Re: microphone

[deloptes <deloptes@yahoo.com>]

Adam Hardy wrote:

> Jasper on 25/05/10 17:38, wrote:
>> You have more than one sound-device in your system.
>> Maybe this helps: http://alsa.opensrc.org/index.php/ALSA_device_labels
> 
> Surely my microphone input should be listed?
> 
> adam@isengard:~$ arecord -L
> default:CARD=Intel
>      HDA Intel, ALC882 Analog
>      Default Audio Device
> front:CARD=Intel,DEV=0
>      HDA Intel, ALC882 Analog
>      Front speakers
> surround40:CARD=Intel,DEV=0
>      HDA Intel, ALC882 Analog
>      4.0 Surround output to Front and Rear speakers
> surround41:CARD=Intel,DEV=0
>      HDA Intel, ALC882 Analog
>      4.1 Surround output to Front, Rear and Subwoofer speakers
> surround50:CARD=Intel,DEV=0
>      HDA Intel, ALC882 Analog
>      5.0 Surround output to Front, Center and Rear speakers
> surround51:CARD=Intel,DEV=0
>      HDA Intel, ALC882 Analog
>      5.1 Surround output to Front, Center, Rear and Subwoofer speakers
> surround71:CARD=Intel,DEV=0
>      HDA Intel, ALC882 Analog
>      7.1 Surround output to Front, Center, Side, Rear and Woofer speakers
> iec958:CARD=Intel,DEV=0
>      HDA Intel, ALC882 Digital
>      IEC958 (S/PDIF) Digital Audio Output
> null
>      Discard all samples (playback) or generate zero samples (capture)

3 steps to find out and test a microphone on linux with alsa


1) find out cards and inputs

shell> cat /proc/asound/cards
 0 [Intel          ]: HDA-Intel - HDA Intel
                      HDA Intel at 0xff950000 irq 22
 1 [HVR900         ]: USB-Audio - WinTV HVR-900
                      WinTV HVR-900 at usb-0000:00:1a.7-3, high speed
 2 [Webcam         ]: USB-Audio - Philips SPC 1000NC Webcam
                      Philips CE Philips SPC 1000NC Webcam at
usb-0000:00:1a.7-5.4, high speed

 => I'm going to use the Webcam built in mic => card # 2

2) find out the input

shell> cat /proc/asound/devices
  0: [ 0]   : control
  1:        : sequencer
  6: [ 0- 2]: hardware dependent
  7: [ 0- 3]: hardware dependent
 16: [ 0- 0]: digital audio playback
 17: [ 0- 1]: digital audio playback
 19: [ 0- 3]: digital audio playback
 24: [ 0- 0]: digital audio capture
 32: [ 1]   : control
 33:        : timer
 56: [ 1- 0]: digital audio capture
 64: [ 2]   : control
 88: [ 2- 0]: digital audio capture


=> my input is the capture on the second card

 88: [ 2- 0]: digital audio capture

3) so no we can test the mic

shell> arecord -c1 -Dplughw:2,0 -f cd -vv /dev/null

kind regards