Bad capture device in ALSAMixer or device missing from "arecord -l" ?

starfry · 2015-09-01 15:40:41

My need to capture some external audio/video has given me a need to aquaint with ALSA capture devices. I have an onboard sound card that reports itself to ALSA as "HDA Intel". When I enquire about its capture devices I am told about two:

$ arecord -l
**** List of CAPTURE Hardware Devices ****
card 0: Intel [HDA Intel], device 0: AD1989B Analog [AD1989B Analog]
  Subdevices: 1/1
  Subdevice #0: subdevice #0
card 0: Intel [HDA Intel], device 2: AD1989B Alt Analog [AD1989B Alt Analog]
  Subdevices: 1/2
  Subdevice #0: subdevice #0
  Subdevice #1: subdevice #1

I understand from this output that I have two capture devices and they are called "hw0,0" and "hw0,2" being devices 0 and 2 on card 0. I don't know what subdevices are. There is no device 1 listed.

However, the ALSA mixer displays three "capture" devices on the capture (press F4) screen. They're called "Capture", "Capture1" and "Capture2". By playing around I've discovered that "Capture" is "hw0,0" and "Capture1" is "hw0,2" Both can be independently assigned to one of several input sources (front mic, rear mic, Line, CD, etc) and capturing works fine. There appears to be no way to use "Capture2".

I'm trying to understand if "Capture2" displayed by error in ALSAmixer or if is there a device missing from "arecord -l" ? It looks to me like there ought to be a "hw0,1". I don't know if I have something wrong with my setup or if how it is is how it should be. I did see another thread that described the same two capture devices, so I expect what I have is right even though it doesn't look that way to me.

Any pointers appreciated...

V1del · 2015-09-01 17:17:51

Capture2 is the subdevice 1 of device 2 and if you don't have any issues you can probably ignore it, likely an additional port that isn't hooked up to anything on your pc or similar

Last edited by V1del (2015-09-01 17:19:13)

starfry · 2015-09-01 19:35:18

Ah, right. Thanks for explaining that. I haven't been able to find any explanation of what subdevices are. I guess I could just ignore it, but I'd like to understand if possible. Do you know if there's any way to identify what that subdevice might be (just for my curiosity's sake) ?

V1del · 2015-09-02 07:59:42

Maybe the rear mic or something, analyze the output of http://www.alsa-project.org/alsa-info.sh should give you pointers on what it is exactly

Arch Linux

#1 2015-09-01 15:40:41

Bad capture device in ALSAMixer or device missing from "arecord -l" ?

#2 2015-09-01 17:17:51

Re: Bad capture device in ALSAMixer or device missing from "arecord -l" ?

#3 2015-09-01 19:35:18

Re: Bad capture device in ALSAMixer or device missing from "arecord -l" ?

#4 2015-09-02 07:59:42

Re: Bad capture device in ALSAMixer or device missing from "arecord -l" ?

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