Coverage Report

Created: 2025-07-11 06:48

/src/speex/libspeex/vbr.c
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/* Copyright (C) 2002 Jean-Marc Valin
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   File: vbr.c
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   VBR-related routines
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   Redistribution and use in source and binary forms, with or without
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   modification, are permitted provided that the following conditions
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   are met:
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   - Redistributions of source code must retain the above copyright
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   notice, this list of conditions and the following disclaimer.
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   - Redistributions in binary form must reproduce the above copyright
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   notice, this list of conditions and the following disclaimer in the
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   documentation and/or other materials provided with the distribution.
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   - Neither the name of the Xiph.org Foundation nor the names of its
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   contributors may be used to endorse or promote products derived from
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   this software without specific prior written permission.
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   THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
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   ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
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   LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
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   A PARTICULAR PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE FOUNDATION OR
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   CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
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   EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
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   PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
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   PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF
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   LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
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   NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
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   SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
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*/
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#ifdef HAVE_CONFIG_H
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#include "config.h"
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#endif
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#include "vbr.h"
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#include <math.h>
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#define sqr(x) ((x)*(x))
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#define MIN_ENERGY 6000
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#define NOISE_POW .3
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#ifndef DISABLE_VBR
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const float vbr_nb_thresh[9][11]={
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   {-1.0f, -1.0f, -1.0f, -1.0f, -1.0f, -1.0f, -1.0f, -1.0f, -1.0f, -1.0f, -1.0f}, /*   CNG   */
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   { 4.0f,  2.5f,  2.0f,  1.2f,  0.5f,-0.25f, -0.5f, -0.7f, -0.8f, -0.9f, -1.0f}, /*  2 kbps */
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   {10.0f,  6.5f,  5.2f,  4.5f,  3.9f, 3.7f,  3.0f,  2.5f,  2.3f,  1.8f,  1.0f}, /*  6 kbps */
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   {11.0f,  8.8f,  7.5f,  6.5f,  5.0f,  4.2f,  3.9f,  3.9f,  3.5f,  3.0f,  1.0f}, /*  8 kbps */
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   {11.0f, 11.0f,  9.9f,  8.5f,  7.0f, 5.25f,  4.5f,  4.0f,  4.0f,  4.0f,  2.0f}, /* 11 kbps */
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   {11.0f, 11.0f, 11.0f, 11.0f,  9.5f, 9.25f,  8.0f,  7.0f,  5.0f,  4.0f,  3.0f}, /* 15 kbps */
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   {11.0f, 11.0f, 11.0f, 11.0f, 11.0f, 11.0f,  9.5f,  8.5f,  6.2f,  5.2f,  5.0f}, /* 18 kbps */
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   {11.0f, 11.0f, 11.0f, 11.0f, 11.0f, 11.0f, 11.0f, 11.0f, 10.0f,  9.8f,  7.5f}, /* 24 kbps */
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   { 7.0f,  4.5f,  3.7f,  3.0f,  2.5f,  1.0f,  1.8f,  1.5f,  1.0f,  0.0f,  0.0f}  /*  4 kbps */
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};
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const float vbr_hb_thresh[5][11]={
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   {-1.0f, -1.0f, -1.0f, -1.0f, -1.0f, -1.0f, -1.0f, -1.0f, -1.0f, -1.0f, -1.0f}, /* silence */
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   {-1.0f, -1.0f, -1.0f, -1.0f, -1.0f, -1.0f, -1.0f, -1.0f, -1.0f, -1.0f, -1.0f}, /*  2 kbps */
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   {11.0f, 11.0f,  9.5f,  8.5f,  7.5f,  6.0f,  5.0f,  3.9f,  3.0f,  2.0f,  1.0f}, /*  6 kbps */
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   {11.0f, 11.0f, 11.0f, 11.0f, 11.0f,  9.5f,  8.7f,  7.8f,  7.0f,  6.5f,  4.0f}, /* 10 kbps */
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   {11.0f, 11.0f, 11.0f, 11.0f, 11.0f, 11.0f, 11.0f, 11.0f,  9.8f,  7.5f,  5.5f}  /* 18 kbps */
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};
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const float vbr_uhb_thresh[2][11]={
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   {-1.0f, -1.0f, -1.0f, -1.0f, -1.0f, -1.0f, -1.0f, -1.0f, -1.0f, -1.0f, -1.0f}, /* silence */
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   { 3.9f,  2.5f,  0.0f,  0.0f,  0.0f,  0.0f,  0.0f,  0.0f,  0.0f,  0.0f, -1.0f}  /*  2 kbps */
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};
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void vbr_init(VBRState *vbr)
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0
{
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   int i;
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   vbr->average_energy=1600000;
