sb_celp.cpp

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/* Copyright (C) 2002 Jean-Marc Valin 
   File: sb_celp.c

   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 <math.h>
#include "sb_celp.h"
#include "stdlib.h"
#include "filters.h"
#include "lpc.h"
#include "lsp.h"
#include "stack_alloc.h"
#include "cb_search.h"
#include "quant_lsp.h"
#include "vq.h"
#include "ltp.h"
#include "misc.h"

#ifndef M_PI
#define M_PI           3.14159265358979323846  /* pi */
#endif

#define sqr(x) ((x)*(x))

#define SUBMODE(x) st->submodes[st->submodeID]->x

#define QMF_ORDER 64
static float h0[64] = {
   3.596189e-05, -0.0001123515,
   -0.0001104587, 0.0002790277,
   0.0002298438, -0.0005953563,
   -0.0003823631, 0.00113826,
   0.0005308539, -0.001986177,
   -0.0006243724, 0.003235877,
   0.0005743159, -0.004989147,
   -0.0002584767, 0.007367171,
   -0.0004857935, -0.01050689,
   0.001894714, 0.01459396,
   -0.004313674, -0.01994365,
   0.00828756, 0.02716055,
   -0.01485397, -0.03764973,
   0.026447, 0.05543245,
   -0.05095487, -0.09779096,
   0.1382363, 0.4600981,
   0.4600981, 0.1382363,
   -0.09779096, -0.05095487,
   0.05543245, 0.026447,
   -0.03764973, -0.01485397,
   0.02716055, 0.00828756,
   -0.01994365, -0.004313674,
   0.01459396, 0.001894714,
   -0.01050689, -0.0004857935,
   0.007367171, -0.0002584767,
   -0.004989147, 0.0005743159,
   0.003235877, -0.0006243724,
   -0.001986177, 0.0005308539,
   0.00113826, -0.0003823631,
   -0.0005953563, 0.0002298438,
   0.0002790277, -0.0001104587,
   -0.0001123515, 3.596189e-05
};

static float h1[64] = {
   3.596189e-05, 0.0001123515,
   -0.0001104587, -0.0002790277,
   0.0002298438, 0.0005953563,
   -0.0003823631, -0.00113826,
   0.0005308539, 0.001986177,
   -0.0006243724, -0.003235877,
   0.0005743159, 0.004989147,
   -0.0002584767, -0.007367171,
   -0.0004857935, 0.01050689,
   0.001894714, -0.01459396,
   -0.004313674, 0.01994365,
   0.00828756, -0.02716055,
   -0.01485397, 0.03764973,
   0.026447, -0.05543245,
   -0.05095487, 0.09779096,
   0.1382363, -0.4600981,
   0.4600981, -0.1382363,
   -0.09779096, 0.05095487,
   0.05543245, -0.026447,
   -0.03764973, 0.01485397,
   0.02716055, -0.00828756,
   -0.01994365, 0.004313674,
   0.01459396, -0.001894714,
   -0.01050689, 0.0004857935,
   0.007367171, 0.0002584767,
   -0.004989147, -0.0005743159,
   0.003235877, 0.0006243724,
   -0.001986177, -0.0005308539,
   0.00113826, 0.0003823631,
   -0.0005953563, -0.0002298438,
   0.0002790277, 0.0001104587,
   -0.0001123515, -3.596189e-05
};

void *sb_encoder_init(SpeexMode *m)
{
   int i;
   SBEncState *st;
   SpeexSBMode *mode;

   st = (SBEncState*)speex_alloc(sizeof(SBEncState)+8000*sizeof(float));
   st->mode = m;
   mode = (SpeexSBMode*)m->mode;

   st->stack = ((char*)st) + sizeof(SBEncState);

   st->st_low = speex_encoder_init(mode->nb_mode);
   st->full_frame_size = 2*mode->frameSize;
   st->frame_size = mode->frameSize;
   st->subframeSize = mode->subframeSize;
   st->nbSubframes = mode->frameSize/mode->subframeSize;
   st->windowSize = st->frame_size*3/2;
   st->lpcSize=mode->lpcSize;
   st->bufSize=mode->bufSize;

