Add speex to trunk/deps/third_party/....

speex/libspeex/filters.c

+/* Copyright (C) 2002-2006 Jean-Marc Valin 
+   File: filters.c
+   Various analysis/synthesis filters
+
+   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 "filters.h"
+#include "stack_alloc.h"
+#include "arch.h"
+#include "math_approx.h"
+#include "ltp.h"
+#include <math.h>
+
+#ifdef _USE_SSE
+#include "filters_sse.h"
+#elif defined (ARM4_ASM) || defined(ARM5E_ASM)
+#include "filters_arm4.h"
+#elif defined (BFIN_ASM)
+#include "filters_bfin.h"
+#endif
+
+
+
+void bw_lpc(spx_word16_t gamma, const spx_coef_t *lpc_in, spx_coef_t *lpc_out, int order)
+{
+   int i;
+   spx_word16_t tmp=gamma;
+   for (i=0;i<order;i++)
+   {
+      lpc_out[i] = MULT16_16_P15(tmp,lpc_in[i]);
+      tmp = MULT16_16_P15(tmp, gamma);
+   }
+}
+
+void sanitize_values32(spx_word32_t *vec, spx_word32_t min_val, spx_word32_t max_val, int len)
+{
+   int i;
+   for (i=0;i<len;i++)
+   {
+      /* It's important we do the test that way so we can catch NaNs, which are neither greater nor smaller */
+      if (!(vec[i]>=min_val && vec[i] <= max_val))
+      {
+         if (vec[i] < min_val)
+            vec[i] = min_val;
+         else if (vec[i] > max_val)
+            vec[i] = max_val;
+         else /* Has to be NaN */
+            vec[i] = 0;
+      }
+   }
+}
+
+void highpass(const spx_word16_t *x, spx_word16_t *y, int len, int filtID, spx_mem_t *mem)
+{
+   int i;
+#ifdef FIXED_POINT
+   const spx_word16_t Pcoef[5][3] = {{16384, -31313, 14991}, {16384, -31569, 15249}, {16384, -31677, 15328}, {16384, -32313, 15947}, {16384, -22446, 6537}};
+   const spx_word16_t Zcoef[5][3] = {{15672, -31344, 15672}, {15802, -31601, 15802}, {15847, -31694, 15847}, {16162, -32322, 16162}, {14418, -28836, 14418}};
+#else
+   const spx_word16_t Pcoef[5][3] = {{1.00000f, -1.91120f, 0.91498f}, {1.00000f, -1.92683f, 0.93071f}, {1.00000f, -1.93338f, 0.93553f}, {1.00000f, -1.97226f, 0.97332f}, {1.00000f, -1.37000f, 0.39900f}};
+   const spx_word16_t Zcoef[5][3] = {{0.95654f, -1.91309f, 0.95654f}, {0.96446f, -1.92879f, 0.96446f}, {0.96723f, -1.93445f, 0.96723f}, {0.98645f, -1.97277f, 0.98645f}, {0.88000f, -1.76000f, 0.88000f}};
+#endif
+   const spx_word16_t *den, *num;
+   if (filtID>4)
+      filtID=4;
+   
+   den = Pcoef[filtID]; num = Zcoef[filtID];
+   /*return;*/
+   for (i=0;i<len;i++)
+   {
+      spx_word16_t yi;
+      spx_word32_t vout = ADD32(MULT16_16(num[0], x[i]),mem[0]);
+      yi = EXTRACT16(SATURATE(PSHR32(vout,14),32767));
+      mem[0] = ADD32(MAC16_16(mem[1], num[1],x[i]), SHL32(MULT16_32_Q15(-den[1],vout),1));
+      mem[1] = ADD32(MULT16_16(num[2],x[i]), SHL32(MULT16_32_Q15(-den[2],vout),1));
+      y[i] = yi;
+   }
+}
+
+#ifdef FIXED_POINT