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   vbr->last_energy=1;
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   vbr->accum_sum=0;
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   vbr->soft_pitch=0;
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   vbr->last_pitch_coef=0;
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   vbr->last_quality=0;
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   vbr->noise_accum = .05*pow(MIN_ENERGY, NOISE_POW);
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   vbr->noise_accum_count=.05;
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   vbr->noise_level=vbr->noise_accum/vbr->noise_accum_count;
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   vbr->consec_noise=0;
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   for (i=0;i<VBR_MEMORY_SIZE;i++)
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      vbr->last_log_energy[i] = log(MIN_ENERGY);
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}
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/*
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  This function should analyse the signal and decide how critical the
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  coding error will be perceptually. The following factors should be
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  taken into account:
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  -Attacks (positive energy derivative) should be coded with more bits
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  -Stationary voiced segments should receive more bits
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  -Segments with (very) low absolute energy should receive less bits (maybe
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  only shaped noise?)
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  -DTX for near-zero energy?
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  -Stationary fricative segments should have less bits
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  -Temporal masking: when energy slope is decreasing, decrease the bit-rate
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  -Decrease bit-rate for males (low pitch)?
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  -(wideband only) less bits in the high-band when signal is very
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  non-stationary (harder to notice high-frequency noise)???
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*/
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float vbr_analysis(VBRState *vbr, spx_word16_t *sig, int len, int pitch, float pitch_coef)
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{
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   int i;
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   float ener=0, ener1=0, ener2=0;
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   float qual=7;
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   float log_energy;
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   float non_st=0;
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   float voicing;
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   float pow_ener;
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   for (i=0;i<len>>1;i++)
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      ener1 += ((float)sig[i])*sig[i];
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   for (i=len>>1;i<len;i++)
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      ener2 += ((float)sig[i])*sig[i];
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   ener=ener1+ener2;
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   log_energy = log(ener+MIN_ENERGY);
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   for (i=0;i<VBR_MEMORY_SIZE;i++)
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      non_st += sqr(log_energy-vbr->last_log_energy[i]);
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   non_st =  non_st/(30*VBR_MEMORY_SIZE);
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   if (non_st>1)
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      non_st=1;
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   voicing = 3*(pitch_coef-.4)*fabs(pitch_coef-.4);
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   vbr->average_energy = 0.9*vbr->average_energy + .1*ener;
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   vbr->noise_level=vbr->noise_accum/vbr->noise_accum_count;
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   pow_ener = pow(ener,NOISE_POW);
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   if (vbr->noise_accum_count<.06 && ener>MIN_ENERGY)
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      vbr->noise_accum = .05*pow_ener;
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   if ((voicing<.3 && non_st < .2 && pow_ener < 1.2*vbr->noise_level)
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       || (voicing<.3 && non_st < .05 && pow_ener < 1.5*vbr->noise_level)
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       || (voicing<.4 && non_st < .05 && pow_ener < 1.2*vbr->noise_level)
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       || (voicing<0 && non_st < .05))
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   {
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      float tmp;
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      vbr->consec_noise++;
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      if (pow_ener > 3*vbr->noise_level)
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         tmp = 3*vbr->noise_level;
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      else
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         tmp = pow_ener;
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      if (vbr->consec_noise>=4)
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      {
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         vbr->noise_accum = .95*vbr->noise_accum + .05*tmp;
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         vbr->noise_accum_count = .95*vbr->noise_accum_count + .05;
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      }
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   } else {
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      vbr->consec_noise=0;
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   }
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   if (pow_ener < vbr->noise_level && ener>MIN_ENERGY)
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   {
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      vbr->noise_accum = .95*vbr->noise_accum + .05*pow_ener;
