{      if (st->S[i] > 20.f*st->Smin[i]+1000.f)         active_bands+=1;   }   active_bands /= (freq_end-freq_start+1);   if (active_bands > .2f)   {      float loudness=0.f;      float rate, rate2=.2f;      st->nb_loudness_adapt++;      rate=2.0f/(1+st->nb_loudness_adapt);      if (rate < .05f)         rate = .05f;      if (rate < .1f && pow(loudness, LOUDNESS_EXP) > st->loudness)         rate = .1f;      if (rate < .2f && pow(loudness, LOUDNESS_EXP) > 3.f*st->loudness)         rate = .2f;      if (rate < .4f && pow(loudness, LOUDNESS_EXP) > 10.f*st->loudness)         rate = .4f;      for (i=2;i<N;i++)      {         loudness += scale*st->ps[i] * st->gain2[i] * st->gain2[i] * st->loudness_weight[i];      }      loudness=sqrt(loudness);      /*if (loudness < 2*pow(st->loudness, 1.0/LOUDNESS_EXP) &&        loudness*2 > pow(st->loudness, 1.0/LOUDNESS_EXP))*/      st->loudness = (1-rate)*st->loudness + (rate)*pow(loudness, LOUDNESS_EXP);            st->loudness2 = (1-rate2)*st->loudness2 + rate2*pow(st->loudness, 1.0f/LOUDNESS_EXP);      loudness = pow(st->loudness, 1.0f/LOUDNESS_EXP);      /*fprintf (stderr, "%f %f %f\n", loudness, st->loudness2, rate);*/   }      agc_gain = st->agc_level/st->loudness2;   /*fprintf (stderr, "%f %f %f %f\n", active_bands, st->loudness, st->loudness2, agc_gain);*/   if (agc_gain>200)      agc_gain = 200;   for (i=0;i<N;i++)      st->gain2[i] *= agc_gain;   }static void preprocess_analysis(SpeexPreprocessState *st, spx_int16_t *x){   int i;   int N = st->ps_size;   int N3 = 2*N - st->frame_size;   int N4 = st->frame_size - N3;   float *ps=st->ps;   /* 'Build' input frame */   for (i=0;i<N3;i++)      st->frame[i]=st->inbuf[i];   for (i=0;i<st->frame_size;i++)      st->frame[N3+i]=x[i];      /* Update inbuf */   for (i=0;i<N3;i++)      st->inbuf[i]=x[N4+i];   /* Windowing */   for (i=0;i<2*N;i++)      st->frame[i] *= st->window[i];   /* Perform FFT */   spx_drft_forward(st->fft_lookup, st->frame);   /* Power spectrum */   ps[0]=1;   for (i=1;i<N;i++)      ps[i]=1+st->frame[2*i-1]*st->frame[2*i-1] + st->frame[2*i]*st->frame[2*i];}static void update_noise_prob(SpeexPreprocessState *st){   int i;   int N = st->ps_size;   for (i=1;i<N-1;i++)      st->S[i] = 100.f+ .8f*st->S[i] + .05f*st->ps[i-1]+.1f*st->ps[i]+.05f*st->ps[i+1];      if (st->nb_preprocess<1)   {      for (i=1;i<N-1;i++)         st->Smin[i] = st->Stmp[i] = st->S[i]+100.f;   }   if (st->nb_preprocess%200==0)   {      for (i=1;i<N-1;i++)      {         st->Smin[i] = min(st->Stmp[i], st->S[i]);         st->Stmp[i] = st->S[i];      }   } else {      for (i=1;i<N-1;i++)      {         st->Smin[i] = min(st->Smin[i], st->S[i]);         st->Stmp[i] = min(st->Stmp[i], st->S[i]);            }   }   for (i=1;i<N-1;i++)   {      st->update_prob[i] *= .2f;      if (st->S[i] > 2.5*st->Smin[i])         st->update_prob[i] += .8f;      /*fprintf (stderr, "%f ", st->S[i]/st->Smin[i]);*/      /*fprintf (stderr, "%f ", st->update_prob[i]);*/   }}#define NOISE_OVERCOMPENS 1.4int speex_preprocess(SpeexPreprocessState *st, spx_int16_t *x, spx_int32_t *echo){   int i;   int is_speech=1;   float mean_post=0;   float mean_prior=0;   int N = st->ps_size;   int N3 = 2*N - st->frame_size;   int N4 = st->frame_size - N3;   float scale=.5f/N;   float *ps=st->ps;   float Zframe=0, Pframe;   preprocess_analysis(st, x);   update_noise_prob(st);   st->nb_preprocess++;   /* Noise estimation always updated for the 20 first times */   if (st->nb_adapt<10)   {      update_noise(st, ps, echo);   }   /* Deal with residual echo if provided */   if (echo)      for (i=1;i<N;i++)         st->echo_noise[i] = (.3f*st->echo_noise[i] + st->frame_size*st->frame_size*4.0*echo[i]);   /* Compute a posteriori SNR */   for (i=1;i<N;i++)   {      float tot_noise = 1.f+ NOISE_OVERCOMPENS*st->noise[i] + st->echo_noise[i] + st->reverb_estimate[i];      st->post[i] = ps[i]/tot_noise - 1.f;      if (st->post[i]>100.f)         st->post[i]=100.f;      /*if (st->post[i]<0)        st->post[i]=0;*/      mean_post+=st->post[i];   }   mean_post /= N;   if (mean_post<0.f)      mean_post=0.f;   /* Special case for first frame */   if (st->nb_adapt==1)      for (i=1;i<N;i++)         st->old_ps[i] = ps[i];   /* Compute a priori SNR */   {      /* A priori update rate */      for (i=1;i<N;i++)      {         float gamma = .1+.9*st->prior[i]*st->prior[i]/((1+st->prior[i])*(1+st->prior[i]));         float tot_noise = 1.f+ NOISE_OVERCOMPENS*st->noise[i] + st->echo_noise[i] + st->reverb_estimate[i];         /* A priori SNR update */         st->prior[i] = gamma*max(0.0f,st->post[i]) +               (1.f-gamma)* (.8*st->gain[i]*st->gain[i]*st->old_ps[i]/tot_noise + .2*st->prior[i]);                  if (st->prior[i]>100.f)            st->prior[i]=100.f;                  mean_prior+=st->prior[i];      }   }   mean_prior /= N;#if 0   for (i=0;i<N;i++)   {      fprintf (stderr, "%f ", st->prior[i]);   }   fprintf (stderr, "\n");#endif   /*fprintf (stderr, "%f %f\n", mean_prior,mean_post);*/   if (st->nb_preprocess>=20)   {      int do_update = 0;      float noise_ener=0, sig_ener=0;      /* If SNR is low (both a priori and a posteriori), update the noise estimate*/      /*if (mean_prior<.23 && mean_post < .5)*/      if (mean_prior<.23f && mean_post < .5f)         do_update = 1;      for (i=1;i<N;i++)      {         noise_ener += st->noise[i];         sig_ener += ps[i];      }      if (noise_ener > 3.f*sig_ener)         do_update = 1;      /*do_update = 0;*/      if (do_update)      {         st->consec_noise++;      } else {         st->consec_noise=0;      }   }   if (st->vad_enabled)      is_speech = speex_compute_vad(st, ps, mean_prior, mean_post);   if (st->consec_noise>=3)   {      update_noise(st, st->old_ps, echo);   } else {      for (i=1;i<N-1;i++)      {         if (st->update_prob[i]<.5f/* || st->ps[i] < st->noise[i]*/)         {            if (echo)               st->noise[i] = .95f*st->noise[i] + .05f*max(1.0f,st->ps[i]-st->frame_size*st->frame_size*4.0*echo[i]);            else               st->noise[i] = .95f*st->noise[i] + .05f*st->ps[i];         }      }   }   for (i=1;i<N;i++)   {      st->zeta[i] = .7f*st->zeta[i] + .3f*st->prior[i];   }   {      int freq_start = (int)(300.0f*2.f*N/st->sampling_rate);      int freq_end   = (int)(2000.0f*2.f*N/st->sampling_rate);      for (i=freq_start;i<freq_end;i++)      {         Zframe += st->zeta[i];               }      Zframe /= (freq_end-freq_start);   }   st->Zlast = Zframe;   Pframe = qcurve(Zframe);   /*fprintf (stderr, "%f\n", Pframe);*/   /* Compute gain according to the Ephraim-Malah algorithm */   for (i=1;i<N;i++)   {      float MM;      float theta;      float prior_ratio;      float p, q;      float zeta1;      float P1;      prior_ratio = st->prior[i]/(1.0001f+st->prior[i]);      theta = (1.f+st->post[i])*prior_ratio;      if (i==1 || i==N-1)         zeta1 = st->zeta[i];      else         zeta1 = .25f*st->zeta[i-1] + .5f*st->zeta[i] + .25f*st->zeta[i+1];      P1 = qcurve (zeta1);            /* FIXME: add global prob (P2) */      q = 1-Pframe*P1;      q = 1-P1;      if (q>.95f)         q=.95f;      p=1.f/(1.f + (q/(1.f-q))*(1.f+st->prior[i])*exp(-theta));      /*p=1;*/      /* Optimal estimator for loudness domain */      MM = hypergeom_gain(theta);      st->gain[i] = prior_ratio * MM;      /*Put some (very arbitraty) limit on the gain*/      if (st->gain[i]>2.f)      {         st->gain[i]=2.f;      }            st->reverb_estimate[i] = st->reverb_decay*st->reverb_estimate[i] + st->reverb_decay*st->reverb_level*st->gain[i]*st->gain[i]*st->ps[i];      if (st->denoise_enabled)      {         st->gain2[i] = p*p*st->gain[i];         /*st->gain2[i]=(p*sqrt(st->gain[i])+.05*(1-p))*(p*sqrt(st->gain[i])+.05*(1-p));*/         /*st->gain2[i] = pow(st->gain[i], p) * pow(.2f,1.f-p);*/      } else {         st->gain2[i]=1.f;      }   }      st->gain2[0]=st->gain[0]=0.f;   st->gain2[N-1]=st->gain[N-1]=0.f;   /*   for (i=30;i<N-2;i++)   {      st->gain[i] = st->gain2[i]*st->gain2[i] + (1-st->gain2[i])*.333*(.6*st->gain2[i-1]+st->gain2[i]+.6*st->gain2[i+1]+.4*st->gain2[i-2]+.4*st->gain2[i+2]);   }   for (i=30;i<N-2;i++)      st->gain2[i] = st->gain[i];   */   if (st->agc_enabled)      speex_compute_agc(st, mean_prior);#if 0   if (!is_speech)   {      for (i=0;i<N;i++)         st->gain2[i] = 0;   }#if 0 else {      for (i=0;i<N;i++)         st->gain2[i] = 1;   }#endif#endif   /* Apply computed gain */   for (i=1;i<N;i++)   {      st->frame[2*i-1] *= st->gain2[i];      st->frame[2*i] *= st->gain2[i];   }   /* Get rid of the DC and very low frequencies */   st->frame[0]=0;   st->frame[1]=0;   st->frame[2]=0;   /* Nyquist frequency is mostly useless too */   st->frame[2*N-1]=0;   /* Inverse FFT with 1/N scaling */   spx_drft_backward(st->fft_lookup, st->frame);   for (i=0;i<2*N;i++)      st->frame[i] *= scale;   {      float max_sample=0;      for (i=0;i<2*N;i++)         if (fabs(st->frame[i])>max_sample)            max_sample = fabs(st->frame[i]);      if (max_sample>28000.f)      {         float damp = 28000.f/max_sample;         for (i=0;i<2*N;i++)            st->frame[i] *= damp;      }   }   for (i=0;i<2*N;i++)      st->frame[i] *= st->window[i];   /* Perform overlap and add */   for (i=0;i<N3;i++)      x[i] = st->outbuf[i] + st->frame[i];   for (i=0;i<N4;i++)      x[N3+i] = st->frame[N3+i];      /* Update outbuf */   for (i=0;i<N3;i++)      st->outbuf[i] = st->frame[st->frame_size+i];   /* Save old power spectrum */   for (i=1;i<N;i++)      st->old_ps[i] = ps[i];   return is_speech;}void speex_preprocess_estimate_update(SpeexPreprocessState *st, spx_int16_t *x, spx_int32_t *echo){   int i;   int N = st->ps_size;   int N3 = 2*N - st->frame_size;   float *ps=st->ps;   preprocess_analysis(st, x);   update_noise_prob(st);   st->nb_preprocess++;      for (i=1;i<N-1;i++)   {      if (st->update_prob[i]<.5f || st->ps[i] < st->noise[i])      {         if (echo)            st->noise[i] = .95f*st->noise[i] + .1f*max(1.0f,st->ps[i]-st->frame_size*st->frame_size*4.0*echo[i]);         else            st->noise[i] = .95f*st->noise[i] + .1f*st->ps[i];      }   }   for (i=0;i<N3;i++)      st->outbuf[i] = x[st->frame_size-N3+i]*st->window[st->frame_size+i];   /* Save old power spectrum */   for (i=1;i<N;i++)      st->old_ps[i] = ps[i];   for (i=1;i<N;i++)      st->reverb_estimate[i] *= st->reverb_decay;}int speex_preprocess_ctl(SpeexPreprocessState *state, int request, void *ptr){   int i;   SpeexPreprocessState *st;   st=(SpeexPreprocessState*)state;   switch(request)   {   case SPEEX_PREPROCESS_SET_DENOISE:      st->denoise_enabled = (*(int*)ptr);      break;   case SPEEX_PREPROCESS_GET_DENOISE:      (*(int*)ptr) = st->denoise_enabled;      break;   case SPEEX_PREPROCESS_SET_AGC:      st->agc_enabled = (*(int*)ptr);      break;   case SPEEX_PREPROCESS_GET_AGC:      (*(int*)ptr) = st->agc_enabled;      break;   case SPEEX_PREPROCESS_SET_AGC_LEVEL:      st->agc_level = (*(float*)ptr);      if (st->agc_level<1)         st->agc_level=1;      if (st->agc_level>32768)         st->agc_level=32768;      break;   case SPEEX_PREPROCESS_GET_AGC_LEVEL:      (*(float*)ptr) = st->agc_level;      break;   case SPEEX_PREPROCESS_SET_VAD:      st->vad_enabled = (*(int*)ptr);      break;   case SPEEX_PREPROCESS_GET_VAD:      (*(int*)ptr) = st->vad_enabled;      break;      case SPEEX_PREPROCESS_SET_DEREVERB:      st->dereverb_enabled = (*(int*)ptr);      for (i=0;i<st->ps_size;i++)         st->reverb_estimate[i]=0;      break;   case SPEEX_PREPROCESS_GET_DEREVERB:      (*(int*)ptr) = st->dereverb_enabled;      break;   case SPEEX_PREPROCESS_SET_DEREVERB_LEVEL:      st->reverb_level = (*(float*)ptr);      break;   case SPEEX_PREPROCESS_GET_DEREVERB_LEVEL:      (*(float*)ptr) = st->reverb_level;      break;      case SPEEX_PREPROCESS_SET_DEREVERB_DECAY:      st->reverb_decay = (*(float*)ptr);      break;   case SPEEX_PREPROCESS_GET_DEREVERB_DECAY:      (*(float*)ptr) = st->reverb_decay;      break;   case SPEEX_PREPROCESS_SET_PROB_START:      st->speech_prob_start = (*(int*)ptr) / 100.0;      if ( st->speech_prob_start > 1 || st->speech_prob_start < 0 )         st->speech_prob_start = SPEEX_PROB_START_DEFAULT;      break;   case SPEEX_PREPROCESS_GET_PROB_START:      (*(int*)ptr) = st->speech_prob_start * 100;      break;   case SPEEX_PREPROCESS_SET_PROB_CONTINUE:      st->speech_prob_continue = (*(int*)ptr) / 100.0;      if ( st->speech_prob_continue > 1 || st->speech_prob_continue < 0 )         st->speech_prob_continue = SPEEX_PROB_CONTINUE_DEFAULT;      break;   case SPEEX_PREPROCESS_GET_PROB_CONTINUE:      (*(int*)ptr) = st->speech_prob_continue * 100;      break;      default:      speex_warning_int("Unknown speex_preprocess_ctl request: ", request);      return -1;   }   return 0;}