www.pudn.com > AVS_M_ver10.rar > q_gain2p.c
/*
***********************************************************************
* COPYRIGHT AND WARRANTY INFORMATION
*
* Copyright 2007 Audio Video Coding Standard, Part ¢ú
*
* This software module was developed by AVS Audio sub-group
*
* DISCLAIMER OF WARRANTY
*
* These software programs are available to the users without any
* license fee or royalty on an "as is" basis. The AVS disclaims
* any and all warranties, whether express, implied, or statutory,
* including any implied warranties of merchantability or of fitness
* for a particular purpose. In no event shall the contributors or
* the AVS be liable for any incidental, punitive, or consequential
* damages of any kind whatsoever arising from the use of this program.
*
* This disclaimer of warranty extends to the user of this program
* and user's customers, employees, agents, transferees, successors,
* and assigns.
*
* The AVS does not represent or warrant that the program furnished
* hereunder are free of infringement of any third-party patents.
* Commercial implementations of AVS, including shareware, may be
* subject to royalty fees to patent holders. Information regarding
* the AVS patent policy is available from the AVS Web site at
* http://www.avs.org.cn
*
* THIS IS NOT A GRANT OF PATENT RIGHTS - SEE THE AVS PATENT POLICY.
************************************************************************
*/
/*-------------------------------------------------------------------------*
* procedure q_gain2_plus *
* ~~~~~~~~~~~~~~~~~~~~~~ *
* Quantization of pitch and codebook gains. *
* The following routines is Q_gains updated for AMR_WB_PLUS. *
* MA prediction is removed and MEAN_ENER is now quantized with 2 bits and *
* transmitted once every ACELP frame to the gains decoder. *
* The pitch gain and the code gain are vector quantized and the *
* mean-squared weighted error criterion is used in the quantizer search. *
*-------------------------------------------------------------------------*/
#include <math.h>
#include <float.h>
#include "../include/amr_plus.h"
#define RANGE 64
int q_gain2_plus( /* (o) : index of quantizer */
float code[], /* (i) : Innovative code vector */
int lcode, /* (i) : Subframe size */
float *gain_pit, /* (i/o): Pitch gain / Quantized pitch gain */
float *gain_code, /* (i/o): code gain / Quantized codebook gain */
float *coeff, /* (i) : correlations <y1,y1>, -2<xn,y1>, */
/* <y2,y2>, -2<xn,y2> and 2<y1,y2> */
float mean_ener, /* (i) : mean_ener defined in open-loop (2 bits) */
float *g0 /* (o) : 'correction factor' */
)
{
int i, indice=0, min_ind, size;
float ener_code, gcode0;
float dist, dist_min, g_pitch, g_code;
const float *t_qua_gain, *p;
/*-----------------------------------------------------------------*
* - Find the initial quantization pitch index *
* - Set gains search range *
*-----------------------------------------------------------------*/
t_qua_gain = E_ROM_qua_gain7b;
p = (const float *) (E_ROM_qua_gain7b + RANGE); /* pt at 1/4th of table */
min_ind = 0;
g_pitch = *gain_pit;
for (i=0; i<(NB_QUA_GAIN7B-RANGE); i++, p+=2) {
if (g_pitch > *p) {
min_ind++;
}
}
size = RANGE;
min_ind=0;
size=128;
/* innovation energy (without gain) */
ener_code = 0.01F;
for(i=0; i<lcode; i++) {
ener_code += code[i] * code[i];
}
ener_code = (float)(10.0 * log10(ener_code /(float)lcode));
/* predicted codebook gain */
/* mean energy quantized with 2 bits : 18, 30, 42 or 54 dB */
gcode0 = mean_ener - ener_code;
gcode0 = (float)pow(10.0,gcode0/20.0); /* predicted gain */
/* Search for best quantizer */
dist_min = FLT_MAX;
p = (const float *) (t_qua_gain + min_ind*2);
for (i = 0; i<size; i++)
{
g_pitch = *p++; /* pitch gain */
g_code = gcode0 * *p++; /* codebook gain */
dist = g_pitch*g_pitch * coeff[0]
+ g_pitch * coeff[1]
+ g_code*g_code * coeff[2]
+ g_code * coeff[3]
+ g_pitch*g_code * coeff[4];
if (dist < dist_min)
{
dist_min = dist;
indice = i;
}
}
indice += min_ind;
*gain_pit = t_qua_gain[indice*2];
*gain_code = t_qua_gain[indice*2+1] * gcode0;
*g0 = t_qua_gain[indice*2+1];
return indice;
}