Windows Media Foundation 枚举音频设备
Windows Media Foundation Enumerate audio devices
我使用了 Microsoft MSDN 提供的教程来枚举音频设备。
枚举代码如下:
HRESULT CreateAudioDeviceSource(IMFMediaSource **ppSource)
{
*ppSource = NULL;
IMFMediaSource *pSource = NULL;
IMFAttributes *pAttributes = NULL;
IMFActivate **ppDevices = NULL;
// Create an attribute store to specify the enumeration parameters.
HRESULT hr = MFCreateAttributes(&pAttributes, 1);
if (FAILED(hr))
{
goto done;
}
// Source type: audio capture devices
hr = pAttributes->SetGUID(
MF_DEVSOURCE_ATTRIBUTE_SOURCE_TYPE,
MF_DEVSOURCE_ATTRIBUTE_SOURCE_TYPE_AUDCAP_GUID
);
if (FAILED(hr))
{
goto done;
}
// Enumerate devices.
UINT32 count;
hr = MFEnumDeviceSources(pAttributes, &ppDevices, &count);
std::cout << count;
if (FAILED(hr))
{
std::cout << "Enum Failed";
goto done;
}
if (count == 0)
{
std::cout << "empty";
hr = E_FAIL;
goto done;
}
// Create the media source object.
hr = ppDevices[0]->ActivateObject(IID_PPV_ARGS(&pSource));
if (FAILED(hr))
{
goto done;
}
*ppSource = pSource;
(*ppSource)->AddRef();
done:
SafeRelease(&pAttributes);
for (DWORD i = 0; i < count; i++)
{
SafeRelease(&ppDevices[i]);
}
CoTaskMemFree(ppDevices);
SafeRelease(&pSource);
return hr;
}
但是我调用枚举设备的函数失败了。我收到消息 "Enum Failed"。所以我不知道为什么会出现这个问题。
拜托,非常感谢!
参考:https://msdn.microsoft.com/en-us/library/dd317912(v=vs.85).aspx
示例代码 Windows Media Foundation 枚举音频设备,设备捕获 struct
struct CaptureDeviceParam
{
/// <summary>
/// The array of devices.
/// </summary>
IMFActivate **ppDevices;
/// <summary>
/// Device count.
/// </summary>
UINT32 count;
/// <summary>
/// Device selection.
/// </summary>
UINT32 selection;
};
和enum
设备方法。
/// <summary>
/// Get the audio capture devices.
/// </summary>
/// <param name="param">The capture device param.</param>
void MediaCapture::GetAudioCaptureDevices(CaptureDeviceParam *param)
{
HRESULT hr = S_OK;
IMFAttributes *pAttributes = NULL;
// Initialize an attribute store to specify enumeration parameters.
hr = MFCreateAttributes(&pAttributes, 1);
// Ask for source type = audio capture devices
if (SUCCEEDED(hr))
{
// Set the device attribute.
hr = pAttributes->SetGUID(
MF_DEVSOURCE_ATTRIBUTE_SOURCE_TYPE,
MF_DEVSOURCE_ATTRIBUTE_SOURCE_TYPE_AUDCAP_GUID
);
}
// Enumerate devices.
if (SUCCEEDED(hr))
{
// Enumerate the device list.
hr = MFEnumDeviceSources(pAttributes, &(*param).ppDevices, &(*param).count);
}
// Safe release.
SafeRelease(&pAttributes);
}
GetAudioCaptureDevices
是'MediaCapture'class中的静态方法,可以随时调用。
我使用了 Microsoft MSDN 提供的教程来枚举音频设备。
枚举代码如下:
HRESULT CreateAudioDeviceSource(IMFMediaSource **ppSource)
{
*ppSource = NULL;
IMFMediaSource *pSource = NULL;
IMFAttributes *pAttributes = NULL;
IMFActivate **ppDevices = NULL;
// Create an attribute store to specify the enumeration parameters.
HRESULT hr = MFCreateAttributes(&pAttributes, 1);
if (FAILED(hr))
{
goto done;
}
// Source type: audio capture devices
hr = pAttributes->SetGUID(
MF_DEVSOURCE_ATTRIBUTE_SOURCE_TYPE,
MF_DEVSOURCE_ATTRIBUTE_SOURCE_TYPE_AUDCAP_GUID
);
if (FAILED(hr))
{
goto done;
}
// Enumerate devices.
UINT32 count;
hr = MFEnumDeviceSources(pAttributes, &ppDevices, &count);
std::cout << count;
if (FAILED(hr))
{
std::cout << "Enum Failed";
goto done;
}
if (count == 0)
{
std::cout << "empty";
hr = E_FAIL;
goto done;
}
// Create the media source object.
hr = ppDevices[0]->ActivateObject(IID_PPV_ARGS(&pSource));
if (FAILED(hr))
{
goto done;
}
*ppSource = pSource;
(*ppSource)->AddRef();
done:
SafeRelease(&pAttributes);
for (DWORD i = 0; i < count; i++)
{
SafeRelease(&ppDevices[i]);
}
CoTaskMemFree(ppDevices);
SafeRelease(&pSource);
return hr;
}
但是我调用枚举设备的函数失败了。我收到消息 "Enum Failed"。所以我不知道为什么会出现这个问题。
拜托,非常感谢!
参考:https://msdn.microsoft.com/en-us/library/dd317912(v=vs.85).aspx
示例代码 Windows Media Foundation 枚举音频设备,设备捕获 struct
struct CaptureDeviceParam
{
/// <summary>
/// The array of devices.
/// </summary>
IMFActivate **ppDevices;
/// <summary>
/// Device count.
/// </summary>
UINT32 count;
/// <summary>
/// Device selection.
/// </summary>
UINT32 selection;
};
和enum
设备方法。
/// <summary>
/// Get the audio capture devices.
/// </summary>
/// <param name="param">The capture device param.</param>
void MediaCapture::GetAudioCaptureDevices(CaptureDeviceParam *param)
{
HRESULT hr = S_OK;
IMFAttributes *pAttributes = NULL;
// Initialize an attribute store to specify enumeration parameters.
hr = MFCreateAttributes(&pAttributes, 1);
// Ask for source type = audio capture devices
if (SUCCEEDED(hr))
{
// Set the device attribute.
hr = pAttributes->SetGUID(
MF_DEVSOURCE_ATTRIBUTE_SOURCE_TYPE,
MF_DEVSOURCE_ATTRIBUTE_SOURCE_TYPE_AUDCAP_GUID
);
}
// Enumerate devices.
if (SUCCEEDED(hr))
{
// Enumerate the device list.
hr = MFEnumDeviceSources(pAttributes, &(*param).ppDevices, &(*param).count);
}
// Safe release.
SafeRelease(&pAttributes);
}
GetAudioCaptureDevices
是'MediaCapture'class中的静态方法,可以随时调用。