At Tue, 17 Mar 2009 13:30:12 +0200, Maxim Levitsky wrote: > > On Tue, 2009-03-17 at 08:57 +0100, Takashi Iwai wrote: > > At Tue, 17 Mar 2009 02:52:19 +0200, > > Maxim Levitsky wrote: > > > > > > On Mon, 2009-03-16 at 22:22 +0100, Andreas Mohr wrote: > > > > Hi, > > > > > > > > On Mon, Mar 16, 2009 at 09:28:39PM +0100, Takashi Iwai wrote: > > > > > At Mon, 16 Mar 2009 19:06:38 +0100, > > > > > Andreas Mohr wrote: > > > > > > I just tried connecting a headset and switching to E-Mic. > > > > > > What I can say is: > > > > > > - opposite levels does NOT happen there (E-Mic is "analog micro"-based, right?) > > > > > > - leaving E-Mic unplugged will actually record from i-Mic (due to properly > > > > > > working EAPD mechanism, right?) > > > > > > > > > > The record from mic-jack is via analog path. The phase-inversion > > > > > appears only for digital-mic, AFAIK. > > > > > > > > Thought so. > > > > > > > > > > One question still: is this a hardware defect (i.e. could this possibly > > > > > > be swapped cables of the microphone connector in this model or so? > > > > > > Not plausible but...), or is this an existing property > > > > > > of the HDA's dig-mic base? You indicated it's the latter I think... > > > > > > > > > > My guess is that it's a hardware implementation. > > > > > Maybe for the noise suppression via mic array. > > > > > > > > Not sure what this means. > > > > > > > > > The question is whether the left / right channels recorded from > > > > > digital mic are really raw data, or they are for modified data > > > > > (for differential, etc)... It's hard to guess without the actual > > > > > data. > > > > > > > > I don't quite follow you here. Is there anything I could do about this? > > > > > > > > Thanks, > > > > > > > > Andreas > > > > > > > > > What about exposing the i-mic as a mono only device to userspace? > > > It is mono after all? > > > > No, it's a mic-array. And HD-audio cannot handle a mono stream. > No problem. > Lets just lie to usespace that it is mono, in kernel driver can pick one > of channels? No, the hardware provides only the stereo streams, so the driver, too. The downmixing is the job of the user-space. For example, try the patch to alsa-lib I sent in my previous post. > Maybe this is an array, but this doesn't explain the 'quality' of it. > It is so low (in windows too). Properly using the mic-array would reduce the noise fairly well. XP has no mic-array support, IIRC. Of course, it's possible that Aspire* have badly equipped mic arrays that don't help much noise suppression... Takashi -- To unsubscribe from this list: send the line "unsubscribe kernel-testers" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