+
+/* FIXME: These functions are ugly and probably introduce too much error */
+void signal_mul(const spx_sig_t *x, spx_sig_t *y, spx_word32_t scale, int len)
+{
+   int i;
+   for (i=0;i<len;i++)
+   {
+      y[i] = SHL32(MULT16_32_Q14(EXTRACT16(SHR32(x[i],7)),scale),7);
+   }
+}
+
+void signal_div(const spx_word16_t *x, spx_word16_t *y, spx_word32_t scale, int len)
+{
+   int i;
+   if (scale > SHL32(EXTEND32(SIG_SCALING), 8))
+   {
+      spx_word16_t scale_1;
+      scale = PSHR32(scale, SIG_SHIFT);
+      scale_1 = EXTRACT16(PDIV32_16(SHL32(EXTEND32(SIG_SCALING),7),scale));
+      for (i=0;i<len;i++)
+      {
+         y[i] = MULT16_16_P15(scale_1, x[i]);
+      }
+   } else if (scale > SHR32(EXTEND32(SIG_SCALING), 2)) {
+      spx_word16_t scale_1;
+      scale = PSHR32(scale, SIG_SHIFT-5);
+      scale_1 = DIV32_16(SHL32(EXTEND32(SIG_SCALING),3),scale);
+      for (i=0;i<len;i++)
+      {
+         y[i] = PSHR32(MULT16_16(scale_1, SHL16(x[i],2)),8);
+      }
+   } else {
+      spx_word16_t scale_1;
+      scale = PSHR32(scale, SIG_SHIFT-7);
+      if (scale < 5)
+         scale = 5;
+      scale_1 = DIV32_16(SHL32(EXTEND32(SIG_SCALING),3),scale);
+      for (i=0;i<len;i++)
+      {
+         y[i] = PSHR32(MULT16_16(scale_1, SHL16(x[i],2)),6);
+      }
+   }
+}
+
+#else
+
+void signal_mul(const spx_sig_t *x, spx_sig_t *y, spx_word32_t scale, int len)
+{
+   int i;
+   for (i=0;i<len;i++)
+      y[i] = scale*x[i];
+}
+
+void signal_div(const spx_sig_t *x, spx_sig_t *y, spx_word32_t scale, int len)
+{
+   int i;
+   float scale_1 = 1/scale;
+   for (i=0;i<len;i++)
+      y[i] = scale_1*x[i];
+}
+#endif
+
+
+
+#ifdef FIXED_POINT
+
+
+
+spx_word16_t compute_rms(const spx_sig_t *x, int len)
+{
+   int i;
+   spx_word32_t sum=0;
+   spx_sig_t max_val=1;
+   int sig_shift;
+
+   for (i=0;i<len;i++)
+   {
+      spx_sig_t tmp = x[i];
+      if (tmp<0)
+         tmp = -tmp;
+      if (tmp > max_val)
+         max_val = tmp;
+   }
+
+   sig_shift=0;
+   while (max_val>16383)
+   {
+      sig_shift++;
+      max_val >>= 1;
+   }
+
+   for (i=0;i<len;i+=4)
+   {
+      spx_word32_t sum2=0;
+      spx_word16_t tmp;
+      tmp = EXTRACT16(SHR32(x[i],sig_shift));
+      sum2 = MAC16_16(sum2,tmp,tmp);
+      tmp = EXTRACT16(SHR32(x[i+1],sig_shift));
+      sum2 = MAC16_16(sum2,tmp,tmp);
+      tmp = EXTRACT16(SHR32(x[i+2],sig_shift));
+      sum2 = MAC16_16(sum2,tmp,tmp);
+      tmp = EXTRACT16(SHR32(x[i+3],sig_shift));
+      sum2 = MAC16_16(sum2,tmp,tmp);
+      sum = ADD32(sum,SHR32(sum2,6));
+   }
+   
+   return EXTRACT16(PSHR32(SHL32(EXTEND32(spx_sqrt(DIV32(sum,len))),(sig_shift+3)),SIG_SHIFT));
+}
+
+spx_word16_t compute_rms16(const spx_word16_t *x, int len)
+{
+   int i;
