MJPG解码ICDecompressBegin失败

Question

从网上下了M3JPEG32.dll，安装之后，视频编解码器中能够看到。
代码如下：
m_hic = ICOpen( ICTYPE_VIDEO,
mmioFOURCC('M','J','P','G'),
ICMODE_DECOMPRESS );
memset(m_lpbiIn,0,sizeof(BITMAPINFO)); 
m_lpbiIn->bmiHeader.biSize            = sizeof(BITMAPINFOHEADER);   
m_lpbiIn->bmiHeader.biCompression     = mmioFOURCC('M','J','P','G');
m_lpbiIn->bmiHeader.biWidth           = m_tCapParam.m_bmpCap.bmiHeader.biWidth;
m_lpbiIn->bmiHeader.biHeight          = m_tCapParam.m_bmpCap.bmiHeader.biHeight;
m_lpbiIn->bmiHeader.biPlanes          = 1;
m_lpbiIn->bmiHeader.biBitCount        = 24; m_lpbiIn->bmiHeader.biSizeImage       = m_tCapParam.m_bmpCap.bmiHeader.biWidth *
m_tCapParam.m_bmpCap.bmiHeader.biHeight * 3;
m_lpbiIn->bmiHeader.biXPelsPerMeter   = 0;
m_lpbiIn->bmiHeader.biYPelsPerMeter   = 0;
m_lpbiIn->bmiHeader.biClrUsed         = 0;
m_lpbiIn->bmiHeader.biClrImportant    = 0; 
memset(m_lpbiOut,0,sizeof(BITMAPINFO));
m_lpbiOut->bmiHeader.biSize           = sizeof(BITMAPINFOHEADER); 
m_lpbiOut->bmiHeader.biCompression    = mmioFOURCC('I','4','2','0');
m_lpbiOut->bmiHeader.biWidth          = m_tCapParam.m_bmpCap.bmiHeader.biWidth;
m_lpbiOut->bmiHeader.biHeight         = m_tCapParam.m_bmpCap.bmiHeader.biHeight;
m_lpbiOut->bmiHeader.biPlanes         = 1;
m_lpbiOut->bmiHeader.biBitCount       = 16;
m_lpbiOut->bmiHeader.biSizeImage      = m_tCapParam.m_bmpCap.bmiHeader.biWidth *  m_tCapParam.m_bmpCap.bmiHeader.biHeight * m_lpbiOut->bmiHeader.biBitCount / 8;
m_lpbiOut->bmiHeader.biXPelsPerMeter  = 0;
m_lpbiOut->bmiHeader.biYPelsPerMeter  = 0;
m_lpbiOut->bmiHeader.biClrUsed        = 0;
m_lpbiOut->bmiHeader.biClrImportant   = 0; u32 dwRet = ::ICDecompressBegin(m_hic,m_lpbiIn,m_lpbiOut);        返回dwRet 为ICERR_BADFORMAT，请问一下，为什么会格式错误呢？