Question

Using the C API (not C++), how do you read in a simple video file frame by frame, and pass this frame (as a CvMat*) off for processing?

Answer 1

Something like the following:

CvCapture* cap = cvCreateFileCapture(MyVideoFile);
if (!cap) { /* handle error */ }

for(;;) {
    IplImage* frame = cvQueryFrame(cap);
    if (!frame) { /* EOF */ break; }

    CvMat tempMat;
    CvMat* myMat = cvGetMat( frame, &tempMat, 0, 0);

    // use myMat

    // Note: Don't free the frame returned by cvQueryFrame!
}   

cvReleaseCapture(&cap);