+   spx_word16_t max_val=10; 
+
+   for (i=0;i<len;i++)
+   {
+      spx_sig_t tmp = x[i];
+      if (tmp<0)
+         tmp = -tmp;
+      if (tmp > max_val)
+         max_val = tmp;
+   }
+   if (max_val>16383)
+   {
+      spx_word32_t sum=0;
+      for (i=0;i<len;i+=4)
+      {
+         spx_word32_t sum2=0;
+         sum2 = MAC16_16(sum2,SHR16(x[i],1),SHR16(x[i],1));
+         sum2 = MAC16_16(sum2,SHR16(x[i+1],1),SHR16(x[i+1],1));
+         sum2 = MAC16_16(sum2,SHR16(x[i+2],1),SHR16(x[i+2],1));
+         sum2 = MAC16_16(sum2,SHR16(x[i+3],1),SHR16(x[i+3],1));
+         sum = ADD32(sum,SHR32(sum2,6));
+      }
+      return SHL16(spx_sqrt(DIV32(sum,len)),4);
+   } else {
+      spx_word32_t sum=0;
+      int sig_shift=0;
+      if (max_val < 8192)
+         sig_shift=1;
+      if (max_val < 4096)
+         sig_shift=2;
+      if (max_val < 2048)
+         sig_shift=3;
+      for (i=0;i<len;i+=4)
+      {
+         spx_word32_t sum2=0;
+         sum2 = MAC16_16(sum2,SHL16(x[i],sig_shift),SHL16(x[i],sig_shift));
+         sum2 = MAC16_16(sum2,SHL16(x[i+1],sig_shift),SHL16(x[i+1],sig_shift));
+         sum2 = MAC16_16(sum2,SHL16(x[i+2],sig_shift),SHL16(x[i+2],sig_shift));
+         sum2 = MAC16_16(sum2,SHL16(x[i+3],sig_shift),SHL16(x[i+3],sig_shift));
+         sum = ADD32(sum,SHR32(sum2,6));
+      }
+      return SHL16(spx_sqrt(DIV32(sum,len)),3-sig_shift);   
+   }
+}
+
+#ifndef OVERRIDE_NORMALIZE16
+int normalize16(const spx_sig_t *x, spx_word16_t *y, spx_sig_t max_scale, int len)
+{
+   int i;
+   spx_sig_t max_val=1;
+   int sig_shift;
+   
+   for (i=0;i<len;i++)
+   {
+      spx_sig_t tmp = x[i];
+      if (tmp<0)
+         tmp = NEG32(tmp);
+      if (tmp >= max_val)
+         max_val = tmp;
+   }
+
+   sig_shift=0;
+   while (max_val>max_scale)
+   {
+      sig_shift++;
+      max_val >>= 1;
+   }
+
+   for (i=0;i<len;i++)
+      y[i] = EXTRACT16(SHR32(x[i], sig_shift));
+   
+   return sig_shift;
+}
+#endif
+
+#else
+
+spx_word16_t compute_rms(const spx_sig_t *x, int len)
+{
+   int i;
+   float sum=0;
+   for (i=0;i<len;i++)
+   {
+      sum += x[i]*x[i];
+   }
+   return sqrt(.1+sum/len);
+}
+spx_word16_t compute_rms16(const spx_word16_t *x, int len)
+{
+   return compute_rms(x, len);
+}
+#endif
+
+
+
+#ifndef OVERRIDE_FILTER_MEM16
+void filter_mem16(const spx_word16_t *x, const spx_coef_t *num, const spx_coef_t *den, spx_word16_t *y, int N, int ord, spx_mem_t *mem, char *stack)
+{
+   int i,j;
+   spx_word16_t xi,yi,nyi;
+   for (i=0;i<N;i++)
+   {
+      xi= x[i];
+      yi = EXTRACT16(SATURATE(ADD32(EXTEND32(x[i]),PSHR32(mem[0],LPC_SHIFT)),32767));
+      nyi = NEG16(yi);
+      for (j=0;j<ord-1;j++)
+      {
+         mem[j] = MAC16_16(MAC16_16(mem[j+1], num[j],xi), den[j],nyi);
