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

/* 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[8][8]=

					{   

						4096,    4096,    4096,    4096,    4096,    4096,    4096,       4096,

			5681,    4816,    3218,    1130,   -1130,   -3218,   -4816,      -5681,

			5352,    2217,   -2217,   -5352,   -5352,   -2217,    2217,   5352,

			4816,   -1130,   -5681,   -3218,    3218,    5681,    1130,  -4816,

			4096,   -4096,   -4096,    4096,    4096,   -4096,   -4096,   4096,

			3218,   -5681,    1130,    4816,   -4816,   -1130,    5681,  -3218,

			2217,   -5352,    5352,   -2217,   -2217,    5352,   -5352,   2217,

			1130,   -3218,    4816,   -5681,    5681,   -4816,    3218,  -1130

					};







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

/* 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*/

}



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