DMO播放wma简单实例

DMO介绍:

DirectX媒体对象（DirectX Media Objects，简称DMOs），是微软提供的一种流数据处理COM组件。与DirectShowfilter相比，DMO有很多相似之处。DMO结构简单、易于创建和使用。

DMO使用方式：

1.是应用程序直接使用DMO

2.在DirectShow filter中的应用。这个比较简单，只是使用了一个DMO wrapper filter。在DirectShow应用程序中，DMO是对用户透明的，所有使用DMO的工作均由DMO wrapper filter来完成（本文主要阐述此种运用方式）。

 

工程目的：

在DirectShowFilter Graph中使用DMO播放wma文件

 

相关代码：

//初始化COM组件

CoInitialize(NULL) ;

 

HRESULT hr = S_FALSE ;

 

//创建Filter Graph

IGraphBuilder * pGraphBuilder = NULL ;

Hr = ::CoCreateInstance(CLSID_FilterGraph,NULL,CLSCTX_INPROC,IID_IGraphBuilder,(void**)&pGraphBuilder);

ASSERT(SUCCEEDED(hr)) ;

 

//创建DMO wrapper filter

IBaseFilter * pDmoFilter = NULL ;

hr = ::CoCreateInstance(CLSID_DMOWrapperFilter,NULL,CLSCTX_INPROC,IID_IBaseFilter,(void**)&pDmoFilter);

ASSERT(SUCCEEDED(hr)) ;

 

//获取IID_IDMOWrapperFilter接口

IDMOWrapperFilter * pDmoWrapperFilter= NULL ;

hr = pDmoFilter->QueryInterface(IID_IDMOWrapperFilter,(void**)&pDmoWrapperFilter);

 

ASSERT(SUCCEEDED(hr)) ;

 

//初始化DMO Wrapper Filter

hr = pDmoWrapperFilter->Init(CLSID_WMAudioDecoderDMO,DMOCATEGORY_AUDIO_DECODER) ;

ASSERT(SUCCEEDED(hr)) ;

 

//将DMOWrapperFilter添加到FilterGraph

pGraphBuilder->AddFilter(pDmoFilter,L"WMA Decoder DMO") ;

 

//采用智能连接直接播放

hr = pGraphBuilder->RenderFile(L"D:\\江南.wma",NULL);

 

IMediaControl * pMediaControl = NULL ;

hr = pGraphBuilder->QueryInterface(IID_IMediaControl,(void**)&pMediaControl);

 

//hr返回值为S_FALSE，但是仍然可以播放，暂时不知道原因

hr = pMediaControl->Run() ;

 

//释放COM组件

::CoUninitialize() ;

备注：

hr = pMediaControl->Run() ;//hr返回值为S_FALSE，但是仍然可以播放，暂时不知道原因

 

 

CLSID_WMAudioDecoderDMO 定义为

const GUID CLSID_WMAudioDecoderDMO = {0x2EEB4ADF, 0x4578,0x4D10, {0xBC, 0xA7, 0xBB, 0x95, 0x5F, 0x56, 0x32, 0x0A}};

与CWMADecMediaObject的UUID定义一致，本想直接使用CLSID_CWMADecMediaObject，无奈找不到相关lib，不知道此两个CLSID之间有什么联系，待研究

class DECLSPEC_UUID("2eeb4adf-4578-4d10-bca7-bb955f56320a")

CWMADecMediaObject;

