如何在Python中初始化XAudio2（CreateMasteringVoice错误）？

Question

我正在尝试在Win10下使用XAudio2制作音乐播放器，这是当前代码：

from ctypes import Structure, POINTER, windll, byref, memset, sizeof, pointer, wintypes
from ctypes import c_void_p, c_uint, c_char, c_long
from ctypes.wintypes import DWORD, WORD, BYTE

XAUDIO2_DEFAULT_PROCESSOR = 1

def init():

    class XAUDIO2_EFFECT_DESCRIPTOR(Structure):
        _fields_ = (    ( 'pEffect', c_void_p),
                        ( 'InitialState', BYTE),
                        ( 'OutputChannels', DWORD) )

    class XAUDIO2_EFFECT_CHAIN(Structure):
        _fields_ = (    ( 'EffectCount', DWORD),
                        ( 'pEffectDescriptors', POINTER(XAUDIO2_EFFECT_DESCRIPTOR) ) )

    lib = windll.LoadLibrary('XAudio2_9.dll')
    print(lib)
    func = lib['XAudio2Create']
    print(func)
    ppXAudio2 = c_void_p()
    print(ppXAudio2)  
    res = lib.XAudio2Create(byref(ppXAudio2), 0, XAUDIO2_DEFAULT_PROCESSOR)
    if res:
        print("XAudio2Create err: ", res)
        return
    else:
        print(ppXAudio2)    
    ppMasteringVoice = c_void_p()
    InputChannels = 2
    InputSampleRate = 44100
    effect = XAUDIO2_EFFECT_DESCRIPTOR()
    memset(byref(effect),0,sizeof(effect))
    effect.pEffect = c_void_p()
    effect.InitialState = 0
    effect.OutputChannels = 1
    pEffectChain = XAUDIO2_EFFECT_CHAIN()
    memset(byref(pEffectChain),0,sizeof(pEffectChain))
    pEffectChain.EffectCount = 0
    pEffectChain.pEffectDescriptors = pointer(effect)

    res = ppXAudio2.CreateMasteringVoice( byref(ppMasteringVoice), InputChannels, InputSampleRate,
                                    0, 0, byref(pEffectChain), 0 )   

下面是我得到的输出，我想我需要将ppXAudio2转换为XAudio2实例的类型，但是我不确定如何：

WinDLL'XAudio2_9.dll'，在0x224b7068160处处理7fffcc620000

_FuncPtr对象位于0x00000224B5150C78

c_void_p（无）

c_void_p（2356714864784）

AttributeError：'c_void_p'对象没有属性'CreateMasteringVoice'