在 Python 中读取和/或更改 Windows 8 主卷 [重复]
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【中文标题】在 Python 中读取和/或更改 Windows 8 主卷 [重复]【英文标题】:Read and/or Change Windows 8 Master Volume in Python [duplicate] 【发布时间】:2015-08-21 21:54:44 【问题描述】:如何使用 python 更改笔记本电脑的主音量?我知道一种方法,我使用 ctypes 模拟音量增大/音量减小按键,但是在不知道当前音量的情况下,每当我启动应用程序进行校准时,我必须让我的代码执行 50 次连续的音量减小按键归零。
有没有办法让我获得当前的系统音量,或者更好的是,将主音量设置为指定值?
我正在使用 Python 3.4 运行 Windows 8 64 位系统。
【问题讨论】:
请问您的申请是什么? Python 的内置音频能力很差。 从 Python 中调用类似于 mixerOpen 的 Windows API。 @DavidChing,在 Vista 和更高版本中,winmm.dll API 修改了每个应用程序的音频设置。设置主音量需要使用IAudioEndpointVolume
COM 接口。
谢谢@eryksun,我不知道!
【参考方案1】:
Tim Roberts 在 python-win32 讨论列表中发布了一个 comtypes 示例,说明如何使用 Control Volume on Windows。在下面的示例中,我修改了 Tim 的代码并添加了返回默认音频端点及其 IAudioEndpointVolume
接口的类方法。
我测试的两个系统(Windows 7 和 Windows 10)上的 dB 音量范围将最大音量标准化为 0 dB,但最小音量和音量增量因系统而异。我建议改用标量和积分步长方法。标量范围是 0.0 到 1.0。
import ctypes
import comtypes
from ctypes import wintypes
MMDeviceApiLib = comtypes.GUID(
'2FDAAFA3-7523-4F66-9957-9D5E7FE698F6')
IID_IMMDevice = comtypes.GUID(
'D666063F-1587-4E43-81F1-B948E807363F')
IID_IMMDeviceCollection = comtypes.GUID(
'0BD7A1BE-7A1A-44DB-8397-CC5392387B5E')
IID_IMMDeviceEnumerator = comtypes.GUID(
'A95664D2-9614-4F35-A746-DE8DB63617E6')
IID_IAudioEndpointVolume = comtypes.GUID(
'5CDF2C82-841E-4546-9722-0CF74078229A')
CLSID_MMDeviceEnumerator = comtypes.GUID(
'BCDE0395-E52F-467C-8E3D-C4579291692E')
# EDataFlow
eRender = 0 # audio rendering stream
eCapture = 1 # audio capture stream
eAll = 2 # audio rendering or capture stream
# ERole
eConsole = 0 # games, system sounds, and voice commands
eMultimedia = 1 # music, movies, narration
eCommunications = 2 # voice communications
LPCGUID = REFIID = ctypes.POINTER(comtypes.GUID)
LPFLOAT = ctypes.POINTER(ctypes.c_float)
LPDWORD = ctypes.POINTER(wintypes.DWORD)
LPUINT = ctypes.POINTER(wintypes.UINT)
LPBOOL = ctypes.POINTER(wintypes.BOOL)
PIUnknown = ctypes.POINTER(comtypes.IUnknown)
class IMMDevice(comtypes.IUnknown):
_iid_ = IID_IMMDevice
_methods_ = (
comtypes.COMMETHOD([], ctypes.HRESULT, 'Activate',
(['in'], REFIID, 'iid'),
(['in'], wintypes.DWORD, 'dwClsCtx'),
(['in'], LPDWORD, 'pActivationParams', None),
(['out','retval'], ctypes.POINTER(PIUnknown), 'ppInterface')),
comtypes.STDMETHOD(ctypes.HRESULT, 'OpenPropertyStore', []),
comtypes.STDMETHOD(ctypes.HRESULT, 'GetId', []),
comtypes.STDMETHOD(ctypes.HRESULT, 'GetState', []))
PIMMDevice = ctypes.POINTER(IMMDevice)
class IMMDeviceCollection(comtypes.IUnknown):
_iid_ = IID_IMMDeviceCollection
PIMMDeviceCollection = ctypes.POINTER(IMMDeviceCollection)
class IMMDeviceEnumerator(comtypes.IUnknown):
_iid_ = IID_IMMDeviceEnumerator
_methods_ = (
comtypes.COMMETHOD([], ctypes.HRESULT, 'EnumAudioEndpoints',
(['in'], wintypes.DWORD, 'dataFlow'),
(['in'], wintypes.DWORD, 'dwStateMask'),
(['out','retval'], ctypes.POINTER(PIMMDeviceCollection),
'ppDevices')),
comtypes.COMMETHOD([], ctypes.HRESULT, 'GetDefaultAudioEndpoint',
(['in'], wintypes.DWORD, 'dataFlow'),
(['in'], wintypes.DWORD, 'role'),
(['out','retval'], ctypes.POINTER(PIMMDevice), 'ppDevices')))
@classmethod
def get_default(cls, dataFlow, role):
enumerator = comtypes.CoCreateInstance(
CLSID_MMDeviceEnumerator, cls, comtypes.CLSCTX_INPROC_SERVER)
return enumerator.GetDefaultAudioEndpoint(dataFlow, role)
class IAudioEndpointVolume(comtypes.IUnknown):
_iid_ = IID_IAudioEndpointVolume
_methods_ = (
comtypes.STDMETHOD(ctypes.HRESULT, 'RegisterControlChangeNotify', []),
comtypes.STDMETHOD(ctypes.HRESULT, 'UnregisterControlChangeNotify', []),
