text: #ifndef OLD_FILM_H_
  #define OLD_FILM_H_
  #include "video_settings.h"
  #include "bitmap.h"
  #include "video_aux.h"
  
  #define ABSDIFF(x, y) ((x > y) ? x - y : y - x)
  #define ABS(x) ((x > 0) ? x : -x)
  
  // Arrays to store input image data
  static unsigned char R_in[MAX_HEIGHT][MAX_WIDTH];
  static unsigned char G_in[MAX_HEIGHT][MAX_WIDTH];
  static unsigned char B_in[MAX_HEIGHT][MAX_WIDTH];
  
  // Arrays to store output image data
  static unsigned char R_out[MAX_HEIGHT][MAX_WIDTH];
  static unsigned char G_out[MAX_HEIGHT][MAX_WIDTH];
  static unsigned char B_out[MAX_HEIGHT][MAX_WIDTH];
  
  typedef struct {
  	rgb_pixel pix;
  	unsigned char edge;
  } rgb_edge;
  
  void video_2d_filter_linebuffer(rgb_pixel in_pix[MAX_HEIGHT][MAX_WIDTH],
  																rgb_pixel out_pix[MAX_HEIGHT][MAX_WIDTH]);
  
  #endif
  