How to specify a device from a query?

[ullix]

On my Ubuntu 16.04 computer a call to sd.query_devices() gives this answer (some lines removed):

4 HDA Intel PCH: ALC887-VD Analog (hw:1,0), ALSA (2 in, 8 out)
5 HDA Intel PCH: ALC887-VD Digital (hw:1,1), ALSA (0 in, 2 out)
6 HDA Intel PCH: ALC887-VD Alt Analog (hw:1,2), ALSA (2 in, 0 out)
*9 default, ALSA (32 in, 32 out)

When I then call the # 4 device by print(sd.query_devices(device="HDA Intel PCH: ALC887-VD Analog", kind= 'input')) I get an exception:

ValueError: Multiple input devices found for 'HDA Intel PCH: ALC887-VD Analog':
[4] HDA Intel PCH: ALC887-VD Analog (hw:1,0), ALSA
[6] HDA Intel PCH: ALC887-VD Alt Analog (hw:1,2), ALSA

So how can I then select # 4 when this cannot be distinguished from # 6, although the 'Alt' word is missing in the query?

Selecting # 6 with device="HDA Intel PCH: ALC887-VD Alt Analog" does work. Once this is done, I can call the non-Alt # 4 device, and not have an exception, but: this works because the command automatically calls the # 6 device, and not # 4!

So, no way to select # 4. What else can I provide when using the default names?

[mgeier]

The string is not compared "exactly", see https://python-sounddevice.readthedocs.io/en/0.4.0/api/module-defaults.html#sounddevice.default.device:

If a string is given, the device is selected which contains all space-separated parts in the right order. Each device string contains the name of the corresponding host API in the end. The string comparison is case-insensitive.

In your case, you should be able to use device='hw:1,0' or device=4.

[raveslave]

how about adding / exposing the serial-number from the raw usb descriptor itself?

this way each sound-card would have a unique handle that can also be used to create a more flexible connectionID that doesn't shift (when things are hotplugged) as with an index based setup.

[mgeier]

@raveslave

how about adding / exposing the serial-number from the raw usb descriptor itself?

this way each sound-card would have a unique handle that can also be used to create a more flexible connectionID that doesn't shift (when things are hotplugged) as with an index based setup.

This is something that can only be done in the underlying PortAudio library, you should ask at their issue tracker: https://github.com/PortAudio/portaudio/issues

[raveslave]

done: PortAudio/portaudio#11