is it valid in c? how can i convert this function to work in c? please help me...

[anjaly]

CV_IMPL void cvCalcOpticalFlowFarneback(
const CvArr* _prev, const CvArr* _next,
CvArr* _flow, double pyr_scale, int levels,
int winsize, int iterations, int poly_n,
double poly_sigma, int flags )
{
cv::Mat prev = cv::cvarrToMat(_prev), next = cv::cvarrToMat(_next);
cv::Mat flow = cv::cvarrToMat(_flow);
CV_Assert( flow.size() == prev.size() && flow.type() == CV_32FC2 );
cv::calcOpticalFlowFarneback( prev, next, flow, pyr_scale, levels,
winsize, iterations, poly_n, poly_sigma, flags );
}

[bluecoder]

what is this CvArr ( struct or class ) .
also it is not clear that cv::Mat .
can you throw some light on cv .