idct.cpp

这是G.723和G.729的音频编解码的源代码

#include <math.h>
#include "stdafx.h"
#include "color.h"
#include "DBitstream.h"
#include "sactable.h"
#include "sad.h"
#include "Dh263class.h"
#include "commonvar.h"

extern "C"
{	void idct8x8aan(short* dctcoeffshort);
	void PrevIDCTShift(short* dctcoeffshort);
}

void DH263MB::idct(short *coeff,short *block)
{

	block[0] =coeff[0];		block[1] =coeff[2];	
	block[2] =coeff[3];		block[3] =coeff[9];	

	block[4] =coeff[10];	block[5] =coeff[20];	
	block[6] =coeff[21];	block[7] =coeff[35];	
	block[8] =coeff[1];		block[9] =coeff[4];	
	block[10]=coeff[8];		block[11]=coeff[11];	

	block[12]=coeff[19];	block[13]=coeff[22];	
	block[14]=coeff[34];	block[15]=coeff[36];	
	block[16]=coeff[5]; 	block[17]=coeff[7];	
	block[18]=coeff[12];	block[19]=coeff[18];	
	
	block[20]=coeff[23];	block[21]=coeff[33];	
	block[22]=coeff[37];	block[23]=coeff[48];	
	block[24]=coeff[6];		block[25]=coeff[13];	
	block[26]=coeff[17];	block[27]=coeff[24];	
	
	block[28]=coeff[32];	block[29]=coeff[38];	
	block[30]=coeff[47];	block[31]=coeff[49];	
	block[32]=coeff[14];	block[33]=coeff[16];	
	block[34]=coeff[25];	block[35]=coeff[31];	

	block[36]=coeff[39];	block[37]=coeff[46];	
	block[38]=coeff[50];	block[39]=coeff[57];	
	block[40]=coeff[15];	block[41]=coeff[26];	
	block[42]=coeff[30];	block[43]=coeff[40];	

	block[44]=coeff[45];	block[45]=coeff[51];	
	block[46]=coeff[56];	block[47]=coeff[58];	
	block[48]=coeff[27];	block[49]=coeff[29];	
	block[50]=coeff[41];	block[51]=coeff[44];	

	block[52]=coeff[52];	block[53]=coeff[55];	
	block[54]=coeff[59];	block[55]=coeff[62];	
	block[56]=coeff[28];	block[57]=coeff[42];	
	block[58]=coeff[43];	block[59]=coeff[53];	

	block[60]=coeff[54];	block[61]=coeff[60];	
	block[62]=coeff[61];	block[63]=coeff[63];	

    // prepare the input operands to the MMX iDCT
    // shift the 12 bits to the higher part
	PrevIDCTShift(block);
	// add 0.5 to the DC value
	block[0] +=64;	

    idct8x8aan(block);
}