comtypes.COMMETHOD([], ctypes.HRESULT, 'GetChannelCount',
(['out', 'retval'], LPUINT, 'pnChannelCount')),
comtypes.COMMETHOD([], ctypes.HRESULT, 'SetMasterVolumeLevel',
(['in'], ctypes.c_float, 'fLevelDB'),
(['in'], LPCGUID, 'pguidEventContext', None)),
comtypes.COMMETHOD([], ctypes.HRESULT, 'SetMasterVolumeLevelScalar',
(['in'], ctypes.c_float, 'fLevel'),
(['in'], LPCGUID, 'pguidEventContext', None)),
comtypes.COMMETHOD([], ctypes.HRESULT, 'GetMasterVolumeLevel',
(['out','retval'], LPFLOAT, 'pfLevelDB')),
comtypes.COMMETHOD([], ctypes.HRESULT, 'GetMasterVolumeLevelScalar',
(['out','retval'], LPFLOAT, 'pfLevel')),
comtypes.COMMETHOD([], ctypes.HRESULT, 'SetChannelVolumeLevel',
(['in'], wintypes.UINT, 'nChannel'),
(['in'], ctypes.c_float, 'fLevelDB'),
(['in'], LPCGUID, 'pguidEventContext', None)),
comtypes.COMMETHOD([], ctypes.HRESULT, 'SetChannelVolumeLevelScalar',
(['in'], wintypes.UINT, 'nChannel'),
(['in'], ctypes.c_float, 'fLevel'),
(['in'], LPCGUID, 'pguidEventContext', None)),
comtypes.COMMETHOD([], ctypes.HRESULT, 'GetChannelVolumeLevel',
(['in'], wintypes.UINT, 'nChannel'),
(['out','retval'], LPFLOAT, 'pfLevelDB')),
comtypes.COMMETHOD([], ctypes.HRESULT, 'GetChannelVolumeLevelScalar',
(['in'], wintypes.UINT, 'nChannel'),
(['out','retval'], LPFLOAT, 'pfLevel')),
comtypes.COMMETHOD([], ctypes.HRESULT, 'SetMute',
(['in'], wintypes.BOOL, 'bMute'),
(['in'], LPCGUID, 'pguidEventContext', None)),
comtypes.COMMETHOD([], ctypes.HRESULT, 'GetMute',
(['out','retval'], LPBOOL, 'pbMute')),
comtypes.COMMETHOD([], ctypes.HRESULT, 'GetVolumeStepInfo',
(['out','retval'], LPUINT, 'pnStep'),
(['out','retval'], LPUINT, 'pnStepCount')),
comtypes.COMMETHOD([], ctypes.HRESULT, 'VolumeStepUp',
(['in'], LPCGUID, 'pguidEventContext', None)),
comtypes.COMMETHOD([], ctypes.HRESULT, 'VolumeStepDown',
(['in'], LPCGUID, 'pguidEventContext', None)),
comtypes.COMMETHOD([], ctypes.HRESULT, 'QueryHardwareSupport',
(['out','retval'], LPDWORD, 'pdwHardwareSupportMask')),
comtypes.COMMETHOD([], ctypes.HRESULT, 'GetVolumeRange',
(['out','retval'], LPFLOAT, 'pfLevelMinDB'),
(['out','retval'], LPFLOAT, 'pfLevelMaxDB'),
(['out','retval'], LPFLOAT, 'pfVolumeIncrementDB')))
@classmethod
def get_default(cls):
endpoint = IMMDeviceEnumerator.get_default(eRender, eMultimedia)
interface = endpoint.Activate(cls._iid_, comtypes.CLSCTX_INPROC_SERVER)
return ctypes.cast(interface, ctypes.POINTER(cls))
例如:
if __name__ == '__main__':
def show_vol(ev):
voldb = ev.GetMasterVolumeLevel()
volsc = ev.GetMasterVolumeLevelScalar()
volst, nstep = ev.GetVolumeStepInfo()
print('Master Volume (dB): %0.4f' % voldb)
print('Master Volume (scalar): %0.4f' % volsc)
print('Master Volume (step): %d / %d' % (volst, nstep))
def test():
ev = IAudioEndpointVolume.get_default()
vol = ev.GetMasterVolumeLevelScalar()
vmin, vmax, vinc = ev.GetVolumeRange()
print('Volume Range (min, max, step) (dB): '
'%0.4f, %0.4f, %0.4f' % (vmin, vmax, vinc))
show_vol(ev)
try:
print('\nIncrement the master volume')
ev.VolumeStepUp()
show_vol(ev)
print('\nDecrement the master volume twice')
ev.VolumeStepDown()
ev.VolumeStepDown()
show_vol(ev)
print('\nSet the master volume to 0.75 scalar')
ev.SetMasterVolumeLevelScalar(0.75)
show_vol(ev)
print('\nSet the master volume to 0.25 scalar')
ev.SetMasterVolumeLevelScalar(0.25)
show_vol(ev)
finally:
ev.SetMasterVolumeLevelScalar(vol)
comtypes.CoInitialize()
try:
test()
finally:
comtypes.CoUninitialize()
【讨论】:
谢谢!效果很好!以上是关于在 Python 中读取和/或更改 Windows 8 主卷 [重复]的主要内容,如果未能解决你的问题,请参考以下文章
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