+      }
+      mem[ord-1] = ADD32(MULT16_16(num[ord-1],xi), MULT16_16(den[ord-1],nyi));
+      y[i] = yi;
+   }
+}
+#endif
+
+#ifndef OVERRIDE_IIR_MEM16
+void iir_mem16(const spx_word16_t *x, const spx_coef_t *den, spx_word16_t *y, int N, int ord, spx_mem_t *mem, char *stack)
+{
+   int i,j;
+   spx_word16_t yi,nyi;
+
+   for (i=0;i<N;i++)
+   {
+      yi = EXTRACT16(SATURATE(ADD32(EXTEND32(x[i]),PSHR32(mem[0],LPC_SHIFT)),32767));
+      nyi = NEG16(yi);
+      for (j=0;j<ord-1;j++)
+      {
+         mem[j] = MAC16_16(mem[j+1],den[j],nyi);
+      }
+      mem[ord-1] = MULT16_16(den[ord-1],nyi);
+      y[i] = yi;
+   }
+}
+#endif
+
+#ifndef OVERRIDE_FIR_MEM16
+void fir_mem16(const spx_word16_t *x, const spx_coef_t *num, spx_word16_t *y, int N, int ord, spx_mem_t *mem, char *stack)
+{
+   int i,j;
+   spx_word16_t xi,yi;
+
+   for (i=0;i<N;i++)
+   {
+      xi=x[i];
+      yi = EXTRACT16(SATURATE(ADD32(EXTEND32(x[i]),PSHR32(mem[0],LPC_SHIFT)),32767));
+      for (j=0;j<ord-1;j++)
+      {
+         mem[j] = MAC16_16(mem[j+1], num[j],xi);
+      }
+      mem[ord-1] = MULT16_16(num[ord-1],xi);
+      y[i] = yi;
+   }
+}
+#endif
+
+
+void syn_percep_zero16(const spx_word16_t *xx, const spx_coef_t *ak, const spx_coef_t *awk1, const spx_coef_t *awk2, spx_word16_t *y, int N, int ord, char *stack)
+{
+   int i;
+   VARDECL(spx_mem_t *mem);
+   ALLOC(mem, ord, spx_mem_t);
+   for (i=0;i<ord;i++)
+      mem[i]=0;
+   iir_mem16(xx, ak, y, N, ord, mem, stack);
+   for (i=0;i<ord;i++)
+      mem[i]=0;
+   filter_mem16(y, awk1, awk2, y, N, ord, mem, stack);
+}
+void residue_percep_zero16(const spx_word16_t *xx, const spx_coef_t *ak, const spx_coef_t *awk1, const spx_coef_t *awk2, spx_word16_t *y, int N, int ord, char *stack)
+{
+   int i;
+   VARDECL(spx_mem_t *mem);
+   ALLOC(mem, ord, spx_mem_t);
+   for (i=0;i<ord;i++)
+      mem[i]=0;
+   filter_mem16(xx, ak, awk1, y, N, ord, mem, stack);
+   for (i=0;i<ord;i++)
+      mem[i]=0;
+   fir_mem16(y, awk2, y, N, ord, mem, stack);
+}
+
+
+#ifndef OVERRIDE_COMPUTE_IMPULSE_RESPONSE
+void compute_impulse_response(const spx_coef_t *ak, const spx_coef_t *awk1, const spx_coef_t *awk2, spx_word16_t *y, int N, int ord, char *stack)
+{
+   int i,j;
+   spx_word16_t y1, ny1i, ny2i;
+   VARDECL(spx_mem_t *mem1);
+   VARDECL(spx_mem_t *mem2);
+   ALLOC(mem1, ord, spx_mem_t);
+   ALLOC(mem2, ord, spx_mem_t);
+   
+   y[0] = LPC_SCALING;
+   for (i=0;i<ord;i++)
+      y[i+1] = awk1[i];
+   i++;
+   for (;i<N;i++)
+      y[i] = VERY_SMALL;
+   for (i=0;i<ord;i++)
+      mem1[i] = mem2[i] = 0;
+   for (i=0;i<N;i++)
+   {
+      y1 = ADD16(y[i], EXTRACT16(PSHR32(mem1[0],LPC_SHIFT)));
+      ny1i = NEG16(y1);
+      y[i] = PSHR32(ADD32(SHL32(EXTEND32(y1),LPC_SHIFT+1),mem2[0]),LPC_SHIFT);
