精确控制windows全局音量二（Python）

from comtypes import *


class IAudioEndpointVolume(IUnknown):
    _iid_ = GUID('{5CDF2C82-841E-4546-9722-0CF74078229A}')
    _methods_ = [
        COMMETHOD([], HRESULT, 'RegisterControlChangeNotify',
                  (['in'], c_voidp, 'pNotify')
                  ),
        COMMETHOD([], HRESULT, 'UnregisterControlChangeNotify',
                  (['in'], c_voidp, 'pNotify')
                  ),
        COMMETHOD([], HRESULT, 'GetChannelCount',
                  (['out'], POINTER(c_uint), 'pnChannelCount')
                  ),
        COMMETHOD([], HRESULT, 'SetMasterVolumeLevel',
                  (['in'], c_float, 'fLevelDB'),
                  (['in'], c_voidp, 'pguidEventContext')
                  ),
        COMMETHOD([], HRESULT, 'SetMasterVolumeLevelScalar',
                  (['in'], c_float, 'fLevel'),
                  (['in'], c_voidp, 'pguidEventContext')
                  ),
        COMMETHOD([], HRESULT, 'GetMasterVolumeLevel',
                  (['out'], POINTER(c_float), 'pfLevelDB')
                  ),
        COMMETHOD([], HRESULT, 'GetMasterVolumeLevelScalar',
                  (['out'], POINTER(c_float), 'pfLevel')
                  ),
        COMMETHOD([], HRESULT, 'SetChannelVolumeLevel',
                  (['in'], c_uint, 'nChannel'),
                  (['in'], c_float, 'fLevelDB'),
                  (['in'], c_voidp, 'pguidEventContext')
                  ),
        COMMETHOD([], HRESULT, 'SetChannelVolumeLevelScalar',
                  (['in'], c_uint, 'nChannel'),
                  (['in'], c_float, 'fLevel'),
                  (['in'], c_voidp, 'pguidEventContext')
                  ),
        COMMETHOD([], HRESULT, 'GetChannelVolumeLevel',
                  (['in'], c_uint, 'nChannel'),
                  (['out'], POINTER(c_float), 'pfLevelDB')
                  ),
        COMMETHOD([], HRESULT, 'GetChannelVolumeLevelScalar',
                  (['in'], c_uint, 'nChannel'),
                  (['out'], POINTER(c_float), 'pfLevel')
                  ),
        COMMETHOD([], HRESULT, 'SetMute',
                  (['in'], c_int, 'bMute'),
                  (['in'], c_voidp, 'pguidEventContext')
                  ),
        COMMETHOD([], HRESULT, 'GetMute',
                  (['out'], POINTER(c_bool), 'pbMute')
                  ),
        COMMETHOD([], HRESULT, 'GetVolumeStepInfo',
                  (['out'], POINTER(c_uint), 'pnStep'),
                  (['out'], POINTER(c_uint), 'pnStepCount')
                  ),
        COMMETHOD([], HRESULT, 'VolumeStepUp',
                  (['in'], c_voidp, 'pguidEventContext')
                  ),
        COMMETHOD([], HRESULT, 'VolumeStepDown',
                  (['in'], c_voidp, 'pguidEventContext')
                  ),
        COMMETHOD([], HRESULT, 'QueryHardwareSupport',
                  (['out'], POINTER(c_uint), 'pdwHardwareSupportMask')
                  ),
        COMMETHOD([], HRESULT, 'GetVolumeRange',
                  (['out'], POINTER(c_float), 'pflVolumeMindB'),
                  (['out'], POINTER(c_float), 'pflVolumeMaxdB'),
                  (['out'], POINTER(c_float), 'pflVolumeIncrementdB')
                  )
    ]


class IMMDevice(IUnknown):
    _iid_ = GUID('{D666063F-1587-4E43-81F1-B948E807363F}')
    _methods_ = [
        COMMETHOD([], HRESULT, 'Activate',
                  (['in'], POINTER(GUID), 'iid'),
                  (['in'], c_uint, 'dwClsCtx'),
                  (['in'], c_voidp, 'pActivationParams'),
                  (['out'], POINTER(POINTER(IAudioEndpointVolume)), 'ppInterface')
                  ),
        COMMETHOD([], HRESULT, 'OpenPropertyStore',
                  (['in'], c_int32, 'stgmAccess'),
                  (['out'], c_voidp, 'ppProperties')
                  ),
        COMMETHOD([], HRESULT, 'GetId',
                  (['out'], c_voidp, 'ppstrId')
                  ),
        COMMETHOD([], HRESULT, 'GetState',
                  (['out'], POINTER(c_uint), 'pdwState')
                  )
    ]


class IMMDeviceEnumerator(IUnknown):
    _iid_ = GUID('{A95664D2-9614-4F35-A746-DE8DB63617E6}')
    _methods_ = [
        COMMETHOD([], HRESULT, 'EnumAudioEndpoints',
                  (['in'], c_int, 'dataFlow'),
                  (['in'], c_int, 'dwStateMask'),
                  (['out'], POINTER(c_voidp), 'ppDevices')
                  ),
        COMMETHOD([], HRESULT, 'GetDefaultAudioEndpoint',
                  (['in'], c_int, 'dataFlow'),
                  (['in'], c_int, 'role'),
                  (['out'], POINTER(POINTER(IMMDevice)))
                  ),
        COMMETHOD([], HRESULT, 'GetDevice',
                  (['in'], c_voidp, 'pwstrId'),
                  (['out'], POINTER(POINTER(IMMDevice)))
                  ),
        COMMETHOD([], HRESULT, 'RegisterEndpointNotificationCallback',
                  (['in'], c_voidp)
                  ),
        COMMETHOD([], HRESULT, 'UnregisterEndpointNotificationCallback',
                  (['in'], c_voidp)
                  )
    ]


class VolCtrl(object):
    def __init__(self):
        clsid = GUID('{BCDE0395-E52F-467C-8E3D-C4579291692E}')
        pMde = CoCreateInstance(clsid, interface=IMMDeviceEnumerator)

        EDataFlow_eRender = 0
        ERole_eConsole = 0

        pDevice = pMde.GetDefaultAudioEndpoint(EDataFlow_eRender, ERole_eConsole)

        CLSCTX_ALL = 0x17

        iid = GUID('{5CDF2C82-841E-4546-9722-0CF74078229A}')
        pEndPoint = pDevice.Activate(byref(iid), CLSCTX_ALL, None)
        self.__pEndPoint = pEndPoint

    def mastervol_up(self):
        self.__pEndPoint.VolumeStepUp(None)

    def mastervol_down(self):
        self.__pEndPoint.VolumeStepDown(None)

    @property
    def mastervol(self):
        return self.__pEndPoint.GetMasterVolumeLevelScalar()

    @mastervol.setter
    def mastervol(self, vol):
        print
        vol
        self.__pEndPoint.SetMasterVolumeLevelScalar(vol, None)

class vol_helper:
    def __init__(self):
        self.vc = VolCtrl()
    def get_vol(self):
        # print('获取音量')
        # ev = IAudioEndpointVolume.get_default()
        return round(self.vc.mastervol, 2)
    def set_vol(self,vol):
        # print('设置音量')
        if vol >= 0 and vol <=1:
            # ev = IAudioEndpointVolume.get_default()
            # ev.SetMasterVolumeLevelScalar(vol)
            self.vc.mastervol = vol