cfiltergraph.cpp

《DirectShow开发指南》配套代码代码,需要DirectX SDK 7以上支持。

// CFilterGraph.cpp: implementation of the CFilterGraph class.
//
//////////////////////////////////////////////////////////////////////
#include "stdafx.h"
#include "streams.h"
#include "CFilterGraph.h"
#include "CDataAdmin.h"

#ifdef _DEBUG
#undef THIS_FILE
static char THIS_FILE[]=__FILE__;
#define new DEBUG_NEW
#endif


//////////////////////////////////////////////////////////////////////
// Construction/Destruction
//////////////////////////////////////////////////////////////////////

CFilterGraph::CFilterGraph(CDataAdmin *inBuffer)
{
	// Filter graph running status
	m_bRun  = false;
	m_bInit = false;

	// Interfaces
	m_pGB   = NULL;
	m_pMC   = NULL;
	m_pVW   = NULL;
	m_pME   = NULL;
	m_pMS   = NULL;
	m_pBA   = NULL;

	m_hOwner   = NULL;
	m_nLeft    = 0;
	m_nTop     = 0;
	m_nWidth   = 100;
	m_nHeight  = 100;
	m_dwGraphRegister = 0;

	// Data buffer pointer
	m_pDataList = inBuffer;
}

CFilterGraph::~CFilterGraph()
{
	m_bRun = false;
	ReleaseGraph();

	m_pDataList = NULL;
}

void CFilterGraph::ReleaseGraph(void)
{
	// Stop filter graph first
	HRESULT  hr;
	if (m_pMC != NULL)
	{
		hr = m_pMC->Stop(); 
	}

    // Relinquish ownership (IMPORTANT!) after hiding video window
    if(m_pVW != NULL)
    {
        hr = m_pVW->put_Visible(OAFALSE);
        hr = m_pVW->put_Owner(NULL);
    }

	if (m_pGB != NULL)
	{
		// Unregister....
		RemoveGraphFromRot(m_dwGraphRegister);

		// remove the filter added before
		m_pGB->RemoveFilter(m_pSourceReader);
		// media event interface
		SAFE_RELEASE(m_pME)
		// media seeking interface
		SAFE_RELEASE(m_pMS)
		// media control interface
		SAFE_RELEASE(m_pMC)
		// basic audio interface
		SAFE_RELEASE(m_pBA)
		// video window interface
		SAFE_RELEASE(m_pVW)
		// graph builder interface
		SAFE_RELEASE(m_pGB)

		SAFE_DELETE(m_pSourceStream)
		SAFE_DELETE(m_pSourceReader)			
	}
}

bool CFilterGraph::BuildGraph(void)
{
	m_bInit = false;
	//  Create filter graph
    HRESULT hr = CoCreateInstance(CLSID_FilterGraph,
                                  NULL,
                                  CLSCTX_INPROC,
                                  IID_IGraphBuilder,
                                  (void**)&m_pGB);
	if (SUCCEEDED(hr))
	{
		m_bInit = true;
		// Register...
		AddGraphToRot((IUnknown *)m_pGB, &m_dwGraphRegister);
	}

	if (m_bInit)
	{
		// Media control interface
		hr = m_pGB->QueryInterface(IID_IMediaControl, (void **)&m_pMC);
		if (FAILED(hr))
		{
			m_bInit = false;
		}
	}

	if (m_bInit)
	{
		// Media event interface
		hr = m_pGB->QueryInterface(IID_IMediaEvent, (void **)&m_pME);
		if (FAILED(hr)) 
		{
			m_bInit = false;
		}
	}
	
	if (m_bInit)
	{
		// Media video window interface
		hr = m_pGB->QueryInterface(IID_IVideoWindow, (void **)&m_pVW);
		if (FAILED(hr)) 
		{
			m_bInit = false;
		}
	}

	if (m_bInit)
	{
		// Media basic audio interface
		hr = m_pGB->QueryInterface(IID_IBasicAudio, (void **)&m_pBA);
		if (FAILED(hr)) 
		{
			m_bInit = false;
		}
	}

	if (m_bInit)
	{
		// Media seeking interface
		hr = m_pGB->QueryInterface(IID_IMediaSeeking, (void **)&m_pMS);
		if (FAILED(hr)) 
		{
			m_bInit = false;
		}
	}