+      ny2i = NEG16(y[i]);
+      for (j=0;j<ord-1;j++)
+      {
+         mem1[j] = MAC16_16(mem1[j+1], awk2[j],ny1i);
+         mem2[j] = MAC16_16(mem2[j+1], ak[j],ny2i);
+      }
+      mem1[ord-1] = MULT16_16(awk2[ord-1],ny1i);
+      mem2[ord-1] = MULT16_16(ak[ord-1],ny2i);
+   }
+}
+#endif
+
+/* Decomposes a signal into low-band and high-band using a QMF */
+void qmf_decomp(const spx_word16_t *xx, const spx_word16_t *aa, spx_word16_t *y1, spx_word16_t *y2, int N, int M, spx_word16_t *mem, char *stack)
+{
+   int i,j,k,M2;
+   VARDECL(spx_word16_t *a);
+   VARDECL(spx_word16_t *x);
+   spx_word16_t *x2;
+   
+   ALLOC(a, M, spx_word16_t);
+   ALLOC(x, N+M-1, spx_word16_t);
+   x2=x+M-1;
+   M2=M>>1;
+   for (i=0;i<M;i++)
+      a[M-i-1]= aa[i];
+   for (i=0;i<M-1;i++)
+      x[i]=mem[M-i-2];
+   for (i=0;i<N;i++)
+      x[i+M-1]=SHR16(xx[i],1);
+   for (i=0;i<M-1;i++)
+      mem[i]=SHR16(xx[N-i-1],1);
+   for (i=0,k=0;i<N;i+=2,k++)
+   {
+      spx_word32_t y1k=0, y2k=0;
+      for (j=0;j<M2;j++)
+      {
+         y1k=ADD32(y1k,MULT16_16(a[j],ADD16(x[i+j],x2[i-j])));
+         y2k=SUB32(y2k,MULT16_16(a[j],SUB16(x[i+j],x2[i-j])));
+         j++;
+         y1k=ADD32(y1k,MULT16_16(a[j],ADD16(x[i+j],x2[i-j])));
+         y2k=ADD32(y2k,MULT16_16(a[j],SUB16(x[i+j],x2[i-j])));
+      }
+      y1[k] = EXTRACT16(SATURATE(PSHR32(y1k,15),32767));
+      y2[k] = EXTRACT16(SATURATE(PSHR32(y2k,15),32767));
+   }
+}
+
+/* Re-synthesised a signal from the QMF low-band and high-band signals */
+void qmf_synth(const spx_word16_t *x1, const spx_word16_t *x2, const spx_word16_t *a, spx_word16_t *y, int N, int M, spx_word16_t *mem1, spx_word16_t *mem2, char *stack)
+   /* assumptions:
+      all odd x[i] are zero -- well, actually they are left out of the array now
+      N and M are multiples of 4 */
+{
+   int i, j;
+   int M2, N2;
+   VARDECL(spx_word16_t *xx1);
+   VARDECL(spx_word16_t *xx2);
+   
+   M2 = M>>1;
+   N2 = N>>1;
+   ALLOC(xx1, M2+N2, spx_word16_t);
+   ALLOC(xx2, M2+N2, spx_word16_t);
+
+   for (i = 0; i < N2; i++)
+      xx1[i] = x1[N2-1-i];
+   for (i = 0; i < M2; i++)
+      xx1[N2+i] = mem1[2*i+1];
+   for (i = 0; i < N2; i++)
+      xx2[i] = x2[N2-1-i];
+   for (i = 0; i < M2; i++)
+      xx2[N2+i] = mem2[2*i+1];
+
+   for (i = 0; i < N2; i += 2) {
+      spx_sig_t y0, y1, y2, y3;
+      spx_word16_t x10, x20;
+
+      y0 = y1 = y2 = y3 = 0;
+      x10 = xx1[N2-2-i];
+      x20 = xx2[N2-2-i];
+
+      for (j = 0; j < M2; j += 2) {
+         spx_word16_t x11, x21;
+         spx_word16_t a0, a1;
+
+         a0 = a[2*j];
+         a1 = a[2*j+1];
+         x11 = xx1[N2-1+j-i];
+         x21 = xx2[N2-1+j-i];
+
+#ifdef FIXED_POINT
