[gentoo-user] ALSA mixer as a capture device with Intel HDA cards

[gentoo-user] ALSA mixer as a capture device with Intel HDA cards

[Nuno J. Silva]

Hello,

Today, I got a bit curious, and wanted to get some sound from a computer
which does not have any speakers at the moment. Mostly for fun, I
thought about using arecord and then listening to the file.

I decided to have a look around the mixer, with no luck.  I remember
alsamixer showing an option to use the PCM mixer as a capture device,
but this was with other, older cards (possibly an ESS Maestro or a
Creative Enqsonic). Now, for this "Intel HDA" card, I don't see an
option to select the card's own output as the input stream.

From what I see, I'd simply assume this means the new card does not have
support for this in the hardware mixer, but I wonder whether I'm missing
something obvious. The card is listed, in lspci, as 

   Audio device: NVIDIA Corporation MCP72XE/MCP72P/MCP78U/MCP78S High
   Definition Audio (rev a1)

And alsamixer lists it as 

   Card: HDA NVidia
   Chip: Realtek ALC887  

Any hints? 

-- 
Nuno Silva (aka njsg)
http://njsg.sdf-eu.org/

[gentoo-user] Re: ALSA mixer as a capture device with Intel HDA cards

[»Q«]

On Sun, 23 Dec 2012 01:59:50 +0200
nunojsilva@ist.utl.pt (Nuno J. Silva) wrote:

> Hello,
> 
> Today, I got a bit curious, and wanted to get some sound from a
> computer which does not have any speakers at the moment. Mostly for
> fun, I thought about using arecord and then listening to the file.
> 
> I decided to have a look around the mixer, with no luck.  I remember
> alsamixer showing an option to use the PCM mixer as a capture device,
> but this was with other, older cards (possibly an ESS Maestro or a
> Creative Enqsonic). Now, for this "Intel HDA" card, I don't see an
> option to select the card's own output as the input stream.
> 
> From what I see, I'd simply assume this means the new card does not
> have support for this in the hardware mixer, but I wonder whether I'm
> missing something obvious. The card is listed, in lspci, as 
> 
>    Audio device: NVIDIA Corporation MCP72XE/MCP72P/MCP78U/MCP78S High
>    Definition Audio (rev a1)
> 
> And alsamixer lists it as 
> 
>    Card: HDA NVidia
>    Chip: Realtek ALC887  
> 
> Any hints? 

I have exactly same question/problem, but with Realtek ALC275, not
on an nVidia card.  As far as I can tell, I only have one capture option
in alsamixer, and toggling it on only captures sound picked up by the
microphone.

Here's my output of amixer: <http://remarqs.net/misc/amixer.txt>

And a screenshot of alsamixer's capture settings:
<http://remarqs.net/misc/alsamixer-capture.png>

[gentoo-user] Re: ALSA mixer as a capture device with Intel HDA cards

[Nuno J. Silva]

On 2012-12-23, »Q« wrote:

> On Sun, 23 Dec 2012 01:59:50 +0200
> nunojsilva@ist.utl.pt (Nuno J. Silva) wrote:
>
>> Hello,
>> 
>> Today, I got a bit curious, and wanted to get some sound from a
>> computer which does not have any speakers at the moment. Mostly for
>> fun, I thought about using arecord and then listening to the file.
>> 
>> I decided to have a look around the mixer, with no luck.  I remember
>> alsamixer showing an option to use the PCM mixer as a capture device,
>> but this was with other, older cards (possibly an ESS Maestro or a
>> Creative Enqsonic). Now, for this "Intel HDA" card, I don't see an
>> option to select the card's own output as the input stream.
>> 
>> From what I see, I'd simply assume this means the new card does not
>> have support for this in the hardware mixer, but I wonder whether I'm
>> missing something obvious. The card is listed, in lspci, as 
>> 
>>    Audio device: NVIDIA Corporation MCP72XE/MCP72P/MCP78U/MCP78S High
>>    Definition Audio (rev a1)
>> 
>> And alsamixer lists it as 
>> 
>>    Card: HDA NVidia
>>    Chip: Realtek ALC887  
>> 
>> Any hints? 
>
> I have exactly same question/problem, but with Realtek ALC275, not
> on an nVidia card.  As far as I can tell, I only have one capture option
> in alsamixer, and toggling it on only captures sound picked up by the
> microphone.
>
> Here's my output of amixer: <http://remarqs.net/misc/amixer.txt>
>
> And a screenshot of alsamixer's capture settings:
> <http://remarqs.net/misc/alsamixer-capture.png>

Very similar to my desktop -- I have *two* capture settings, but I
suppose that's because the card has two microphone inputs (front and
rear) along with line in, and they probably wanted to allow capture from
more than one source at the same time. So, other than another capture
option and an option to pick the source, it seems to be the same.

I'll see if I can get an older PCI card to try this with, and see if it
gives me the capture option I want. 

-- 
Nuno Silva (aka njsg)
http://njsg.sdf-eu.org/