// 设置参数，p1=宽，p2=高，p3=帧率

AM_MEDIA_TYPE *p = NULL;

IAMStreamConfig *pSC = NULL;

pCGB2->FindInterface(&PIN_CATEGORY_CAPTURE, &MEDIATYPE_Video, pVCap,

    IID_IAMStreamConfig, (void **)&pSC);

pSC->GetFormat(&p);

VIDEOINFOHEADER *pHd = (VIDEOINFOHEADER *)p->pbFormat;

// 单位为100ns，所以每帧(10^7/p3)*100ns

pHd->AvgTimePerFrame =  / p3;

// I420格式

pHd->bmiHeader.biCompression = MAKEFOURCC('I', '', '', '');

pHd->bmiHeader.biWidth = p1;

pHd->bmiHeader.biHeight = p2;

// 一个像素点12位

pHd->bmiHeader.biBitCount = ;

// 图像大小

pHd->bmiHeader.biSizeImage = p1 * p2 *  / ;

// 图像传输率，单位bps

pHd->dwBitRate = pHd->bmiHeader.biSizeImage *  * p3;

// defined in wmsdkidl.h

p->subtype = WMMEDIASUBTYPE_I420;

p->lSampleSize = pHd->bmiHeader.biSizeImage;

pSC->SetFormat(p);

// free p

FreeAM_MEDIA_TYPE(p);

pSC->Release();

EXTERN_GUID(WMMEDIASUBTYPE_I420,

0x30323449, 0x0000, 0x0010, 0x80, 0x00, 0x00, 0xaa, 0x00, 0x38, 0x9b, 0x71);

EXTERN_GUID(WMMEDIASUBTYPE_IYUV,

0x56555949, 0x0000, 0x0010, 0x80, 0x00, 0x00, 0xaa, 0x00, 0x38, 0x9b, 0x71);