Error from PortAudio unless permission for microphone access given in Windows settings

[ileben]

I am running Microsoft Windows 10 Enterprise 10.0.18363 Build 18363. If I don't manually give microphone permission in Windows settings, sounddevice crashes with an error from PortAudio with a confusing error (below). I was attempting to run Caster voice recognition using kaldi-active-grammar 1.8.1. It seems like one of these (perhaps sounddevice?) should ask or at least check for microphone permissions and provide a better error message to the user with instructions on what to do.

Traceback (most recent call last):
  File "C:\Python27-64bit\lib\runpy.py", line 174, in _run_module_as_main
    "__main__", fname, loader, pkg_name)
  File "C:\Python27-64bit\lib\runpy.py", line 72, in _run_code
    exec code in run_globals
  File "C:\Python27-64bit\lib\site-packages\dragonfly\__main__.py", line 408, in <module>
    main()
  File "C:\Python27-64bit\lib\site-packages\dragonfly\__main__.py", line 403, in main
    return_code = func(args)
  File "C:\Python27-64bit\lib\site-packages\dragonfly\__main__.py", line 174, in cli_cmd_load
    with engine.connection():
  File "C:\Python27-64bit\lib\site-packages\dragonfly\engines\base\engine.py", line 50, in __enter__
    self._engine.connect()
  File "C:\Python27-64bit\lib\site-packages\dragonfly\engines\backend_kaldi\engine.py", line 197, in connect
    reconnect_callback=self._options['audio_reconnect_callback'],
  File "C:\Python27-64bit\lib\site-packages\dragonfly\engines\backend_kaldi\audio.py", line 228, in __init__
    super(VADAudio, self).__init__(**kwargs)
  File "C:\Python27-64bit\lib\site-packages\dragonfly\engines\backend_kaldi\audio.py", line 75, in __init__
    self._connect(start=start)
  File "C:\Python27-64bit\lib\site-packages\dragonfly\engines\backend_kaldi\audio.py", line 89, in _connect
    callback=proxy_callback if not self.self_threaded else None,
  File "C:\Python27-64bit\lib\site-packages\sounddevice.py", line 1153, in __init__
    **_remove_self(locals()))
  File "C:\Python27-64bit\lib\site-packages\sounddevice.py", line 861, in __init__
    'Error opening {0}'.format(self.__class__.__name__))
  File "C:\Python27-64bit\lib\site-packages\sounddevice.py", line 2651, in _check
    raise PortAudioError(errormsg, err, hosterror_info)
sounddevice.PortAudioError: Error opening RawInputStream: Unanticipated host error [PaErrorCode -9999]: 'Undefined external error.' [MME error 1]

[mgeier]

Thanks for the report.

The confusing error (Undefined external error) comes from PortAudio. I think it would be best to report the issue to their issue tracker: https://github.com/PortAudio/portaudio

Once they produce a better error, it will automatically be used in the sounddevice module as well.