   st->submodes=mode->submodes;
   st->submodeSelect = st->submodeID=mode->defaultSubmode;
   
   i=9;
   speex_encoder_ctl(st->st_low, SPEEX_SET_QUALITY, &i);

   st->lag_factor = mode->lag_factor;
   st->lpc_floor = mode->lpc_floor;
   st->gamma1=mode->gamma1;
   st->gamma2=mode->gamma2;
   st->first=1;

   st->x0d=PUSH(st->stack, st->frame_size, float);
   st->x1d=PUSH(st->stack, st->frame_size, float);
   st->high=PUSH(st->stack, st->full_frame_size, float);
   st->y0=PUSH(st->stack, st->full_frame_size, float);
   st->y1=PUSH(st->stack, st->full_frame_size, float);

   st->h0_mem=PUSH(st->stack, QMF_ORDER, float);
   st->h1_mem=PUSH(st->stack, QMF_ORDER, float);
   st->g0_mem=PUSH(st->stack, QMF_ORDER, float);
   st->g1_mem=PUSH(st->stack, QMF_ORDER, float);

   st->buf=PUSH(st->stack, st->windowSize, float);
   st->excBuf=PUSH(st->stack, st->bufSize, float);
   st->exc = st->excBuf + st->bufSize - st->windowSize;

   st->res=PUSH(st->stack, st->frame_size, float);
   st->sw=PUSH(st->stack, st->frame_size, float);
   st->target=PUSH(st->stack, st->frame_size, float);
   /*Asymmetric "pseudo-Hamming" window*/
   {
      int part1, part2;
      part1 = st->subframeSize*7/2;
      part2 = st->subframeSize*5/2;
      st->window = PUSH(st->stack, st->windowSize, float);
      for (i=0;i<part1;i++)
         st->window[i]=.54-.46*cos(M_PI*i/part1);
      for (i=0;i<part2;i++)
         st->window[part1+i]=.54+.46*cos(M_PI*i/part2);
   }

   st->lagWindow = PUSH(st->stack, st->lpcSize+1, float);
   for (i=0;i<st->lpcSize+1;i++)
      st->lagWindow[i]=exp(-.5*sqr(2*M_PI*st->lag_factor*i));

   st->rc = PUSH(st->stack, st->lpcSize, float);
   st->autocorr = PUSH(st->stack, st->lpcSize+1, float);
   st->lpc = PUSH(st->stack, st->lpcSize+1, float);
   st->bw_lpc1 = PUSH(st->stack, st->lpcSize+1, float);
   st->bw_lpc2 = PUSH(st->stack, st->lpcSize+1, float);
   st->lsp = PUSH(st->stack, st->lpcSize, float);
   st->qlsp = PUSH(st->stack, st->lpcSize, float);
   st->old_lsp = PUSH(st->stack, st->lpcSize, float);
   st->old_qlsp = PUSH(st->stack, st->lpcSize, float);
   st->interp_lsp = PUSH(st->stack, st->lpcSize, float);
   st->interp_qlsp = PUSH(st->stack, st->lpcSize, float);
   st->interp_lpc = PUSH(st->stack, st->lpcSize+1, float);
   st->interp_qlpc = PUSH(st->stack, st->lpcSize+1, float);
   st->pi_gain = PUSH(st->stack, st->nbSubframes, float);

   st->mem_sp = PUSH(st->stack, st->lpcSize, float);
   st->mem_sp2 = PUSH(st->stack, st->lpcSize, float);
   st->mem_sw = PUSH(st->stack, st->lpcSize, float);

   st->vbr_quality = 8;
   st->vbr_enabled = 0;
   st->vad_enabled = 0;
   st->abr_enabled = 0;
   st->relative_quality=0;

   st->complexity=2;
   speex_encoder_ctl(st->st_low, SPEEX_GET_SAMPLING_RATE, &st->sampling_rate);
   st->sampling_rate*=2;

   return st;
}

void sb_encoder_destroy(void *state)
{
   SBEncState *st=(SBEncState*)state;

   speex_encoder_destroy(st->st_low);

   speex_free(st);
}


int sb_encode(void *state, float *in, SpeexBits *bits)
{
   SBEncState *st;
   int i, roots, sub;
   char *stack;
   float *mem, *innov, *syn_resp;
   float *low_pi_gain, *low_exc, *low_innov;
   SpeexSBMode *mode;
   int dtx;

   st = (SBEncState*)state;
   stack=st->stack;
   mode = (SpeexSBMode*)(st->mode->mode);

