DShow中完成抓图的几种方法

CFile::typeBinary);

#032              bitmapFile.Write(&hdr, sizeof(BITMAPFILEHEADER));

#033              bitmapFile.Write(buffer, bitmapSize);

#034              bitmapFile.Close();

#035              pass = true;

#036          }

#037          delete [] buffer; //数据用过之后记得要释放空间



#038          return true;

#039       }

#040   }

#041   

#042   return false;

#043 }

IMediaDet接口
IMediaDet接口可以取得媒体文件的信息。SDK里面的示例代码（没有写入文件）：

#001 long size;

#002 //取得图像帧的大小，给GetBitmapBits的第三个参数传递0 or NULL



#003 hr = pDet->GetBitmapBits(0, &size, 0, width, height);

#004 if(SUCCEEDED(hr))

#005 {

#006   char *pBuffer = new char[size];

#007   if(!pBuffer)

#008   {

#009       return E_OUTOFMEMORY;

#010   }

#011   

#012   try



#013   {

#014       hr = pDet->GetbitmapsBits(0, 0, pBuffer, width, height);

#015   }

#016   catch(...)

#017   {

#018       delete [] pBuffer;

#019       throw;

#020   }

#021   

#022   if(SUCCEEDED(hr))

#023   {

#024       BITMAPINFOHEADER *bmih = (BITMAPINFOHEADER*)pBuffer;

#025       HDC    hdcDest = GetDC(0);

#026       

#027       //Find the address of the start of the image data



#028       void *pData = pBuffer + sizeof(BITMAPINFOHEADER);

#029       

#030       //Note: In general a BITMAPINFOHEADER can include extra color



#031       //information at the end, so calculating the offset to the image



#032       //data i snot generally correct. However, the IMediaDet interface



#033       //always returns an RGB-24 image with no extra color information



#034          

#035       BITMAPINFO bmi;

#036       ZeroMemory(&bmi, sizeof(BITMAPINFO));

#037       CopyMemory(&(bmi.bmiHeader), bmih, sizeof(BITMAPINFOHEADER));

#038       HBITMAP hBitmap = CreateDIBitmap(hdcDect, bmih, CBM_INIT,

#039                     pData, &bmi, DIB_RGB_COLORS);

#040   }

#041   

#042   delete [] pBuffer;

#043 }

该方法并没有写入bitmap，具体的写入过程可以参加上面的几种方法。

关键词：DShow中完成抓图的几种办法