Changing the volume of a non-default sound device

[ghost]

I always used SetMasterVolumeLevel to change the volume level on my pc, but now I have a problem because I need to change the volume of a different sound device. Is there a way to solve this?

[ahartquist]

I would like to control volume of an app, but I don't know how to do it if the app is on a non default device.
I have found that when I try to report all process names with AudioUtilities.GetAllSessions(), I only obtain a list of the applications that are associated with the default device.

This appears to be due to GetAllSessions() relies on
GetAudioSessionManager() which relies on
GetSpeakers() which relies on
GetDefaultAudioEndpoint. <---- That's the problem, it only takes into account the default audio endpoint (default device).

Anyone know a way around this?

from pycaw.pycaw import AudioUtilities, IAudioEndpointVolume

print("\nAll Auido Device Sessions: ")
AllSessions = AudioUtilities.GetAllSessions()
for d in AllSessions:
  print(d.Process.name())

[Morph763]

Anyone having an answer to the above?

What i can tell is that within the GetSpeakers() function the above is pointing to GetDefaultAudioEndpoint

speakers = deviceEnumerator.GetDefaultAudioEndpoint( EDataFlow.eRender.value, ERole.eMultimedia.value)

within the GetAllDevices funtion i am able to list sound output devices but the same data are not being collected.

collection = deviceEnumerator.EnumAudioEndpoints( EDataFlow.eAll.value, DEVICE_STATE.MASK_ALL.value)

Knowing this is looks like it could be possible to fetch the same values for output devices not considered "default" but not sure how that would be done.

[akaufman1]

I sub-classed the AudioUtilities class and overrode the Get Speaker function to allow input of device id gathered from the GetAllDevices method.

class MyAudioUtilities(AudioUtilities):

    @staticmethod
    def GetSpeaker(id=None):

        device_enumerator = comtypes.CoCreateInstance(
            CLSID_MMDeviceEnumerator,
            IMMDeviceEnumerator,
            comtypes.CLSCTX_INPROC_SERVER)
        if id is not None:
            speakers = device_enumerator.GetDevice(id)
        else:
            speakers = device_enumerator.GetDefaultAudioEndpoint(EDataFlow.eRender.value, ERole.eMultimedia.value)
        return speakers

I edited the endpoint example as such (including the new class):

from __future__ import print_function
from ctypes import POINTER, cast
import comtypes
from comtypes import CLSCTX_ALL

from pycaw.pycaw import AudioUtilities, IAudioEndpointVolume, CLSID_MMDeviceEnumerator, IMMDeviceEnumerator, EDataFlow, ERole


class MyAudioUtilities(AudioUtilities):
    @staticmethod
    def GetSpeaker(id=None):
        device_enumerator = comtypes.CoCreateInstance(
            CLSID_MMDeviceEnumerator,
            IMMDeviceEnumerator,
            comtypes.CLSCTX_INPROC_SERVER)
        if id is not None:
            speakers = device_enumerator.GetDevice(id)
        else:
            speakers = device_enumerator.GetDefaultAudioEndpoint(EDataFlow.eRender.value, ERole.eMultimedia.value)
        return speakers


def main():
    mixer_output = None

    devicelist = MyAudioUtilities.GetAllDevices()

    for device in devicelist:
        if "UMC404HD" in str(device) and "Speaker" in str(device):
            mixer_output = device

    devices = MyAudioUtilities.GetSpeaker(mixer_output.id)
    print(devices)

    interface = devices.Activate(
        IAudioEndpointVolume._iid_, CLSCTX_ALL, None)
    volume = cast(interface, POINTER(IAudioEndpointVolume))
    print("volume.GetMute(): %s" % volume.GetMute())
    print("volume.GetMasterVolumeLevel(): %s" % volume.GetMasterVolumeLevel())
    print("volume.GetVolumeRange(): (%s, %s, %s)" % volume.GetVolumeRange())
    print("volume.SetMasterVolumeLevel()")
    volume.SetMasterVolumeLevel(-20.0, None)
    print("volume.GetMasterVolumeLevel(): %s" % volume.GetMasterVolumeLevel())


if __name__ == "__main__":
    main()

[Morph763]

Thanks @akaufman1 for helping us with this. I have not been able to try it yet but sure will!