Gentoo Archives: gentoo-user

From: nunojsilva@ist.utl.pt (Nuno J. Silva)
To: gentoo-user@l.g.o
Subject: [gentoo-user] Re: ALSA mixer as a capture device with Intel HDA cards
Date: Mon, 24 Dec 2012 13:40:20
Message-Id: 87d2xz5zzc.fsf@ist.utl.pt
In Reply to: [gentoo-user] Re: ALSA mixer as a capture device with Intel HDA cards by "»Q«"
1 On 2012-12-23, »Q« wrote:
2
3 > On Sun, 23 Dec 2012 01:59:50 +0200
4 > nunojsilva@×××××××.pt (Nuno J. Silva) wrote:
5 >
6 >> Hello,
7 >>
8 >> Today, I got a bit curious, and wanted to get some sound from a
9 >> computer which does not have any speakers at the moment. Mostly for
10 >> fun, I thought about using arecord and then listening to the file.
11 >>
12 >> I decided to have a look around the mixer, with no luck. I remember
13 >> alsamixer showing an option to use the PCM mixer as a capture device,
14 >> but this was with other, older cards (possibly an ESS Maestro or a
15 >> Creative Enqsonic). Now, for this "Intel HDA" card, I don't see an
16 >> option to select the card's own output as the input stream.
17 >>
18 >> From what I see, I'd simply assume this means the new card does not
19 >> have support for this in the hardware mixer, but I wonder whether I'm
20 >> missing something obvious. The card is listed, in lspci, as
21 >>
22 >> Audio device: NVIDIA Corporation MCP72XE/MCP72P/MCP78U/MCP78S High
23 >> Definition Audio (rev a1)
24 >>
25 >> And alsamixer lists it as
26 >>
27 >> Card: HDA NVidia
28 >> Chip: Realtek ALC887
29 >>
30 >> Any hints?
31 >
32 > I have exactly same question/problem, but with Realtek ALC275, not
33 > on an nVidia card. As far as I can tell, I only have one capture option
34 > in alsamixer, and toggling it on only captures sound picked up by the
35 > microphone.
36 >
37 > Here's my output of amixer: <http://remarqs.net/misc/amixer.txt>
38 >
39 > And a screenshot of alsamixer's capture settings:
40 > <http://remarqs.net/misc/alsamixer-capture.png>
41
42 Very similar to my desktop -- I have *two* capture settings, but I
43 suppose that's because the card has two microphone inputs (front and
44 rear) along with line in, and they probably wanted to allow capture from
45 more than one source at the same time. So, other than another capture
46 option and an option to pick the source, it seems to be the same.
47
48 I'll see if I can get an older PCI card to try this with, and see if it
49 gives me the capture option I want.
50
51 --
52 Nuno Silva (aka njsg)
53 http://njsg.sdf-eu.org/