/*
 * Copyright (c) 1999-2000 University of California, Riverside.
 * Permission to copy is granted provided that this header remains
 * intact.  This software is provided with no warranties.
 *
 * Version : 1.0
 * Version : 2.0 (changed to run on PC) 2/18/01
 * Version : 3.0 (changed to use as small variables as possible) 2/25/01
 *
 */

/*--------------------------------------------------------------------------*/

// This file does a Discrete Cosine Transform (DCT) on the 8X8 matrix inBuffer
// It then does the reconstruction of the result.
// The reconstruction should be similar, but not exactly equal to inBuffer

#pragma SMALL
#include<stdio.h>
#include <reg51.h>

const char code COS_TABLE[8][8] = {
    {64,   62,   59,   53,   45,   35,   24,   12},
	{64,   53,   24,  -13,  -46,  -63,  -60,  -36},
	{64,   35,  -25,  -63,  -46,   12,   59,   53},
	{64,   12,  -60,  -36,   45,   53,  -25,  -63},
	{64,  -13,  -60,   35,   45,  -54,  -25,   62},
	{64,  -36,  -25,   62,  -46,  -13,   59,  -54},
	{64,  -54,   24,   12,  -46,   62,  -60,   35},
	{64,  -63,   59,  -54,   45,  -36,   24,  -13}
};  /* taken times constant 64 and 'integerized' */

const char ONE_OVER_SQRT_TWO = 45; /* taken time constant 64 and 'integerized' */

const unsigned char code inBuffer[8][8]= {
		{ 100, 90, 80, 70,  0,  0,  0, 0 },
		{ 100,  0,  0,  0, 60,  0,  0, 0 },
		{ 100,  0,  0,  0, 60,  0,  0, 0 },
		{ 100,  0,  0, 70, 60,  0,  0, 0 },
		{ 100,  0,  0,  0, 60,  0,  0, 0 },
		{ 100,  0,  0,  0,  0, 50,  0, 0 },
		{ 100,  0,  0,  0,  0, 50,  0, 0 },
		{ 100, 90, 80, 70, 60, 50,  0, 0 }
	};

long xdata outBuffer[8][8];

/*--------------------------------------------------------------------------*/

unsigned char C (char h) {
    
    return h ? 64 : ONE_OVER_SQRT_TWO; /* taken time constant 64 and 'integerized' */
}


/*--------------------------------------------------------------------------*/
long F(char u, char v, char img[8][8]) {
    
    long r;
    unsigned char x,y;
    r = 0;
    for(x=0; x<8; x++) {
		for (y=0; y<8; y++){
			r = r + ((img[x][y] * COS_TABLE[x][u] * COS_TABLE[y][v]) >> 12);
		}
	}

    return (short) (r  * C(u) * C(v) >> 14);
}


/*--------------------------------------------------------------------------*/

void CodecDoFdct(void) {
    
    unsigned char u, v;
    
    for(u=0; u<8; u++) {
        
        for(v=0; v<8; v++) {
            
            outBuffer[u][v] = F(u, v, inBuffer);
        }
    }
}

/*--------------------------------------------------------------------------*/

void Reconstruct (void) {

	char x, y, u, v;
	long xdata temp1 = 0, temp2 = 0;
      long xdata recsrct [8][8];

	for (x=0; x<8; x++) {
		for (y=0; y<8; y++) {
			temp1 = 0;
			for (u=0; u<8; u++){
				for (v=0; v<8; v++){
					temp1 = temp1 + ((C(u) * C(v) *
				 outBuffer[u][v] * COS_TABLE[x][u] * COS_TABLE[y][v]) >> 24) ;
				}
			}
			temp2 = temp1 >> 2;  /* shifted to divide by 4 */
			recsrct [x][y] = temp2;
		}

	}
}

/*--------------------------------------------------------------------------*/

void main (void) {
		
	P1 = 1;
	CodecDoFdct();
	P1 = 2;
	Reconstruct();
	P1 = 3;
}