Runtime error when attempting to initialize player in "exclusive_mode"

Hi,

I am attempting to generate real-time audio with low latency on a Windows 10 system with python 3.7. If I try to set the exclusive_mode argument to speaker.player() to True, mediafoundation.py throws an error at line 92: RuntimeError: invalid argument

Here is a snippet of code that generates the error for me:

speaker = soundcard.default_speaker()
with speaker.player(samplerate=48000, blocksize=1200, exclusive_mode=True) as audioplayer:
    pass

The values of samplerate and blocksize (and channels, which I left as default) do not seem to matter here, the error always happens when I set exclusive_mode=True.

Here is the full error when I run the above snippet in an interactive session:

Traceback (most recent call last):
  File "<stdin>", line 1, in <module>
  File "C:\Python\Anaconda3\lib\site-packages\soundcard\mediafoundation.py", line 435, in player
    return _Player(self._audio_client(), samplerate, channels, blocksize, False, exclusive_mode)
  File "C:\Python\Anaconda3\lib\site-packages\soundcard\mediafoundation.py", line 542, in __init__
    _com.check_error(hr)
  File "C:\Python\Anaconda3\lib\site-packages\soundcard\mediafoundation.py", line 92, in check_error
    raise RuntimeError("invalid argument")
RuntimeError: invalid argument

My PC has Realtek audio:

>>> print(speaker)
<Speaker Speakers (Realtek(R) Audio) (2 channels)>

Thanks! Overall this library seems very helpful and a bit easier to use than pyaudio.

[bastibe]

You can create the pull request at any time if you want to ask for help, just mark is as work-in-progress. I’m afraid I can’t help much at the moment, sorry.

[bastibe]

Brilliant! Thank you for investigating this!

So we might be restricted to a pre-set sample rate if we open a device in exclusive mode. Or perhaps we have to change the device’s sample rate, as opposed to the AudioClient’s.