我正在寻找一种可靠的方法来将DirectShow捕获设备GUID映射到其相应的waveID值。
我找到了下面这段Chris_P的project
这个解决方案工作得很好,它依赖于一个相当晦涩的IKsPropertySet
接口来检索映射。
不幸的是,如果我尝试使用C++/CLI库中的相同技术,代码将失败并返回E_NOTIMPL
(此行为已在this问题中进行了描述,请参阅Vladimir Hmelyoff的答案)
因此,我想我可以编写一个简单的基于控制台的辅助应用程序来检索映射并打印它们。然后,我的库可以启动这个辅助应用程序,并解析重定向的输出以获得映射。
控制台程序运行良好,但是传递给枚举回调的GUID与Chris_P的解决方案传递的GUID完全不同。
事实上,它们都共享相同的基本结构:
lpGuid = 0x02ad0808 {BDF35A00-B9AC-11D0-A619-00AA00A7C000}
唯一的变化出现在GUID的最后一位,巧合的是,它们与映射的waveId值相匹配。
另一件奇怪的事情是,捕获设备描述被截断为31个字符,就好像枚举是使用WaveIn API执行的一样!
看起来像是某个DirectSound外观现在正在包装WaveIn应用程序接口。
我是否可以禁用此行为并枚举WIN32应用程序正在枚举的相同GUIDS?
以下是控制台应用程序的代码:
#include "stdafx.h"
#include <mmreg.h>
#include <initguid.h>
#include <Dsound.h>
#include <dsconf.h>
static BOOL CALLBACK DSEnumCallback(
LPGUID lpGuid,
LPCTSTR lpcstrDescription,
LPCTSTR lpcstrModule,
LPVOID lpContext
);
static BOOL GetInfoFromDSoundGUID(GUID i_sGUID, DWORD &dwWaveID);
static HRESULT DirectSoundPrivateCreate(OUT LPKSPROPERTYSET * ppKsPropertySet);
typedef WINUSERAPI HRESULT(WINAPI *LPFNDLLGETCLASSOBJECT) (const CLSID &, const IID &, void **);
BOOL GetInfoFromDSoundGUID(GUID i_sGUID, DWORD &dwWaveID) {
LPKSPROPERTYSET pKsPropertySet = NULL;
HRESULT hr;
BOOL retval = FALSE;
PDSPROPERTY_DIRECTSOUNDDEVICE_DESCRIPTION_DATA psDirectSoundDeviceDescription = NULL;
DSPROPERTY_DIRECTSOUNDDEVICE_DESCRIPTION_DATA sDirectSoundDeviceDescription;
memset(&sDirectSoundDeviceDescription, 0, sizeof(sDirectSoundDeviceDescription));
hr = DirectSoundPrivateCreate(&pKsPropertySet);
if( SUCCEEDED(hr) ) {
ULONG ulBytesReturned = 0;
sDirectSoundDeviceDescription.DeviceId = i_sGUID;
// On the first call the final size is unknown so pass the size of the struct in order to receive
// "Type" and "DataFlow" values, ulBytesReturned will be populated with bytes required for struct+strings.
hr = pKsPropertySet->Get(DSPROPSETID_DirectSoundDevice,
DSPROPERTY_DIRECTSOUNDDEVICE_DESCRIPTION,
NULL,
0,
&sDirectSoundDeviceDescription,
sizeof(sDirectSoundDeviceDescription),
&ulBytesReturned
);
if( ulBytesReturned ) {
// On the first call it notifies us of the required amount of memory in order to receive the strings.
// Allocate the required memory, the strings will be pointed to the memory space directly after the struct.
psDirectSoundDeviceDescription = (PDSPROPERTY_DIRECTSOUNDDEVICE_DESCRIPTION_DATA)new BYTE[ulBytesReturned];
*psDirectSoundDeviceDescription = sDirectSoundDeviceDescription;
hr = pKsPropertySet->Get(DSPROPSETID_DirectSoundDevice,
DSPROPERTY_DIRECTSOUNDDEVICE_DESCRIPTION,
NULL,
0,
psDirectSoundDeviceDescription,
ulBytesReturned,
&ulBytesReturned
);
dwWaveID = psDirectSoundDeviceDescription->WaveDeviceId;
delete[] psDirectSoundDeviceDescription;
retval = TRUE;
}
pKsPropertySet->Release();
}
return retval;
}
HRESULT DirectSoundPrivateCreate(OUT LPKSPROPERTYSET * ppKsPropertySet) {
HMODULE hLibDsound = NULL;
LPFNDLLGETCLASSOBJECT pfnDllGetClassObject = NULL;
LPCLASSFACTORY pClassFactory = NULL;
LPKSPROPERTYSET pKsPropertySet = NULL;
HRESULT hr = DS_OK;
// Load dsound.dll
hLibDsound = LoadLibrary(TEXT("dsound.dll"));
if( !hLibDsound ) {
hr = DSERR_GENERIC;
}
// Find DllGetClassObject
if( SUCCEEDED(hr) ) {
pfnDllGetClassObject =
(LPFNDLLGETCLASSOBJECT)GetProcAddress(hLibDsound, "DllGetClassObject");
if( !pfnDllGetClassObject ) {
hr = DSERR_GENERIC;
}
}
// Create a class factory object
if( SUCCEEDED(hr) ) {
hr = pfnDllGetClassObject(CLSID_DirectSoundPrivate, IID_IClassFactory, (LPVOID *)&pClassFactory);
}
// Create the DirectSoundPrivate object and query for an IKsPropertySet
// interface
if( SUCCEEDED(hr) ) {
hr = pClassFactory->CreateInstance(NULL, IID_IKsPropertySet, (LPVOID *)&pKsPropertySet);
}
// Release the class factory
if( pClassFactory ) {
pClassFactory->Release();
}
// Handle final success or failure
if( SUCCEEDED(hr) ) {
*ppKsPropertySet = pKsPropertySet;
} else if( pKsPropertySet ) {
pKsPropertySet->Release();
}
FreeLibrary(hLibDsound);
return hr;
}
BOOL CALLBACK DSEnumCallback(
LPGUID lpGuid,
LPCTSTR lpcstrDescription,
LPCTSTR lpcstrModule,
LPVOID lpContext
) {
LPWSTR psz = NULL;
StringFromCLSID(*lpGuid, &psz);
DWORD WaveID = 0xFFFFFFFF;
if( lpGuid ) {
GUID i_guid = *lpGuid;
GetInfoFromDSoundGUID(i_guid, WaveID);
}
if( WaveID != 0xFFFFFFFF )
wprintf(_T("%d %s\r\n"), WaveID, psz);
if( psz ) {
CoTaskMemFree(psz);
}
return TRUE;
}
int main()
{
DirectSoundCaptureEnumerate(DSEnumCallback, NULL);
Sleep(10000);
return 0;
}
https://stackoverflow.com/questions/50751255
复制相似问题