Initial import.

1 files changed, 275 insertions, 0 deletions

diff --git a/src/libspeex/vbr.c b/src/libspeex/vbr.c
new file mode 100644
index 0000000..5b7dd9b
--- /dev/null
+++ b/src/libspeex/vbr.c
@@ -0,0 +1,275 @@
+/* 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.
+
+*/
+
+#ifdef HAVE_CONFIG_H
+#include "config.h"
+#endif
+
+#include "vbr.h"
+#include <math.h>
+
+
+#define sqr(x) ((x)*(x))
+
+#define MIN_ENERGY 6000
+#define NOISE_POW .3
+
+#ifndef DISABLE_VBR
+
+const float vbr_nb_thresh[9][11]={
+   {-1.0f, -1.0f, -1.0f, -1.0f, -1.0f, -1.0f, -1.0f, -1.0f, -1.0f, -1.0f, -1.0f}, /*   CNG   */
+   { 4.0f,  2.5f,  2.0f,  1.2f,  0.5f,  0.0f, -0.5f, -0.7f, -0.8f, -0.9f, -1.0f}, /*  2 kbps */
+   {10.0f,  6.5f,  5.2f,  4.5f,  3.9f,  3.5f,  3.0f,  2.5f,  2.3f,  1.8f,  1.0f}, /*  6 kbps */
+   {11.0f,  8.8f,  7.5f,  6.5f,  5.0f,  3.9f,  3.9f,  3.9f,  3.5f,  3.0f,  1.0f}, /*  8 kbps */
+   {11.0f, 11.0f,  9.9f,  8.5f,  7.0f,  6.0f,  4.5f,  4.0f,  4.0f,  4.0f,  2.0f}, /* 11 kbps */
+   {11.0f, 11.0f, 11.0f, 11.0f,  9.5f,  8.5f,  8.0f,  7.0f,  6.0f,  5.0f,  3.0f}, /* 15 kbps */
+   {11.0f, 11.0f, 11.0f, 11.0f, 11.0f, 11.0f,  9.5f,  8.5f,  7.0f,  6.0f,  5.0f}, /* 18 kbps */
+   {11.0f, 11.0f, 11.0f, 11.0f, 11.0f, 11.0f, 11.0f, 11.0f,  9.8f,  9.5f,  7.5f}, /* 24 kbps */ 
+   { 7.0f,  4.5f,  3.7f,  3.0f,  2.5f,  2.0f,  1.8f,  1.5f,  1.0f,  0.0f,  0.0f}  /*  4 kbps */
+};
+
+
+const float vbr_hb_thresh[5][11]={
+   {-1.0f, -1.0f, -1.0f, -1.0f, -1.0f, -1.0f, -1.0f, -1.0f, -1.0f, -1.0f, -1.0f}, /* silence */
+   {-1.0f, -1.0f, -1.0f, -1.0f, -1.0f, -1.0f, -1.0f, -1.0f, -1.0f, -1.0f, -1.0f}, /*  2 kbps */
+   {11.0f, 11.0f,  9.5f,  8.5f,  7.5f,  6.0f,  5.0f,  3.9f,  3.0f,  2.0f,  1.0f}, /*  6 kbps */
+   {11.0f, 11.0f, 11.0f, 11.0f, 11.0f,  9.5f,  8.7f,  7.8f,  7.0f,  6.5f,  4.0f}, /* 10 kbps */
+   {11.0f, 11.0f, 11.0f, 11.0f, 11.0f, 11.0f, 11.0f, 11.0f,  9.8f,  7.5f,  5.5f}  /* 18 kbps */ 
+};
+
+const float vbr_uhb_thresh[2][11]={
+   {-1.0f, -1.0f, -1.0f, -1.0f, -1.0f, -1.0f, -1.0f, -1.0f, -1.0f, -1.0f, -1.0f}, /* silence */
+   { 3.9f,  2.5f,  0.0f,  0.0f,  0.0f,  0.0f,  0.0f,  0.0f,  0.0f,  0.0f, -1.0f}  /*  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(MIN_ENERGY, 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(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, spx_word16_t *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 += ((float)sig[i])*sig[i];
+
+   for (i=len>>1;i<len;i++)
+      ener2 += ((float)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,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(3));
+   if (qual<0)
+      qual=0;
+   
+   if (ener<60000)
+   {
+      if (vbr->consec_noise>2)
+         qual-=0.5*(log(3.0 + vbr->consec_noise)-log(3));
+      if (ener<10000&&vbr->consec_noise>2)
+         qual-=0.5*(log(3.0 + vbr->consec_noise)-log(3));
+      if (qual<0)
+         qual=0;
+      qual += .3*log(.0001+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)
+{
+}
+
+#endif /* #ifndef DISABLE_VBR */