/*********************************************************/
/*   program 4: RGB-to-YUV,YIQ conversion                */
/*                                                       */
/*   note: no main program is supplied for this example, */
/*    only the routines to perform the conversions.      */
/*********************************************************/

void rgb2yuv ( unsigned char r, unsigned char g, unsigned char b,
  long int *y, long int *u, long int * v );
void rgb2yiq();
void yuv2rgb();
void yiq2rgb();

/***********************************************/
/*       rgb2yuv: RGB-to-YUV conversion        */
/***********************************************/

void rgb2yuv ( unsigned char r, unsigned char g, unsigned char b,
  long int *y, long int *u, long int * v ) {
  *y = ((0x00004c8b * ((long)r & 0xff)) +
        (0x00009645 * ((long)g & 0xff)) +
        (0x00001d2f * ((long)b & 0xff))) >> 8;

  *u = ((0xffffda5f * ((long)r & 0xff)) +
        (0xffffb605 * ((long)g & 0xff)) +
        (0x00006f6f * ((long)b & 0xff))) >> 8;

  *v = ((0x00009d70 * ((long)r & 0xff)) +
        (0xffff7c29 * ((long)g & 0xff)) +
        (0xffffe667 * ((long)b & 0xff))) >> 8;

  return;
  }

/***********************************************/
/*       rgb2yiq: RGB-to-YIQ conversion        */
/***********************************************/

void rgb2yiq(r,g,b,y,i,q)
unsigned char r,g,b;
long int *y,*i,*q;
  {
  *y = ((0x00004c8b * ((long)r & 0xff)) +
        (0x00009645 * ((long)g & 0xff)) +
        (0x00001d2f * ((long)b & 0xff))) >> 8;

  *i = ((0x00009893 * ((long)r & 0xff)) +
        (0xffffb9dc * ((long)g & 0xff)) +
        (0xffffad92 * ((long)b & 0xff))) >> 8;

  *q = ((0x00003604 * ((long)r & 0xff)) +
        (0xffff7a1d * ((long)g & 0xff)) +
        (0xffffb021 * ((long)b & 0xff))) >> 8;

  return;
  }

/***********************************************/
/*       yuv2rgb: YUV-to-RGB conversion        */
/***********************************************/

void yuv2rgb(y,u,v,r,g,b)
long int y,u,v;
unsigned char *r,*g,*b;
  {
  *r = (unsigned char)((((0x00010000 * y) >> 24) & 0xff) +
                       (((0x00000000 * u) >> 24) & 0xff) +
                       (((0x0001672b * v) >> 24) & 0xff));

  *g = (unsigned char)((((0x00010000 * y) >> 24) & 0xff) +
                       (((0xffffa7f0 * u) >> 24) & 0xff) +
                       (((0xffff4938 * v) >> 24) & 0xff));

  *b = (unsigned char)((((0x00010000 * y) >> 24) & 0xff) +
                       (((0x0001c5e3 * u) >> 24) & 0xff) +
                       (((0x00000000 * v) >> 24) & 0xff));

  return;
  }

/***********************************************/
/*       yiq2rgb: YIQ-to-RGB conversion        */
/***********************************************/

void yiq2rgb(y,i,q,r,g,b)
long int y,i,q;
unsigned char *r,*g,*b;
  {
  *r = (unsigned char)((((0xfffedefa * y) >> 24) & 0xff) +
                       (((0x00034e56 * i) >> 24) & 0xff) +
                       (((0x00030000 * q) >> 24) & 0xff));

  *g = (unsigned char)((((0x00019b64 * y) >> 24) & 0xff) +
                       (((0xffff10e6 * i) >> 24) & 0xff) +
                       (((0x000062d0 * q) >> 24) & 0xff));

  *b = (unsigned char)((((0x0003753f * y) >> 24) & 0xff) +
                       (((0xfffc2eda * i) >> 24) & 0xff) +
                       (((0x0005e189 * q) >> 24) & 0xff));

  return;
}