Multiple Sound Card Wizard query....

[mikewalsh]

Afternoon, guys'n'gals.

Now then; Uncle Mike has a query about sound "stuff". Need some advice, please.

I have a Logitech c920 HD "Pro" USB webcam. Various things will, when requested, allow me to select this as the default sound card to use, specifically for its microphone. I have noticed, however, that it never shows up in the 'Multiple Sound Cards' section of the ALSA Sound Wizard.

Am I correct in thinking that this is because it doesn't have an 'output' side? Like all webcams, it has a microphone, but of course, no speakers.

I'm playing around with various speech recognition items in Chrome. Chrome (or Iron, my 'fave' Chrome alternative) under Linux doesn't present me with a microphone 'drop-down' selector box in the Settings section.....although curiously, when setting things up in the Google "Duo" video chat app, it will allow you to select the webcam as microphone source, despite not showing up in the ALSA Sound Wizard.....

See why I'm getting confused, kids?

Code: Select all

arecord -l

.....quite happily detects it:-

Code: Select all

# arecord -l
**** List of CAPTURE Hardware Devices ****
card 0: Intel [HDA Intel], device 0: ALC671 Analog [ALC671 Analog]
  Subdevices: 1/1
  Subdevice #0: subdevice #0
card 0: Intel [HDA Intel], device 2: ALC671 Alt Analog [ALC671 Alt Analog]
  Subdevices: 1/1
  Subdevice #0: subdevice #0
card 3: C920 [HD Pro Webcam C920], device 0: USB Audio [USB Audio]
  Subdevices: 1/1
  Subdevice #0: subdevice #0
#

.....but it doesn't show up in the Multiple Sound Card thingy:-

[Click to enlarge:-]





All I get there is the built-in soundcad, and the Nvidia graphics card (I know these have a selectable audio output - probably multiple ones! - but I have no interest in those.)

So, I guess my query is this:

If the Multiple Sound Card selector doesn't detect it, is there an alternative way to select the webcam as "default" sound card? Google's "Duo" must be checking in a different place to the browser's settings dialog (which obviously checks the defaults, and sees that there's no microphone source, so, no drop-down selector - no point, right?) That's an educated guess, anyway.

Just so's y'all know, the c920 HD "Pro" is plugged-in permanently, so should, by rights, get detected.....yes? I've got ideas along the lines of a small script to "set" the webcam as default (temporarily) using the following:-

Code: Select all

# arecord -l | grep C920
card 3: C920 [HD Pro Webcam C920], device 0: USB Audio [USB Audio]
#

.....assigning it as a temporary variable, and setting it that way, but.....WHERE does Puppy store the default sound card info?

Any advice would be appreciated, boys & girls.


Mike.

[mikewalsh]

Now then:-

I've found a way round this wee conundrum... !!

I've been in jrb's "Lite" re-spin of Barry's Quirky64 April 7.0.1 all day. However, I know (from previous research) that this holds true for most modern Pups.

The Multiple Sound Card Wizard stores a text-file with the selected default card at /var/lib/mscw/selected. The problem, as stated above, is with the browser itself. I'm attempting to use the Google Voice Search feature, and a couple of rather neat voice-operated extensions for Chrome. However; because there's no drop-down selection box in the microphone settings, it doesn't even recognise the default card, never mind anything else.

Essentially, it's looking for an INPUT device, OK? By default, the built-in, Intel HD doesn't have one plugged-in. My two inputs are

- The Logitech webcam.....which is not "seen" by the Sound Card Wizard, and
- A Logitech H340 headset, which has its own, built-in card. This does get "seen" by the Sound Card Wizard..... when plugged-in, which isn't often. I mainly use this for video calls.

So; I wanted to make use of the webcam's stereo mikes, since that's there permanently. How to make it "active", and "seen" by the browser? It turned out to be quite easy, in fact...

--------------------------------------------------

The answer lies with that file I mentioned above, at /var/lib/mscw/selected. All I did was to run

Code: Select all

arecord -l | grep C920

....to bring up the webcam's card entry. I created another text file called "selected", pasted the output of the above command into it, and swapped it for the existing one. Shut Chrome down, re-started "X" just to be on the safe side, then fired Chrome up again.

This time, upon going into microphone settings, I now have the drop-down selection box showing, allowing me to actually select the webcam mikes as input (presumably because the browser is now able to detect an input source). Result?

Voice search in Google now WORKS. Yay!!

-----------------------------------------------

I'm no kind of an expert when it comes to Bash. A lot of it, to me, is just so much gibberish, though I am, slowly, getting the hang of simple scripting. I do see, however, that right at the top of the Multiple Sound card Wizard script, "var/lib/mscw" is prominently displayed as a line involving mkdir. I'd be curious to know quite how alsamixer interacts with all this, I'll be honest.

Anyways, to get round easy swapping back & forth between the webcam's soundcard & the Intel one, I've put a few wee scripts together along with modifying the GUI of one of my other utilities, like this:-





The two audio card buttons merely swap scripts over into /var/lib/mscw. I've created two sub-directories inside /var/lib/mscw, each with a dedicated copy of selected for the two sound cards. The bottom button simply opens /var/lib/mscw/selected with Geany, in case I can't remember which one is currently "loaded"....and with the way my memory is going these days, that may be rather more often than I'd care to admit.

Sorted..!


Mike.