For help, I call the hikvision SDK camera, and it returns the yv12 data stream after decoding, what should I do?

Python
1

My call in c++:

long g_nPort;
cv::Mat g_BGRImage;
void CALLBACK DecCBFun(long nPort, char* pBuf, long nSize, FRAME_INFO* pFrameInfo, long nUser, long nReserved2)
{
    if(pFrameInfo->nType == T_YV12)
    {
        if(g_BGRImage.empty())
        {
            g_BGRImage.create(pFrameInfo->nHeight, pFrameInfo->nWidth, CV_8UC3);
        }
        cv::Mat YUVImage(pFrameInfo->nHeight + pFrameInfo->nHeight/2, pFrameInfo->nWidth, CV_8UC1, (unsigned char*)pBuf);

        cvtColor(YUVImage, g_BGRImage, cv::COLOR_YUV2BGR_YV12);
        imshow("RGBImage", g_BGRImage);
        cv::waitKey(15);
        YUVImage.~Mat();
    }
}

I want to use pyOpencv to achieve the same function, what should I do?
The parameter pBuf is the data stream returned by yv12;
My python call:

DECODECALLBACK = CFUNCTYPE(None,c_long,c_char_p,c_long,POINTER(FRAME_INFO),c_long,c_long)
@DECODECALLBACK
def g_decode_callback (nPort:c_long, pBuf:c_char_p, nSize:c_long, pFrameInfo:POINTER(FRAME_INFO), nUser:c_long, nReserved2:c_long):
    frameInfo = pFrameInfo.contents
    #YU12
    if frameInfo.nType == T_YV12:
         srcImg = np.zeros((frameInfo.nHeight,frameInfo.nWidth,3),dtype=np.uint8)
        
        # print(srcImg)

    return 0