   /* Compute the two sub-bands by filtering with h0 and h1*/
   qmf_decomp(in, h0, st->x0d, st->x1d, st->full_frame_size, QMF_ORDER, st->h0_mem, stack);
    
   /* Encode the narrowband part*/
   speex_encode(st->st_low, st->x0d, bits);

   /* High-band buffering / sync with low band */
   for (i=0;i<st->windowSize-st->frame_size;i++)
      st->high[i] = st->high[st->frame_size+i];
   for (i=0;i<st->frame_size;i++)
      st->high[st->windowSize-st->frame_size+i]=st->x1d[i];

   speex_move(st->excBuf, st->excBuf+st->frame_size, (st->bufSize-st->frame_size)*sizeof(float));


   low_pi_gain = PUSH(stack, st->nbSubframes, float);
   low_exc = PUSH(stack, st->frame_size, float);
   low_innov = PUSH(stack, st->frame_size, float);
   speex_encoder_ctl(st->st_low, SPEEX_GET_PI_GAIN, low_pi_gain);
   speex_encoder_ctl(st->st_low, SPEEX_GET_EXC, low_exc);
   speex_encoder_ctl(st->st_low, SPEEX_GET_INNOV, low_innov);
   
   speex_encoder_ctl(st->st_low, SPEEX_GET_LOW_MODE, &dtx);

   if (dtx==0)
      dtx=1;
   else
      dtx=0;

   /* Start encoding the high-band */
   for (i=0;i<st->windowSize;i++)
      st->buf[i] = st->high[i] * st->window[i];

   /* Compute auto-correlation */
   _spx_autocorr(st->buf, st->autocorr, st->lpcSize+1, st->windowSize);

   st->autocorr[0] += 1;        /* prevents NANs */
   st->autocorr[0] *= st->lpc_floor; /* Noise floor in auto-correlation domain */
   /* Lag windowing: equivalent to filtering in the power-spectrum domain */
   for (i=0;i<st->lpcSize+1;i++)
      st->autocorr[i] *= st->lagWindow[i];

   /* Levinson-Durbin */
   wld(st->lpc+1, st->autocorr, st->rc, st->lpcSize);
   st->lpc[0]=1;

   /* LPC to LSPs (x-domain) transform */
   roots=lpc_to_lsp (st->lpc, st->lpcSize, st->lsp, 15, 0.2, stack);
   if (roots!=st->lpcSize)
   {
      roots = lpc_to_lsp (st->lpc, st->lpcSize, st->lsp, 11, 0.02, stack);
      if (roots!=st->lpcSize) {
         /*If we can't find all LSP's, do some damage control and use a flat filter*/
         for (i=0;i<st->lpcSize;i++)
         {
            st->lsp[i]=cos(M_PI*((float)(i+1))/(st->lpcSize+1));
         }
      }
   }

   /* x-domain to angle domain*/
   for (i=0;i<st->lpcSize;i++)
      st->lsp[i] = acos(st->lsp[i]);

   /* VBR code */
   if ((st->vbr_enabled || st->vad_enabled) && !dtx)
   {
      float e_low=0, e_high=0;
      float ratio;
      if (st->abr_enabled)
      {
         float qual_change=0;
         if (st->abr_drift2 * st->abr_drift > 0)
         {
            /* Only adapt if long-term and short-term drift are the same sign */
            qual_change = -.00001*st->abr_drift/(1+st->abr_count);
            if (qual_change>.1)
               qual_change=.1;
            if (qual_change<-.1)
               qual_change=-.1;
         }
         st->vbr_quality += qual_change;
         if (st->vbr_quality>10)
            st->vbr_quality=10;
         if (st->vbr_quality<0)
            st->vbr_quality=0;
      }


