修改yv12像素值

YV12内存布局



 1 unsigned char *pY = (unsigned char *)pBuf;
unsigned char *pV = pY + nWidth * nHeight;
unsigned char *pU = pV + (nWidth>>1)*(nHeight>>1);

//加上出入口数字指纹,以便确认识别出来的是哪个口 
if(nPort==0)
{
pY[0]=0;
pV[0]=0;
pU[0]=0;
}
else
{
pY[0]=255;
pV[0]=255;
pU[0]=255;
}