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      vbr->noise_accum_count = .95*vbr->noise_accum_count + .05;
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   }
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   /* Checking for very low absolute energy */
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   if (ener < 30000)
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   {
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      qual -= .7;
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      if (ener < 10000)
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         qual-=.7;
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      if (ener < 3000)
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         qual-=.7;
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   } else {
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      float short_diff, long_diff;
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      short_diff = log((ener+1)/(1+vbr->last_energy));
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      long_diff = log((ener+1)/(1+vbr->average_energy));
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      /*fprintf (stderr, "%f %f\n", short_diff, long_diff);*/
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      if (long_diff<-5)
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         long_diff=-5;
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      if (long_diff>2)
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         long_diff=2;
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      if (long_diff>0)
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         qual += .6*long_diff;
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      if (long_diff<0)
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         qual += .5*long_diff;
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      if (short_diff>0)
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      {
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         if (short_diff>5)
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            short_diff=5;
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         qual += 1*short_diff;
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      }
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      /* Checking for energy increases */
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      if (ener2 > 1.6*ener1)
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         qual += .5;
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   }
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   vbr->last_energy = ener;
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   vbr->soft_pitch = .8*vbr->soft_pitch + .2*pitch_coef;
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   qual += 2.2*((pitch_coef-.4) + (vbr->soft_pitch-.4));
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   if (qual < vbr->last_quality)
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      qual = .5*qual + .5*vbr->last_quality;
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   if (qual<4)
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      qual=4;
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   if (qual>10)
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      qual=10;
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   /*
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   if (vbr->consec_noise>=2)
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      qual-=1.3;
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   if (vbr->consec_noise>=5)
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      qual-=1.3;
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   if (vbr->consec_noise>=12)
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      qual-=1.3;
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   */
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   if (vbr->consec_noise>=3)
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      qual=4;
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   if (vbr->consec_noise)
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      qual -= 1.0 * (log(3.0 + vbr->consec_noise)-log(3));
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   if (qual<0)
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      qual=0;
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   if (ener<1600000)
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   {
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      if (vbr->consec_noise>2)
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         qual-=0.5*(log(3.0 + vbr->consec_noise)-log(3));
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      if (ener<10000&&vbr->consec_noise>2)
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         qual-=0.5*(log(3.0 + vbr->consec_noise)-log(3));
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      if (qual<0)
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         qual=0;
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      qual += .3*log(.0001+ener/1600000.0);
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   }
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   if (qual<-1)
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      qual=-1;
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   /*printf ("%f %f %f %f\n", qual, voicing, non_st, pow_ener/(.01+vbr->noise_level));*/
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   vbr->last_pitch_coef = pitch_coef;
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   vbr->last_quality = qual;
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   for (i=VBR_MEMORY_SIZE-1;i>0;i--)
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      vbr->last_log_energy[i] = vbr->last_log_energy[i-1];
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   vbr->last_log_energy[0] = log_energy;
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   /*printf ("VBR: %f %f %f %f\n", (float)(log_energy-log(vbr->average_energy+MIN_ENERGY)), non_st, voicing, vbr->noise_level);*/
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   return qual;
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}
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void vbr_destroy(VBRState *vbr)
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{
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0
}
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#endif /* #ifndef DISABLE_VBR */