/*********************************************************************/

/* dct_main perfomes a dct and idct function on an image.            */

/*********************************************************************/



/*****************************************************

 * include files                                     *

 *****************************************************/

#include <stdio.h>

#include <stdlib.h>



#include "dct_main.h"  /* Includes and Constants used */

#pragma DATA_SECTION (image_in,"myvar0")

#pragma DATA_SECTION (image_out,"myvar1")

#include "scenary.h"  /* an h file containing input image as a 1D array */



/* 1D array to hold output image */

unsigned char image_out[IMAGE_SIZE];



/* 1D array to hold the current block */

short block[BLOCK_SIZE];





/*********************************************************************/

/* Q12 DCT coefficients (actual coefficient x 2^12 )     	         */

/*  				                                                 */

/*********************************************************************/

const short coe[12]={3135,2217,7568,8410,-1598,6149,-10498,4816,-3686,-12586,8035,-1223};







/*********************************************************************/

/* FUNCTIONS USED																		*/

/*********************************************************************/



/* dct.c */

void dct(void);



/* idct.c */

void idct(void);





/*********************************************************************/

/* MAIN FUNCTION																		*/

/*********************************************************************/

void main()

{  

	int row, col, x, y, i;



	/***************************************************

	 *             FORWARD DCT/ INVERSE DCT            *

	 ***************************************************/

	

	/* block by block processing */

	for (row=0; row<IMAGE_LEN; row+=BLOCK_LEN)

	{

		for (col=0; col<IMAGE_LEN; col+=BLOCK_LEN)

		{

			for (y=0, i=0; y<BLOCK_LEN; y++)	/* get the block from the input image */

			{

				for (x=0; x<BLOCK_LEN; x++, i++)

					block[i] = (short) image_in[(col+x)+(row+y)*IMAGE_LEN];

			}

			dct();								/* perform FDCT on this block */

			idct();								/* perform IDCT on this block */

			for (y=0, i=0; y<BLOCK_LEN; y++)	/* store block to output image */

			{

				for (x=0; x<BLOCK_LEN; x++, i++)

				{

					if(block[i]<0)

						/* Quick fix for errors occuring due to negative a values occuring after IDCT!*/

						image_out[(col+x)+(row+y)*IMAGE_LEN]=(unsigned char) (-block[i]); 

					else 

						image_out[(col+x)+(row+y)*IMAGE_LEN]=(unsigned char) block[i];

				}

			}

		}

	}

	for (;;);    /*wait*/

}



/**************************************************************************/