#endif

#ifndef  UNICODE#define  UNICODE#endif#include <afxwin.h>         // MFC core and standard components#include <afxext.h>         // MFC extensions#include <afxdtctl.h>// MFC support for Internet Explorer 4 Common Controls#ifndef _AFX_NO_AFXCMN_SUPPORT#include <afxcmn.h>// MFC support for Windows Common Controls#endif // _AFX_NO_AFXCMN_SUPPORT#include <streams.h>#include <dmo.h>#include <dmodshow.h>#pragma comment(lib,"dmoguids.lib") //void main(int n, TCHAR **argv) void _tmain(int n, TCHAR **argv) { if(n!=2){printf("No file input!\n"); return;}/*    IGraphBuilder *pGraph = NULL;     IMediaControl *pControl = NULL;     IMediaEvent   *pEvent = NULL;    // Initialize the COM library.     HRESULT hr = CoInitialize(NULL);     if (FAILED(hr))     {         printf("ERROR - Could not initialize COM library");         return;     }    // Create the filter graph manager and query for interfaces.     hr = CoCreateInstance(CLSID_FilterGraph, NULL, CLSCTX_INPROC_SERVER,                         IID_IGraphBuilder, (void **)&pGraph);     if (FAILED(hr))     {         printf("ERROR - Could not create the Filter Graph Manager.");         return;     }    hr = pGraph->QueryInterface(IID_IMediaControl, (void **)&pControl);     hr = pGraph->QueryInterface(IID_IMediaEvent, (void **)&pEvent);    // Build the graph. IMPORTANT: Change this string to a file on your system.     hr = pGraph->RenderFile(argv[1], NULL);  //L"C:////Example.avi", NULL); //hr = pGraph->RenderFile(L"C:\\DX90SDK\\Samples\\Media\\CLOCKTXT.avi", NULL);     if (SUCCEEDED(hr))     {         // Run the graph.         hr = pControl->Run();         if (SUCCEEDED(hr))         {             // Wait for completion.             long evCode;             pEvent->WaitForCompletion(INFINITE, &evCode);            // Note: Do not use INFINITE in a real application, because it             // can block indefinitely.         }     }     pControl->Release();     pEvent->Release();     pGraph->Release();     CoUninitialize(); */////////////////////////////////////初始化COM组件    HRESULT hr = CoInitialize(NULL);     if (FAILED(hr))     {         printf("ERROR - Could not initialize COM library");         return;     }//创建Filter GraphIGraphBuilder * pGraphBuilder = NULL ;hr = ::CoCreateInstance(CLSID_FilterGraph,NULL,CLSCTX_INPROC,IID_IGraphBuilder,(void**)&pGraphBuilder);    if (FAILED(hr))     {         printf("ERROR - Could not create the Filter Graph Manager.");         return;     }//创建DMO wrapper filterIBaseFilter * pDmoFilter = NULL ;hr = ::CoCreateInstance(CLSID_DMOWrapperFilter,NULL,CLSCTX_INPROC,IID_IBaseFilter,(void**)&pDmoFilter);ASSERT(SUCCEEDED(hr)) ;//获取IID_IDMOWrapperFilter接口IDMOWrapperFilter * pDmoWrapperFilter= NULL ;hr = pDmoFilter->QueryInterface(IID_IDMOWrapperFilter,(void**)&pDmoWrapperFilter);ASSERT(SUCCEEDED(hr)) ;//初始化DMO Wrapper Filterconst GUID CLSID_WMAudioDecoderDMO = {0x2EEB4ADF, 0x4578,0x4D10, {0xBC, 0xA7, 0xBB, 0x95, 0x5F, 0x56, 0x32, 0x0A}};hr = pDmoWrapperFilter->Init(CLSID_WMAudioDecoderDMO,DMOCATEGORY_AUDIO_DECODER) ;ASSERT(SUCCEEDED(hr)) ;//将DMOWrapperFilter添加到FilterGraphpGraphBuilder->AddFilter(pDmoFilter,L"WMA Decoder DMO") ;//采用智能连接直接播放hr = pGraphBuilder->RenderFile(argv[1],NULL);IMediaControl * pMediaControl = NULL ;IMediaEvent   *pEvent = NULL;    if (SUCCEEDED(hr))     { hr = pGraphBuilder->QueryInterface(IID_IMediaControl,(void**)&pMediaControl);hr = pGraphBuilder->QueryInterface(IID_IMediaEvent, (void **)&pEvent);//hr返回值为S_FALSE，但是仍然可以播放，暂时不知道原因hr = pMediaControl->Run() ;         if (SUCCEEDED(hr))         {             // Wait for completion.             long evCode;             pEvent->WaitForCompletion(INFINITE, &evCode);            // Note: Do not use INFINITE in a real application, because it             // can block indefinitely.         }     }     pMediaControl->Release();     pEvent->Release();     pGraphBuilder->Release();     CoUninitialize(); //释放COM组件::CoUninitialize() ;}