ntt_vq_decoder.c

语音压缩算法

/*****************************************************************************/
/* This software module was originally developed by                          */
/*   Naoki Iwakami (NTT)                                                     */
/* and edited by                                                             */
/*   Naoki Iwakami and Satoshi Miki (NTT) on 1996-05-01,                     */
/*   Naoki Iwakami (NTT) on 1996-08-27,                                      */
/*   Naoki Iwakami (NTT) on 1997-04-18,                                      */
/*   Takehiro Moriya (NTT) on 1998-08-10,                                    */
/* in the course of development of the                                       */
/* MPEG-2 NBC/MPEG-4 Audio standard ISO/IEC 13818-7, 14496-1,2 and 3.        */
/* This software module is an implementation of a part of one or more        */
/* MPEG-2 NBC/MPEG-4 Audio tools as specified by the MPEG-2 NBC/MPEG-4 Audio */
/* standard. ISO/IEC  gives users of the MPEG-2 NBC/MPEG-4 Audio standards   */
/* free license to this software module or modifications thereof for use in  */
/* hardware or software products claiming conformance to the MPEG-2 NBC/     */
/* MPEG-4 Audio  standards. Those intending to use this software module in   */
/* hardware or software products are advised that this use may infringe      */
/* existing patents. The original developer of this software module and      */
/* his/her company, the subsequent editors and their companies, and ISO/IEC  */
/* have no liability for use of this software module or modifications        */
/* thereof in an implementation. Copyright is not released for non           */
/* MPEG-2 NBC/MPEG-4 Audio conforming products. The original developer       */
/* retains full right to use the code for his/her  own purpose, assign or    */
/* donate the code to a third party and to inhibit third party from using    */
/* the code for non MPEG-2 NBC/MPEG-4 Audio conforming products.             */
/* This copyright notice must be included in all copies or derivative works. */
/* Copyright (c)1996.                                                        */
/*****************************************************************************/

#include <math.h>
#include <stdio.h>

#include "block.h"               /* handler, defines, enums */
#include "buffersHandle.h"       /* handler, defines, enums */
#include "concealmentHandle.h"   /* handler, defines, enums */
#include "interface.h"           /* handler, defines, enums */
#include "mod_bufHandle.h"       /* handler, defines, enums */
#include "reorderspecHandle.h"   /* handler, defines, enums */
#include "resilienceHandle.h"    /* handler, defines, enums */
#include "tf_mainHandle.h"       /* handler, defines, enums */

#include "all.h"                 /* structs */
#include "nok_ltp_common.h"      /* structs */
#include "obj_descr.h"           /* structs */
#include "tf_mainStruct.h"       /* structs */
#include "tns.h"                 /* structs */

#include "allVariables.h"        /* variables */

/*#include "tf_main.h"*/
#include "bitstream.h"
#include "ntt_conf.h"
#include "aac.h"
#include "nok_lt_prediction.h"
#include "ntt_nok_pred.h"
#include "ntt_nok_lt_predict_dec.h"
#include "common_m4a.h"


void ntt_vq_decoder(ntt_INDEX  *indexp,
		    double *spectral_line_vector[MAX_TIME_CHANNELS],
                    Info   **sfbInfo)
{
    static double flat_spectrum[ntt_T_FR_MAX], spectrum[ntt_T_FR_MAX];
    int    ismp, i_sup, top;
    double spectrum_gain;
    Info*  p_sfbInfo;

    /*--- Requantize flattened MDCT coefficients ---*/
    ntt_tf_requantize_spectrum(indexp, flat_spectrum);

    /*--- Decode side information */
    ntt_tf_proc_spectrum_d(indexp, flat_spectrum, spectrum);

    /*--- Spectrum line normalization
       gain alignment of NTT & MPEG4 VM MDCT ---*/
  switch(indexp->w_type){
  case EIGHT_SHORT_SEQUENCE:
    spectrum_gain = sqrt((double)indexp->block_size_samples/8.*2.);
    p_sfbInfo= &eight_short_info;
    break;
  default: /* long */
    spectrum_gain = sqrt((double)indexp->block_size_samples*2.);
    p_sfbInfo= &only_long_info;
  }

  if(indexp->numChannel==2){
   int sb, win;
   int sfbw;
   double buf[ntt_N_FR_MAX];
/*   if(indexp->ms_mask ==1)*/
 {
    p_sfbInfo= sfbInfo[indexp->w_type];
    for( win=0; win<p_sfbInfo->nsbk; win++ ) {
     int sboffs   = win*p_sfbInfo->bins_per_sbk[win];
     for( sb=0; sb<indexp->max_sfb[0] /*p_sfbInfo->sfb_per_sbk[win]*/; sb++ ) {
       {
         if (sb==0)
           sfbw = p_sfbInfo->bk_sfb_top[sb];
         else
           sfbw = p_sfbInfo->bk_sfb_top[sb]-p_sfbInfo->bk_sfb_top[sb-1];
       }
       if( indexp->msMask[win][sb] != 0  ) {
         for (ismp=sboffs; ismp<sboffs+sfbw; ismp++){
           buf[ismp] =  spectrum[ismp] - spectrum[ismp+indexp->block_size_samples];
           spectrum[ismp] =  spectrum[ismp]+spectrum[ismp+indexp->block_size_samples];
           spectrum[ismp+indexp->block_size_samples]  = buf[ismp];
         }
       }

       sboffs += sfbw;
     }
    }
   }
  }  
  
  for (i_sup=0; i_sup<indexp->numChannel; i_sup++){
    top = i_sup * indexp->block_size_samples;
    for (ismp=0; ismp<indexp->block_size_samples; ismp++){
      spectral_line_vector[i_sup][ismp] = spectrum[ismp+top]*spectrum_gain;
    }
  }

/*	for(ismp=0;ismp<indexp->block_size_samples;ismp++)
	printf("%e\n",spectral_line_vector[0][ismp]);*/

}


int TVQ_decode_grouping( int grouping, short region_len[] )
 {
   int i, rlen, mask;

   int no_short_reg = 0;

   mask = 1 << ( 8-2 );
   rlen = 1;  /* min. length of first group is '1' */
   for( i = 1; i<8; i++ ) {
     if( (grouping & mask) == 0) {
       *region_len++ = rlen;
       no_short_reg++;
       rlen = 0;
     }
     rlen++;
     mask >>= 1;
   }
   *region_len = rlen;
   no_short_reg++;

   return( no_short_reg );
}