      for (i=0;i<st->frame_size;i++)
      {
         e_low  += st->x0d[i]* st->x0d[i];
         e_high += st->high[i]* st->high[i];
      }
      ratio = log((1+e_high)/(1+e_low));
      speex_encoder_ctl(st->st_low, SPEEX_GET_RELATIVE_QUALITY, &st->relative_quality);
      if (ratio<-4)
         ratio=-4;
      if (ratio>2)
         ratio=2;
      /*if (ratio>-2)*/
      if (st->vbr_enabled) 
      {
         int modeid;
         modeid = mode->nb_modes-1;
         st->relative_quality+=1.0*(ratio+2);
	 if (st->relative_quality<-1)
            st->relative_quality=-1;
         while (modeid)
         {
            int v1;
            float thresh;
            v1=(int)floor(st->vbr_quality);
            if (v1==10)
               thresh = mode->vbr_thresh[modeid][v1];
            else
               thresh = (st->vbr_quality-v1)   * mode->vbr_thresh[modeid][v1+1] + 
                        (1+v1-st->vbr_quality) * mode->vbr_thresh[modeid][v1];
            if (st->relative_quality >= thresh)
               break;
            modeid--;
         }
         speex_encoder_ctl(state, SPEEX_SET_HIGH_MODE, &modeid);
         if (st->abr_enabled)
         {
            int bitrate;
            speex_encoder_ctl(state, SPEEX_GET_BITRATE, &bitrate);
            st->abr_drift+=(bitrate-st->abr_enabled);
            st->abr_drift2 = .95*st->abr_drift2 + .05*(bitrate-st->abr_enabled);
            st->abr_count += 1.0;
         }

      } else {
         /* VAD only */
         int modeid;
         if (st->relative_quality<2.0)
            modeid=1;
         else
            modeid=st->submodeSelect;
         /*speex_encoder_ctl(state, SPEEX_SET_MODE, &mode);*/
         st->submodeID=modeid;

      }
      /*fprintf (stderr, "%f %f\n", ratio, low_qual);*/
   }

   speex_bits_pack(bits, 1, 1);
   if (dtx)
      speex_bits_pack(bits, 0, SB_SUBMODE_BITS);
   else
      speex_bits_pack(bits, st->submodeID, SB_SUBMODE_BITS);

   /* If null mode (no transmission), just set a couple things to zero*/
   if (dtx || st->submodes[st->submodeID] == NULL)
   {
      for (i=0;i<st->frame_size;i++)
         st->exc[i]=st->sw[i]=VERY_SMALL;

      for (i=0;i<st->lpcSize;i++)
         st->mem_sw[i]=0;
      st->first=1;

      /* Final signal synthesis from excitation */
      iir_mem2(st->exc, st->interp_qlpc, st->high, st->subframeSize, st->lpcSize, st->mem_sp);

#ifndef RELEASE

      /* Reconstruct the original */
      fir_mem_up(st->x0d, h0, st->y0, st->full_frame_size, QMF_ORDER, st->g0_mem, stack);
      fir_mem_up(st->high, h1, st->y1, st->full_frame_size, QMF_ORDER, st->g1_mem, stack);

      for (i=0;i<st->full_frame_size;i++)
         in[i]=2*(st->y0[i]-st->y1[i]);
#endif

      if (dtx)
         return 0;
      else
         return 1;
   }


   /* LSP quantization */
   SUBMODE(lsp_quant)(st->lsp, st->qlsp, st->lpcSize, bits);   

   if (st->first)
   {
      for (i=0;i<st->lpcSize;i++)
         st->old_lsp[i] = st->lsp[i];
      for (i=0;i<st->lpcSize;i++)
         st->old_qlsp[i] = st->qlsp[i];
   }
   
   mem=PUSH(stack, st->lpcSize, float);
   syn_resp=PUSH(stack, st->subframeSize, float);
   innov = PUSH(stack, st->subframeSize, float);

   for (sub=0;sub<st->nbSubframes;sub++)
   {