/* Copyright (C) 2002 Jean-Marc Valin    File: vbr.c   VBR-related routines   Redistribution and use in source and binary forms, with or without   modification, are permitted provided that the following conditions   are met:      - Redistributions of source code must retain the above copyright   notice, this list of conditions and the following disclaimer.      - Redistributions in binary form must reproduce the above copyright   notice, this list of conditions and the following disclaimer in the   documentation and/or other materials provided with the distribution.      - Neither the name of the Xiph.org Foundation nor the names of its   contributors may be used to endorse or promote products derived from   this software without specific prior written permission.      THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS   ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT   LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR   A PARTICULAR PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE FOUNDATION OR   CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,   EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,   PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR   PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF   LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING   NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS   SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.*/#include "vbr.h"#include <math.h>#define sqr(x) ((x)*(x))#define MIN_ENERGY 6000#define NOISE_POW .3 float vbr_nb_thresh[9][11]={   {-1.0, -1.0, -1.0, -1.0, -1.0, -1.0, -1.0, -1.0, -1.0, -1.0, -1.0}, /*   CNG   */   { 3.5,  2.5,  2.0,  1.2,  0.5,  0.0, -0.5, -0.7, -0.8, -0.9, -1.0}, /*  2 kbps */   {10.0,  6.5,  5.2,  4.5,  3.9,  3.5,  3.0,  2.5,  2.3,  1.8,  1.0}, /*  6 kbps */   {11.0,  8.8,  7.5,  6.5,  5.0,  3.9,  3.9,  3.9,  3.5,  3.0,  1.0}, /*  8 kbps */   {11.0, 11.0,  9.9,  9.0,  8.0,  7.0,  6.5,  6.0,  5.0,  4.0,  2.0}, /* 11 kbps */   {11.0, 11.0, 11.0, 11.0,  9.5,  9.0,  8.0,  7.0,  6.5,  5.0,  3.0}, /* 15 kbps */   {11.0, 11.0, 11.0, 11.0, 11.0, 11.0,  9.5,  8.5,  8.0,  6.5,  4.0}, /* 18 kbps */   {11.0, 11.0, 11.0, 11.0, 11.0, 11.0, 11.0, 11.0,  9.8,  7.5,  5.5}, /* 24 kbps */    { 8.0,  5.0,  3.7,  3.0,  2.5,  2.0,  1.8,  1.5,  1.0,  0.0,  0.0}  /*  4 kbps */};float vbr_hb_thresh[5][11]={   {-1.0, -1.0, -1.0, -1.0, -1.0, -1.0, -1.0, -1.0, -1.0, -1.0, -1.0}, /* silence */   {-1.0, -1.0, -1.0, -1.0, -1.0, -1.0, -1.0, -1.0, -1.0, -1.0, -1.0}, /*  2 kbps */   {11.0, 11.0,  9.5,  8.5,  7.5,  6.0,  5.0,  3.9,  3.0,  2.0,  1.0}, /*  6 kbps */   {11.0, 11.0, 11.0, 11.0, 11.0,  9.5,  8.7,  7.8,  7.0,  6.5,  4.0}, /* 10 kbps */   {11.0, 11.0, 11.0, 11.0, 11.0, 11.0, 11.0, 11.0,  9.8,  7.5,  5.5}  /* 18 kbps */ };float vbr_uhb_thresh[2][11]={   {-1.0, -1.0, -1.0, -1.0, -1.0, -1.0, -1.0, -1.0, -1.0, -1.0, -1.0}, /* silence */   { 3.9,  2.5,  0.0,  0.0,  0.0,  0.0,  0.0,  0.0,  0.0,  0.0, -1.0}  /*  2 kbps */};void vbr_init(VBRState *vbr){   int i;   vbr->average_energy=0;   vbr->last_energy=1;   vbr->accum_sum=0;   vbr->energy_alpha=.1;   vbr->soft_pitch=0;   vbr->last_pitch_coef=0;   vbr->last_quality=0;   vbr->noise_accum = .05*pow((float)MIN_ENERGY, (float)NOISE_POW);   vbr->noise_accum_count=.05;   vbr->noise_level=vbr->noise_accum/vbr->noise_accum_count;   vbr->consec_noise=0;   for (i=0;i<VBR_MEMORY_SIZE;i++)      vbr->last_log_energy[i] = log((float)MIN_ENERGY);}/*  This function should analyse the signal and decide how critical the  coding error will be perceptually. The following factors should be  taken into account:  -Attacks (positive energy derivative) should be coded with more bits  -Stationary voiced segments should receive more bits  -Segments with (very) low absolute energy should receive less bits (maybe  only shaped noise?)  -DTX for near-zero energy?  -Stationary fricative segments should have less bits  -Temporal masking: when energy slope is decreasing, decrease the bit-rate  -Decrease bit-rate for males (low pitch)?  -(wideband only) less bits in the high-band when signal is very   non-stationary (harder to notice high-frequency noise)???*/float vbr_analysis(VBRState *vbr, float *sig, int len, int pitch, float pitch_coef){   int i;   float ener=0, ener1=0, ener2=0;   float qual=7;   int va;   float log_energy;   float non_st=0;   float voicing;   float pow_ener;   for (i=0;i<len>>1;i++)      ener1 += sig[i]*sig[i];   for (i=len>>1;i<len;i++)      ener2 += sig[i]*sig[i];   ener=ener1+ener2;   log_energy = log(ener+MIN_ENERGY);   for (i=0;i<VBR_MEMORY_SIZE;i++)      non_st += sqr(log_energy-vbr->last_log_energy[i]);   non_st =  non_st/(30*VBR_MEMORY_SIZE);   if (non_st>1)      non_st=1;   voicing = 3*(pitch_coef-.4)*fabs(pitch_coef-.4);   vbr->average_energy = (1-vbr->energy_alpha)*vbr->average_energy + vbr->energy_alpha*ener;   vbr->noise_level=vbr->noise_accum/vbr->noise_accum_count;   pow_ener = pow(ener,(float)NOISE_POW);   if (vbr->noise_accum_count<.06 && ener>MIN_ENERGY)      vbr->noise_accum = .05*pow_ener;   if ((voicing<.3 && non_st < .2 && pow_ener < 1.2*vbr->noise_level)       || (voicing<.3 && non_st < .05 && pow_ener < 1.5*vbr->noise_level)       || (voicing<.4 && non_st < .05 && pow_ener < 1.2*vbr->noise_level)       || (voicing<0 && non_st < .05))   {      float tmp;      va = 0;      vbr->consec_noise++;      if (pow_ener > 3*vbr->noise_level)         tmp = 3*vbr->noise_level;      else          tmp = pow_ener;      if (vbr->consec_noise>=4)      {         vbr->noise_accum = .95*vbr->noise_accum + .05*tmp;         vbr->noise_accum_count = .95*vbr->noise_accum_count + .05;      }   } else {      va = 1;      vbr->consec_noise=0;   }   if (pow_ener < vbr->noise_level && ener>MIN_ENERGY)   {      vbr->noise_accum = .95*vbr->noise_accum + .05*pow_ener;      vbr->noise_accum_count = .95*vbr->noise_accum_count + .05;         }   /* Checking for very low absolute energy */   if (ener < 30000)   {      qual -= .7;      if (ener < 10000)         qual-=.7;      if (ener < 3000)         qual-=.7;   } else {      float short_diff, long_diff;      short_diff = log((ener+1)/(1+vbr->last_energy));      long_diff = log((ener+1)/(1+vbr->average_energy));      /*fprintf (stderr, "%f %f\n", short_diff, long_diff);*/      if (long_diff<-5)         long_diff=-5;      if (long_diff>2)         long_diff=2;      if (long_diff>0)         qual += .6*long_diff;      if (long_diff<0)         qual += .5*long_diff;      if (short_diff>0)      {         if (short_diff>5)            short_diff=5;         qual += .5*short_diff;      }      /* Checking for energy increases */      if (ener2 > 1.6*ener1)         qual += .5;   }   vbr->last_energy = ener;   vbr->soft_pitch = .6*vbr->soft_pitch + .4*pitch_coef;   qual += 2.2*((pitch_coef-.4) + (vbr->soft_pitch-.4));   if (qual < vbr->last_quality)      qual = .5*qual + .5*vbr->last_quality;   if (qual<4)      qual=4;   if (qual>10)      qual=10;      /*   if (vbr->consec_noise>=2)      qual-=1.3;   if (vbr->consec_noise>=5)      qual-=1.3;   if (vbr->consec_noise>=12)      qual-=1.3;   */   if (vbr->consec_noise>=3)      qual=4;   if (vbr->consec_noise)      qual -= 1.0 * (log(3.0 + vbr->consec_noise)-log((float)3));   if (qual<0)      qual=0;      if (ener<60000)   {      if (vbr->consec_noise>2)         qual-=0.5*(log(3.0 + vbr->consec_noise)-log((float)3));      if (ener<10000&&vbr->consec_noise>2)         qual-=0.5*(log(3.0 + vbr->consec_noise)-log((float)3));      if (qual<0)         qual=0;      qual += .3*log(ener/60000.0);   }   if (qual<-1)      qual=-1;   /*printf ("%f %f %f %f %d\n", qual, voicing, non_st, pow_ener/(.01+vbr->noise_level), va);*/   vbr->last_pitch_coef = pitch_coef;   vbr->last_quality = qual;   for (i=VBR_MEMORY_SIZE-1;i>0;i--)      vbr->last_log_energy[i] = vbr->last_log_energy[i-1];   vbr->last_log_energy[0] = log_energy;   /*printf ("VBR: %f %f %f %d %f\n", (float)(log_energy-log(vbr->average_energy+MIN_ENERGY)), non_st, voicing, va, vbr->noise_level);*/   return qual;}void vbr_destroy(VBRState *vbr){}