/* Capture video input from AVI or camera, public domain. */

#include "cv.h"
#include "highgui.h"
#include <stdio.h>
#include <ctype.h>

IplImage *image = 0;

#define WINDOWNAME "Camera"

typedef unsigned char byte;

int main(int argc, char** argv) {
  CvCapture *capture = 0;
  
  if (argc == 1 || (argc == 2 && strlen(argv[1]) == 1 && isdigit(argv[1][0]))) {
    capture = cvCaptureFromCAM(argc == 2 ? argv[1][0] - '0' : 0);
  } else if (argc == 2) {
    capture = cvCaptureFromFile(argv[1]);
  }

  if (!capture) {
    printf("Could not initialize capturing...\n");
    return -1;
  }

  cvNamedWindow(WINDOWNAME, 1);

  for(;;) {
    image = cvQueryFrame(capture);
    if (!image) { break; }

    /* Pixel data is BGR, mask out B and G components. */
    for (int y = 0; y < image->height; y++) {
      for (int x = 0; x < image->width; x++) {
        byte *p = (byte *) &image->imageData[y*image->widthStep+x*image->nChannels];
        p[0] = 0;
        p[1] = 0;
      }
    }

    cvShowImage(WINDOWNAME, image);

    char c = cvWaitKey(1);
    if (c == 27) { break; }
  }

  cvReleaseCapture(&capture);
  cvDestroyWindow(WINDOWNAME);

  return 0;
}