvement. > > I guess the proper way is creating our own mixer > (not using snd_ac97_mixer) exposing only the record > gain knob. > > Marcel, what do you think? > -- > Ezequiel García, VanguardiaSur > www.vanguardiasur.com.ar
As I have written before, the recording gain isn't actually meant to be changed by the user. In the official Windows driver this value is hard-coded to 8 and cannot be changed in any way. And there really is no good reason why anyone should need to mess with it in the first place. The default value will give the best results in pretty much all cases and produces approximately the same volume as the internal 8-bit ADC whose gain cannot be changed at all, not even by a driver. I had considered writing a mixer but chose not to. If the gain setting is openly exposed to mixer applications, how do you tell the users that the value set by the driver already is the optimal and recommended value and that they shouldn't mess with the controls unless they really have to? By having a module parameter, this setting is practically hidden from the normal user but still is available to power-users if they think they really need it. In the end it's really just a compromise between hiding it completely and exposing it openly. Also, this way the driver guarantees reproducible results, since there's no need to remember the positions of any volume sliders. Either way, if you still think this solution is "crap", feel free to modify the patches in any way you see fit. I've wasted too much time on this already, and since I'm not being paid for it, I don't intend to put any more effort into this. Best regards Marcel -- To unsubscribe from this list: send the line "unsubscribe linux-media" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