	// construct source filter
	// Media type
	if (m_bInit)
	{
		CMediaType   mt;      
		mt.majortype = MEDIATYPE_Stream;
		mt.subtype   = MEDIASUBTYPE_MPEG1System;
		m_pSourceStream  = new CMemStream(m_pDataList);
		m_pSourceReader  = new CMemReader(m_pSourceStream, &mt, &hr);
		m_pSourceReader->AddRef();
		//  Add our filter
		hr = m_pGB->AddFilter(m_pSourceReader, NULL);
		if (FAILED(hr)) 
		{
			m_bInit = false;
		}  
	}

	if (m_bInit)
	{
		// Waiting for event to start filter graph
		::AfxBeginThread((AFX_THREADPROC)CFilterGraph::WaitingThrd, this);
	}

	return m_bInit;
}

void CFilterGraph::SetWindowPosition(int nLeft, int nTop, int nWidth, int nHeight)
{
	m_nLeft    = nLeft;
	m_nTop     = nTop;
	m_nWidth   = nWidth;
	m_nHeight  = nHeight;
}

bool CFilterGraph::StartGraph(void)
{
	if (m_bInit)
	{
		m_bRun = true;
		HRESULT hr  = m_pGB->Render(m_pSourceReader->GetPin(0));
		if (FAILED(hr))
		{
			m_bRun = false;
			return false;
		}

		hr = m_pVW->put_Visible(OAFALSE);
		hr = m_pVW->put_Owner((OAHWND)m_hOwner);
		hr = m_pVW->put_WindowStyle(WS_CHILD | WS_CLIPSIBLINGS | WS_CLIPCHILDREN);
		hr = m_pVW->SetWindowPosition(m_nLeft, m_nTop, m_nWidth, m_nHeight);
		// Enable the parent window to get the mouse and keyboard event in the video window
		hr = m_pVW->put_MessageDrain((OAHWND)m_hOwner);
		hr = m_pVW->put_Visible(OATRUE);
		
		// run the filter graph
		hr = m_pMC->Run();
		return true;
	}
	
	return false;
}

void CFilterGraph::SetVideoWndOwner(HWND inWnd)
{
	m_hOwner = inWnd;
}

bool CFilterGraph::IsInit(void)
{
	return m_bInit;
}

bool CFilterGraph::IsRunning(void)
{
	return m_bRun;
}

void CFilterGraph::AdjustLength(LONGLONG inAdd)
{
	if (m_pSourceStream)
	{
		m_pSourceStream->AddAvailableLength(inAdd);
	}
}

// When data buffer enough, start the filter graph
UINT CFilterGraph::WaitingThrd(void * pParam)
{
	CFilterGraph * pGraph = (CFilterGraph *) pParam;
	if (pGraph != NULL && pGraph->m_pDataList != NULL)
	{
		::WaitForSingleObject(pGraph->m_pDataList->m_hBufEnough, INFINITE);
		if (!pGraph->IsRunning())
		{
			pGraph->StartGraph();
		}
	}
	return 1;
}

bool CFilterGraph::ResetGraph(void)
{
	if (m_bRun)
	{
		// If the filter graph running, release it first
		ReleaseGraph();
	}
	// Reset the datalist
	if (m_pDataList != NULL)
	{
		m_pDataList->ResetList();
		ResetEvent(m_pDataList->m_hBufEnough);
	}
	// Build a new filter graph
	BuildGraph();
	return true;
}

///////////////////////////////////////////////////////////////////////////
HRESULT CFilterGraph::AddGraphToRot(IUnknown *pUnkGraph, DWORD *pdwRegister) 
{
    IMoniker * pMoniker;
    IRunningObjectTable *pROT;
    if (FAILED(GetRunningObjectTable(0, &pROT))) {
        return E_FAIL;
    }
    WCHAR wsz[128];
    wsprintfW(wsz, L"FilterGraph %08x pid %08x", (DWORD_PTR)pUnkGraph, GetCurrentProcessId());
    HRESULT hr = CreateItemMoniker(L"!", wsz, &pMoniker);
    if (SUCCEEDED(hr)) {
        hr = pROT->Register(0, pUnkGraph, pMoniker, pdwRegister);
        pMoniker->Release();
    }
    pROT->Release();
    return hr;
}

void CFilterGraph::RemoveGraphFromRot(DWORD pdwRegister)
{
    IRunningObjectTable *pROT;
    if (SUCCEEDED(GetRunningObjectTable(0, &pROT))) {
        pROT->Revoke(pdwRegister);
        pROT->Release();
    }
}
//////////////////////////////////////////////////////////////////////////////