为这个directshow系统创建一个自定义类，无法弄清楚如何

Question

I'm trying to learn directshow, and computer vision with opencv. But to keep the code cleaner I want to "put away" (create a class) the directshow code that I've borrowed from the internet. The code is: http://alax.info/trac/public/browser/trunk/Utilities/SetLifeCamStudioResolutionSample/SetLifeCamStudioResolutionSample.cpp

Okay. so in my vc++ project, I create a new class. I call it "directshowclass", I have directshowclass.h & .cpp.

The problem I have is that I cant figure out how to take care of all parts in the code.

Everything in _tmain() I put in one function. that one is okay.

But what do I do with:

CComPtr<IPin> GetPin(IBaseFilter* pBaseFilter, SIZE_T nIndex = 0)
{
    ....
}

And:

#pragma region Formerly located in qedit.h in Windows SDK, now obsoleted and defined within project

struct __declspec(uuid("0579154a-2b53-4994-b0d0-e773148eff85"))
ISampleGrabberCB : IUnknown
{
    //
    // Raw methods provided by interface
    //

      virtual HRESULT __stdcall SampleCB (double SampleTime,struct IMediaSample * pSample ) = 0;
      virtual HRESULT __stdcall BufferCB double SampleTime,unsigned char * pBuffer, long BufferLen ) = 0;
};

struct __declspec(uuid("6b652fff-11fe-4fce-92ad-0266b5d7c78f"))
ISampleGrabber : IUnknown
{
    //
    // Raw methods provided by interface
    //

      virtual HRESULT __stdcall SetOneShot (
        long OneShot ) = 0;
      virtual HRESULT __stdcall SetMediaType (
        struct _AMMediaType * pType ) = 0;
      virtual HRESULT __stdcall GetConnectedMediaType (
        struct _AMMediaType * pType ) = 0;
      virtual HRESULT __stdcall SetBufferSamples (
        long BufferThem ) = 0;
      virtual HRESULT __stdcall GetCurrentBuffer (
        /*[in,out]*/ long * pBufferSize,
        /*[out]*/ long * pBuffer ) = 0;
      virtual HRESULT __stdcall GetCurrentSample (
        /*[out,retval]*/ struct IMediaSample * * ppSample ) = 0;
      virtual HRESULT __stdcall SetCallback (
        struct ISampleGrabberCB * pCallback,
        long WhichMethodToCallback ) = 0;
};

struct __declspec(uuid("c1f400a0-3f08-11d3-9f0b-006008039e37"))
SampleGrabber;
    // [ default ] interface ISampleGrabber

#pragma endregion

#undef ATLENSURE_SUCCEEDED
#define ATLENSURE_SUCCEEDED(x) { HRESULT __a = (x); if(FAILED(__a)) { _tprintf(_T("Error 0x%08x in line %d\n"), __a, __LINE__); AtlThrow(__a); } }

How do I declare them in the .h file? and also .cpp file.

Answer 1

You can use following qedit.h in your code. Implement ISampleGrabberCB interface, you can make use of SampleCB or BufferCB to grab the sample.

#ifndef __qedit_h__
#define __qedit_h__

///////////////////////////////////////////////////////////////////////////////////

#pragma once

///////////////////////////////////////////////////////////////////////////////////

interface
ISampleGrabberCB
:
    public IUnknown
{
    virtual STDMETHODIMP SampleCB( double SampleTime, IMediaSample *pSample ) = 0;
    virtual STDMETHODIMP BufferCB( double SampleTime, BYTE *pBuffer, long BufferLen ) = 0;
};

///////////////////////////////////////////////////////////////////////////////////

static
const
IID IID_ISampleGrabberCB = { 0x0579154A, 0x2B53, 0x4994, { 0xB0, 0xD0, 0xE7, 0x73, 0x14, 0x8E, 0xFF, 0x85 } };

///////////////////////////////////////////////////////////////////////////////////

interface
ISampleGrabber
:
    public IUnknown
{
    virtual HRESULT STDMETHODCALLTYPE SetOneShot( BOOL OneShot ) = 0;
    virtual HRESULT STDMETHODCALLTYPE SetMediaType( const AM_MEDIA_TYPE *pType ) = 0;
    virtual HRESULT STDMETHODCALLTYPE GetConnectedMediaType( AM_MEDIA_TYPE *pType ) = 0;
    virtual HRESULT STDMETHODCALLTYPE SetBufferSamples( BOOL BufferThem ) = 0;
    virtual HRESULT STDMETHODCALLTYPE GetCurrentBuffer( long *pBufferSize, long *pBuffer ) = 0;
    virtual HRESULT STDMETHODCALLTYPE GetCurrentSample( IMediaSample **ppSample ) = 0;
    virtual HRESULT STDMETHODCALLTYPE SetCallback( ISampleGrabberCB *pCallback, long WhichMethodToCallback ) = 0;
};

///////////////////////////////////////////////////////////////////////////////////

static
const
IID IID_ISampleGrabber = { 0x6B652FFF, 0x11FE, 0x4fce, { 0x92, 0xAD, 0x02, 0x66, 0xB5, 0xD7, 0xC7, 0x8F } };

///////////////////////////////////////////////////////////////////////////////////

static
const
CLSID CLSID_SampleGrabber = { 0xC1F400A0, 0x3F08, 0x11d3, { 0x9F, 0x0B, 0x00, 0x60, 0x08, 0x03, 0x9E, 0x37 } };

///////////////////////////////////////////////////////////////////////////////////

static
const
CLSID CLSID_NullRenderer = { 0xC1F400A4, 0x3F08, 0x11d3, { 0x9F, 0x0B, 0x00, 0x60, 0x08, 0x03, 0x9E, 0x37 } };

///////////////////////////////////////////////////////////////////////////////////

static
const
CLSID CLSID_VideoEffects1Category = { 0xcc7bfb42, 0xf175, 0x11d1, { 0xa3, 0x92, 0x0, 0xe0, 0x29, 0x1f, 0x39, 0x59 } };

///////////////////////////////////////////////////////////////////////////////////

static
const
CLSID CLSID_VideoEffects2Category = { 0xcc7bfb43, 0xf175, 0x11d1, { 0xa3, 0x92, 0x0, 0xe0, 0x29, 0x1f, 0x39, 0x59 } };

///////////////////////////////////////////////////////////////////////////////////

static
const
CLSID CLSID_AudioEffects1Category = { 0xcc7bfb44, 0xf175, 0x11d1, { 0xa3, 0x92, 0x0, 0xe0, 0x29, 0x1f, 0x39, 0x59 } };

///////////////////////////////////////////////////////////////////////////////////

static
const
CLSID CLSID_AudioEffects2Category = { 0xcc7bfb45, 0xf175, 0x11d1, { 0xa3, 0x92, 0x0, 0xe0, 0x29, 0x1f, 0x39, 0x59 } };

///////////////////////////////////////////////////////////////////////////////////

#endif

Answer 2

The second fragment (#pragma region/endregion) is OK to be included on any .h in your project, visible to code that needs it.

The first fragment is a static function. You can copy it into some of your classes, or you can add "inline" specifier right before "CComPtr GetPin..." on the first line and again leave it on an .h file.