Directshow 注册 source filter

编写source filter最初需要接触的就是 filter的register和unregister，涉及到的函数有两个

DllRegisterServer()

以及

DllUnregisterServer()

在这两个函数中，完成了filter的register和unregister

而其中真正的注册，又是通过IFilterMapper2::RegisterFilter() 和 IFilterMapper2::UnregisterFilter()

来实现的。

我们需要在注册时将Filter放入不同的category，譬如 video capture source / directshow filters （使用GraphEdit可以看到，不同的category下的filters）。注册在video capture source下的filter可以在AMCapture / QQ 等AP，搜索video capture source filters出现。

 

 STDAPI DllRegisterServer()
 {
 //    return AMovieDllRegisterServer2(TRUE);
     HRESULT hr;
     IFilterMapper2 *pFM2 = NULL;
     hr = AMovieDllRegisterServer2(TRUE);
     if (FAILED(hr))
     {
         return hr;
     }
     hr = CoCreateInstance(CLSID_FilterMapper2, NULL, CLSCTX_INPROC_SERVER, IID_IFilterMapper2, (void**)&pFM2);
     if (FAILED(hr))
     {
         return hr;
     }
     hr = pFM2->RegisterFilter(CLSID_UVCPreview, L"UVC preview", NULL, &CLSID_VideoInputDeviceCategory, L"UVC preview", &rf2FilterReg);
     pFM2->Release();
     return hr;
 } // DllRegisterServer

 //
 // DllUnregisterServer
 //
 STDAPI DllUnregisterServer()
 {
 //    return AMovieDllRegisterServer2(FALSE);
     HRESULT hr;
     IFilterMapper2 *pFM2 = NULL;
     hr = AMovieDllRegisterServer2(FALSE);
     if (FAILED(hr))
     {
         return hr;
     }
     hr = CoCreateInstance(CLSID_FilterMapper2, NULL, CLSCTX_INPROC_SERVER, IID_IFilterMapper2, (void **)&pFM2);
     if (FAILED(hr))
     {
         return hr;
     }
     hr = pFM2->UnregisterFilter(&CLSID_VideoInputDeviceCategory, L"UVC preview", CLSID_UVCPreview);
     pFM2->Release();
     return hr;
 } // DllUnregisterServer

 

其中 IFilterMapper2::RegisterFilter()参数：

 HRESULT RegisterFilter(
   REFCLSID clsidFilter,
   LPCWSTR Name,
   IMoniker **ppMoniker,
   const CLSID *pclsidCategory,
   const OLECHAR *szInstance,
   const REGFILTER2 *prf2
 );
 Parameters
 clsidFilter
 [in] Class identifier (CLSID) of the filter.
 Name
 [in] Descriptive name for the filter.
 ppMoniker
 [in, out] Address of a pointer to a device moniker that determines where this filter's data will be written. Can be NULL.
 pclsidCategory
 [in] Pointer to the filter category of the filter. If NULL, the default category is CLSID_ActiveMovieFilters. (See Filter Categories.)
 szInstance
 [in] Instance data for constructing the device moniker's display name. Can be the friendly name, or the string representation of the filter CLSID. If NULL, defaults to the filter CLSID.
 prf2
 [in] Pointer to a REGFILTER2 structure containing filter information.
 Return Values
 Returns an HRESULT value. Possible values include those shown in the following table.
 Value Description
 S_OK Success.
 VFW_E_BAD_KEY Could not get registry key.

