DMO播放wma简单实例

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 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
const 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FilterGraph
pGraphBuilder->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() ;
}