1
我想通過調用MFCreateAudioRenderer
屬性指針集來創建具有給定GUID的音頻呈現器的實例。我給自己定的所有所需的值,但調用返回E_INVALIDARG
和mftrace.exe
顯示奇怪的屬性與guid 1082E6C2-7660-4945-8E78-228A3B3329F6所需的MFCreateAudioRenderer
13808,33E0 15:09:52.27643 CMFAttributesDetours::GetUnknown @014C4550 - enter
13808,33E0 15:09:52.27644 CMFAttributesDetours::GetUnknown @014C4550 attribute not found guidKey = {1082E6C2-7660-4945-8E78-228A3B3329F6}
13808,33E0 15:09:52.27644 CMFAttributesDetours::GetUnknown @014C4550 - exit (failed hr=0xC00D36E6 MF_E_ATTRIBUTENOTFOUND)
我不能在任何地方找到這個GUID,不知道如何設置。任何建議?
最少的樣品重現:
#include <atlbase.h>
#include <atlcom.h>
#include <Mfidl.h>
#include <Mfapi.h>
#include <Mmdeviceapi.h>
#include <string>
#include <vector>
#include <map>
#include <Functiondiscoverykeys_devpkey.h>
#include <Audioclient.h>
#include <Codecapi.h>
#include <Audiopolicy.h>
#pragma comment(lib, "Mfplat.lib")
#pragma comment(lib, "Mf.lib")
int main(int argc, char** argv)
{
CoInitializeEx(nullptr, COINIT_MULTITHREADED);
CComPtr<IMMDeviceEnumerator> pMMDeviceEnumerator;
pMMDeviceEnumerator.CoCreateInstance(__uuidof(MMDeviceEnumerator));
std::map<std::wstring, CComPtr<IMMDevice>> Devices;
if (pMMDeviceEnumerator)
{
CComPtr<IMMDeviceCollection> pMMDeviceCollection;
if (SUCCEEDED(pMMDeviceEnumerator->EnumAudioEndpoints(EDataFlow::eRender, DEVICE_STATE_ACTIVE, &pMMDeviceCollection)))
{
UINT nDeviceCount = 0;
if (SUCCEEDED(pMMDeviceCollection->GetCount(&nDeviceCount)))
{
UINT nDeviceIndex = 0;
while (nDeviceIndex < nDeviceCount)
{
CComPtr<IMMDevice> pMMDevice;
if (SUCCEEDED(pMMDeviceCollection->Item(nDeviceIndex, &pMMDevice)))
{
CComPtr<IPropertyStore> pPropertyStore;
if (SUCCEEDED(pMMDevice->OpenPropertyStore(STGM_READ, &pPropertyStore)))
{
PROPVARIANT Variant;
PropVariantInit(&Variant);
if (SUCCEEDED(pPropertyStore->GetValue(PKEY_Device_FriendlyName, &Variant)))
{
wchar_t* pId = nullptr;
if (SUCCEEDED(pMMDevice->GetId(&pId)))
{
Devices.emplace(pId, pMMDevice);
CoTaskMemFree(pId);
}
}
}
}
++nDeviceIndex;
}
}
}
}
std::vector<CComPtr<IMFMediaSink>> MediaSinks;
for (const auto& Device : Devices)
{
CComPtr<IMFAttributes> pAttributes;
MFCreateAttributes(&pAttributes, 0);
CComPtr<IMFMediaSink> pAudioRenderer;
HRESULT hResult = pAttributes->SetString(MF_AUDIO_RENDERER_ATTRIBUTE_ENDPOINT_ID, Device.first.c_str());
hResult = pAttributes->SetUINT32(MF_AUDIO_RENDERER_ATTRIBUTE_ENDPOINT_ROLE, ERole::eMultimedia);
hResult = pAttributes->SetUINT32(MF_AUDIO_RENDERER_ATTRIBUTE_STREAM_CATEGORY, AUDIO_STREAM_CATEGORY::AudioCategory_BackgroundCapableMedia);
hResult = pAttributes->SetUINT32(MF_AUDIO_RENDERER_ATTRIBUTE_FLAGS, 0);
hResult = pAttributes->SetGUID(MF_AUDIO_RENDERER_ATTRIBUTE_SESSION_ID, GUID_NULL);
hResult = MFCreateAudioRenderer(pAttributes, &pAudioRenderer);
if (SUCCEEDED(hResult))
{
MediaSinks.push_back(pAudioRenderer);
}
}
CoUninitialize();
}
@dan [你還沒有停止...?](http://stackoverflow.com/questions/43850854/how-to-intercept-alt1-or-altnumber-key-pressed-event-c#comment74738138_43850854)這一個額外的標籤是好的,但一個語言標籤*不*錯誤。 –
它可能發生,你不需要這個未知的屬性。首先問題是你的其他屬性不好。我將從註釋流類別開始(使用的值已棄用)。 –
@RomanR。如果那個人被正確地抱怨,mftrace就會被註釋掉。 –