Re: [Discuss-gnuradio] How to specify Audio Source device_name?

[Cinaed Simson]

On 09/22/2016 12:06 PM, Paul Zander wrote:
> Problem solved.  I used the Sound GUI under the Settingsmenu to select
> the audio source.  
> I am not sure if that is PulseAudio, but the selections and gain
> settings do work.
> 
> I even found that I could switch the device while the flowgraph was running.
> 
> That said, I am puzzled about the intended usage of HW:1,0 and and
> similar device names.
> Suppose I create |~/.asoundrc |following the instructions at:
>   http://gnuradio.org/redmine/projects/gnuradio/wiki/ALSAPulseAudio
> |
> |
> |Then should I be able to specify the device name in GRC
> |
> |and not have to rely on the audio setings?
> |
> 

Under Debian, the pulseaudio server is started in the daemon mode on
system startup - it takes control of all audio devices.

If you're running Ubuntu which is a fork of Debian, it should behave in
a manner, i.e., you have to use pulseaudio to use alsa device drivers.

I presume the syntax hw:1,0 is for alsa - although I've never seen it
displayed by aplay/arecord - but then I've always used pulseaudio.

And yes, under Find PulseAudio monitors

 http://gnuradio.org/redmine/projects/gnuradio/wiki/ALSAPulseAudio

should work as long as there is alsa monitor entry for the USB device.

I've never tried it.

-- Cinaed

> 
> On 09/21/2016 12:40 PM,Cinaed Simson wrote:
>>
>> On 09/21/2016 09:40 AM, Paul Zander wrote:
>>> Cinaed,
>>>
>>> Your suggestion about testing the audio suggested an new experiment that
>>> may be a work-around.
>>>
>>> With Settings >> Sound >> Input >> Internal Microphone,  my GRC with (QT
>>> GUI Time Sink) shows a signal that responds to the internal microphone.
>>> Speaking or clapping hands causes a response on the graph.
>>>
>>> When I change the Input to Microphone, USB Audio Device, and re-execute
>>> the flowgraph,  the signal is very small and does not respond to
>>> sounds.  Maybe Audio Source only works with the default input from the
>>> system.
>>
>> Use the PulseAudio Volume control to turn up the volume on the input
>> device. You can find the find the input device under Inputs.