chuffman.cpp

这是G.723和G.729的音频编解码的源代码

#include "stdafx.h"
#include "Chuffman.h"

HuffmanCode::HuffmanCode(void)
{
  vlc_3d = MakeEhuff(8192);
  vlc_cbpcm = MakeEhuff(256);
  vlc_cbpcm_intra = MakeEhuff(256);
  vlc_cbpy = MakeEhuff(16);
  vlc_mv = MakeEhuff(65);
  LoadETable(vlc_3d_coeff,vlc_3d);
  LoadETable(vlc_cbpcm_coeff,vlc_cbpcm);
  LoadETable(vlc_cbpcm_intra_coeff,vlc_cbpcm_intra);
  LoadETable(vlc_cbpy_coeff,vlc_cbpy);
  LoadETable(vlc_mv_coeff,vlc_mv);
}

HuffmanCode::~HuffmanCode()
{
  FreeEhuff(vlc_3d);
  FreeEhuff(vlc_cbpcm);
  FreeEhuff(vlc_cbpcm_intra);
  FreeEhuff(vlc_cbpy);
  FreeEhuff(vlc_mv);
}

EHUFF * HuffmanCode::MakeEhuff(int n)
{
    EHUFF *temp;

    temp = new EHUFF;
    temp->n = n;
    temp->Hlen= new int[n];
    temp->Hcode=new int[n];
	memset(temp->Hlen,0xff,sizeof(int)*n);
	memset(temp->Hcode,0xff,sizeof(int)*n);
    return(temp);
}

void HuffmanCode::FreeEhuff(EHUFF *pHuffman)
{
    delete []pHuffman->Hlen;
	delete []pHuffman->Hcode;
	delete pHuffman;
}

void HuffmanCode::LoadETable(const int *array,EHUFF *table)
{
    while(*array>=0)
		{table->Hlen[*array] = array[1];
	     table->Hcode[*array] = array[2];
	     array+=3;
		}
}

int HuffmanCode::Encode(int val,EHUFF *huff,int& CodeValue)
{
    if (val >= huff->n) 
		return 0; // No serious error, can occur with some values 
    else if (huff->Hlen[val] < 0) 
			 return 0;
		 else 
			{CodeValue=huff->Hcode[val]; 
			 return(huff->Hlen[val]);
			}
}