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Re: testing microphone - how?



Rick Pasotto wrote:

> On Wed, Mar 25, 2009 at 08:38:55AM +1100, Alex Samad wrote:
>> On Tue, Mar 24, 2009 at 04:50:22PM -0400, Rick Pasotto wrote:
>> > On Tue, Mar 24, 2009 at 04:44:24PM -0400, H.S. wrote:
>> > > Alex Samad wrote:
>> > > > On Tue, Mar 24, 2009 at 05:51:37PM +0000, Lisi Reisz wrote:
>> > > >> On Tuesday 24 March 2009 17:21:06 Thorny wrote:
>> > > >>> On Tue, 24 Mar 2009 11:26:33 +0000, Lisi Reisz posted:
>> 
>> [snip]
>> 
>> > > It will record from the device specified by "-D". You can list (to
>> > > see which device number to use) your devices using:
>> > > 
>> > > ~$ arecord -l
>> > 
>> > Interesting but I have no idea what the output is telling me:
>> > 
>> > **** List of CAPTURE Hardware Devices ****
>> > card 0: V8237 [VIA 8237], device 0: VIA 8237 [VIA 8237]
>> >   Subdevices: 1/1
>> >   Subdevice #0: subdevice #0
>> > card 0: V8237 [VIA 8237], device 1: VIA 8237 [VIA 8237]
>> >   Subdevices: 1/1
>> >   Subdevice #0: subdevice #0
>> 
>> I am not a alsa expert, but the way I interpret this is there is 1
>> counds card it has 2 devices (could be 1 analogue and 1 digital) each
>> device has a set of functions / capabilities like play , record etc..
> 
> Well, I did what I should have done before -- read the man page. Turns
> out 'arecord -L' (capital L) gives better info:
> 
> -------------------
> $ arecord -L
> default:CARD=V8237
>     VIA 8237, VIA 8237
>     Default Audio Device
> front:CARD=V8237,DEV=0
>     VIA 8237, VIA 8237
>     Front speakers
> surround40:CARD=V8237,DEV=0
>     VIA 8237, VIA 8237
>     4.0 Surround output to Front and Rear speakers
> surround41:CARD=V8237,DEV=0
>     VIA 8237, VIA 8237
>     4.1 Surround output to Front, Rear and Subwoofer speakers
> surround50:CARD=V8237,DEV=0
>     VIA 8237, VIA 8237
>     5.0 Surround output to Front, Center and Rear speakers
> surround51:CARD=V8237,DEV=0
>     VIA 8237, VIA 8237
>     5.1 Surround output to Front, Center, Rear and Subwoofer speakers
> iec958:CARD=V8237,DEV=0
>     VIA 8237, VIA 8237
>     IEC958 (S/PDIF) Digital Audio Output
> null
>     Discard all samples (playback) or generate zero samples (capture)
> -------------------
> 
> So it looks like I don't have a mike although I have gotten it to barely
> work before. The question now becomes, how do I turn the mike on?
> 
> Also, the -D parameter uses the PCM, which is what the -L gives -- not
> that I know which of those numbers *is* a PCM.
> 

excuse me but you are not correct

use amixer

amixer | grep Input
Simple mixer control 'Digital Input Source',0
  Items: 'Analog Inputs' 'Digital Mic 1' 'Digital Mic 2' 'CD'
  Item0: 'Analog Inputs'
Simple mixer control 'Digital Input Source',1
  Items: 'Analog Inputs' 'Digital Mic 1' 'Digital Mic 2' 'CD'
  Item0: 'Analog Inputs'

and use alsamixer or similar to turn your mic on

If your driver is not properly configured you can have some options mixed up
so play around

I'm personally using following to test input

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

Recording WAVE '/dev/null' : Signed 16 bit Little Endian, Rate 44100 Hz,
Stereo
Plug PCM: Route conversion PCM (sformat=S16_LE)
  Transformation table:
    0 <- 0
    1 <- 0
Its setup is:
  stream       : CAPTURE
  access       : RW_INTERLEAVED
  format       : S16_LE
  subformat    : STD
  channels     : 2
  rate         : 44100
  exact rate   : 44100 (44100/1)
  msbits       : 16
  buffer_size  : 22050
  period_size  : 5513
  period_time  : 125011
  tstamp_mode  : NONE
  period_step  : 1
  avail_min    : 5513
  period_event : 0
  start_threshold  : 1
  stop_threshold   : 22050
  silence_threshold: 0
  silence_size : 0
  boundary     : 1445068800
Slave: Hardware PCM card 2 'Philips SPC 1000NC Webcam' device 0 subdevice 0
Its setup is:
  stream       : CAPTURE
  access       : MMAP_INTERLEAVED
  format       : S16_LE
  subformat    : STD
  channels     : 1
  rate         : 44100
  exact rate   : 44100 (44100/1)
  msbits       : 16
  buffer_size  : 22050
  period_size  : 5513
  period_time  : 125011
  tstamp_mode  : NONE
  period_step  : 1
  avail_min    : 5513
  period_event : 0
  start_threshold  : 1
  stop_threshold   : 22050
  silence_threshold: 0
  silence_size : 0
  boundary     : 1445068800
###   +                                            | 10%^C
Aborted by signal Interrupt...

regards


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