Get default audio/video device

Question

I am using dotNet c# . I need to identify default video and audio device I do know that I can enumerate audio device but how to determine default one ? ManagementObjectSearc

Answer 1

Thanks to the hard work by @Exergist, and some reading of the code, I acheived the same result in Python so that I can use pyaudio properly. Also, I had to use Level:0 not Role:0. Here is my final result

import winreg as wr
import platform


def is_os_64bit():
    return platform.machine().endswith('64')


def get_active_device():
    read_access = wr.KEY_READ | wr.KEY_WOW64_64KEY if is_os_64bit() else wr.KEY_READ
    audio_path = r'SOFTWARE\Microsoft\Windows\CurrentVersion\MMDevices\Audio\Render'
    child_key = wr.OpenKeyEx(wr.HKEY_LOCAL_MACHINE, audio_path, 0, read_access)
    devices = wr.QueryInfoKey(child_key)[0]
    active_last_used = -1
    active_device_name = None
    for i in range(devices):
        device_key_path = f'{audio_path}\\{wr.EnumKey(child_key, i)}'
        device_key = wr.OpenKeyEx(wr.HKEY_LOCAL_MACHINE, device_key_path, 0, read_access)
        if wr.QueryValueEx(device_key, 'DeviceState')[0] == 1:
            properties_path = f'{device_key_path}\\Properties'
            properties = wr.OpenKeyEx(wr.HKEY_LOCAL_MACHINE, properties_path, 0, read_access)
            device_name = wr.QueryValueEx(properties, '{b3f8fa53-0004-438e-9003-51a46e139bfc},6')[0]
            device_type = wr.QueryValueEx(properties, '{a45c254e-df1c-4efd-8020-67d146a850e0},2')[0]
            pa_name = f'{device_type} ({device_name})'  # name shown in PyAudio
            last_used = wr.QueryValueEx(device_key, 'Level:0')[0]
            if last_used > active_last_used:  # the bigger the number, the more recent it was used
                active_last_used = last_used
                active_device_name = pa_name
    return active_device_name