 

而Category主要包括：

 The following categories are defined in Uuids.h. They are defiined when you include Dshow.h.
 Friendly Name CLSID Merit
 Audio Capture Sources CLSID_AudioInputDeviceCategory MERIT_DO_NOT_USE
 Audio Compressors CLSID_AudioCompressorCategory MERIT_DO_NOT_USE
 Audio Renderers CLSID_AudioRendererCategory MERIT_NORMAL
 Device Control Filters CLSID_DeviceControlCategory MERIT_DO_NOT_USE
 DirectShow Filters CLSID_LegacyAmFilterCategory MERIT_NORMAL
 External Renderers CLSID_TransmitCategory MERIT_DO_NOT_USE
 Midi Renderers CLSID_MidiRendererCategory MERIT_NORMAL
 Video Capture Sources CLSID_VideoInputDeviceCategory MERIT_DO_NOT_USE
 Video Compressors CLSID_VideoCompressorCategory MERIT_DO_NOT_USE
 Video Effects (1 input) CLSID_VideoEffects1Category MERIT_DO_NOT_USE
 Video Effects (2 inputs) CLSID_VideoEffects2Category MERIT_DO_NOT_USE
 WDM Streaming Capture Devices AM_KSCATEGORY_CAPTURE MERIT_DO_NOT_USE
 WDM Streaming Crossbar Devices AM_KSCATEGORY_CROSSBAR MERIT_DO_NOT_USE
 WDM Streaming Rendering Devices AM_KSCATEGORY_RENDER MERIT_DO_NOT_USE
 WDM Streaming Tee/Splitter Devices AM_KSCATEGORY_SPLITTER MERIT_DO_NOT_USE
 WDM Streaming TV Audio Devices AM_KSCATEGORY_TVAUDIO MERIT_DO_NOT_USE
 WDM Streaming TV Tuner Devices AM_KSCATEGORY_TVTUNER MERIT_DO_NOT_USE
 WDM Streaming VBI Codecs AM_KSCATEGORY_VBICODEC MERIT_DO_NOT_USE
 ActiveMovie Filter Categories CLSID_ActiveMovieCategories Not applicable

 The following categories are defined in the header file Ks.h:
 Friendly Name CLSID Merit
 WDM Streaming Communication Transforms KSCATEGORY_COMMUNICATIONSTRANSFORM MERIT_DO_NOT_USE
 WDM Streaming Data Transforms KSCATEGORY_DATATRANSFORM MERIT_DO_NOT_USE
 WDM Streaming Interface Transforms KSCATEGORY_INTERFACETRANSFORM MERIT_DO_NOT_USE
 WDM Streaming Mixer Devices KSCATEGORY_MIXER MERIT_DO_NOT_USE

 The following categories are defined in the header file Ksmedia.h. Include these header files, in the order listed:
 #include
 #include
 Friendly Name CLSID Merit
 WDM Streaming System Audio Devices KSCATEGORY_AUDIO_DEVICE MERIT_DO_NOT_USE

 The following categories are defined in the header file Bdamedia.h. Include these header files, in the order listed:
 #include
 #include
 #include
 Friendly Name CLSID Merit
 BDA CP/CA Filters Category CLSID_CPCAFiltersCategory MERIT_NORMAL
 BDA Network Providers KSCATEGORY_BDA_NETWORK_PROVIDER MERIT_NORMAL
 BDA Receiver Components KSCATEGORY_BDA_RECEIVER_COMPONENT MERIT_NORMAL
 BDA Rendering Filters KSCATEGORY_IP_SINK MERIT_DO_NOT_USE
 BDA Source Filters KSCATEGORY_BDA_NETWORK_TUNER MERIT_DO_NOT_USE
 BDA Transport Information Renderers KSCATEGORY_BDA_TRANSPORT_INFORMATION MERIT_NORMAL

其中：

CLSID_VideoInputDeviceCategory， 注册到此category后，filter会出现在video capture source category下，被AMCapture / QQ等AP搜索到。

CLSID_LegacyAmFilterCategory， 注册到此category后，filter会出现在 directshow filters category，大部分的filter注册在此category。

 

需要注意的是 register / unregister 必须在同一个category， 使用同一 REFCLSID， 否则会出现register error。

譬如：

0x80070002 ： register / unregister 未在同一个 category

0x80070005 ： register / unregister 权限不够 （vista下权限管理，需要在administor下register/unregister filter）