+         /* We multiply twice by the same coef to avoid overflows */
+         y0 = MAC16_16(MAC16_16(y0, a0, x11), NEG16(a0), x21);
+         y1 = MAC16_16(MAC16_16(y1, a1, x11), a1, x21);
+         y2 = MAC16_16(MAC16_16(y2, a0, x10), NEG16(a0), x20);
+         y3 = MAC16_16(MAC16_16(y3, a1, x10), a1, x20);
+#else
+         y0 = ADD32(y0,MULT16_16(a0, x11-x21));
+         y1 = ADD32(y1,MULT16_16(a1, x11+x21));
+         y2 = ADD32(y2,MULT16_16(a0, x10-x20));
+         y3 = ADD32(y3,MULT16_16(a1, x10+x20));
+#endif
+         a0 = a[2*j+2];
+         a1 = a[2*j+3];
+         x10 = xx1[N2+j-i];
+         x20 = xx2[N2+j-i];
+
+#ifdef FIXED_POINT
+         /* We multiply twice by the same coef to avoid overflows */
+         y0 = MAC16_16(MAC16_16(y0, a0, x10), NEG16(a0), x20);
+         y1 = MAC16_16(MAC16_16(y1, a1, x10), a1, x20);
+         y2 = MAC16_16(MAC16_16(y2, a0, x11), NEG16(a0), x21);
+         y3 = MAC16_16(MAC16_16(y3, a1, x11), a1, x21);
+#else
+         y0 = ADD32(y0,MULT16_16(a0, x10-x20));
+         y1 = ADD32(y1,MULT16_16(a1, x10+x20));
+         y2 = ADD32(y2,MULT16_16(a0, x11-x21));
+         y3 = ADD32(y3,MULT16_16(a1, x11+x21));
+#endif
+      }
+#ifdef FIXED_POINT
+      y[2*i] = EXTRACT16(SATURATE32(PSHR32(y0,15),32767));
+      y[2*i+1] = EXTRACT16(SATURATE32(PSHR32(y1,15),32767));
+      y[2*i+2] = EXTRACT16(SATURATE32(PSHR32(y2,15),32767));
+      y[2*i+3] = EXTRACT16(SATURATE32(PSHR32(y3,15),32767));
+#else
+      /* Normalize up explicitly if we're in float */
+      y[2*i] = 2.f*y0;
+      y[2*i+1] = 2.f*y1;
+      y[2*i+2] = 2.f*y2;
+      y[2*i+3] = 2.f*y3;
+#endif
+   }
+
+   for (i = 0; i < M2; i++)
+      mem1[2*i+1] = xx1[i];
+   for (i = 0; i < M2; i++)
+      mem2[2*i+1] = xx2[i];
+}
+
+#ifdef FIXED_POINT
+#if 0
+const spx_word16_t shift_filt[3][7] = {{-33,    1043,   -4551,   19959,   19959,   -4551,    1043},
+                                 {-98,    1133,   -4425,   29179,    8895,   -2328,     444},
+                                 {444,   -2328,    8895,   29179,   -4425,    1133,     -98}};
+#else
+const spx_word16_t shift_filt[3][7] = {{-390,    1540,   -4993,   20123,   20123,   -4993,    1540},
+                                {-1064,    2817,   -6694,   31589,    6837,    -990,    -209},
+                                 {-209,    -990,    6837,   31589,   -6694,    2817,   -1064}};
+#endif
+#else
+#if 0
+const float shift_filt[3][7] = {{-9.9369e-04, 3.1831e-02, -1.3889e-01, 6.0910e-01, 6.0910e-01, -1.3889e-01, 3.1831e-02},
+                          {-0.0029937, 0.0345613, -0.1350474, 0.8904793, 0.2714479, -0.0710304, 0.0135403},
+                          {0.0135403, -0.0710304, 0.2714479, 0.8904793, -0.1350474, 0.0345613,  -0.0029937}};
+#else
+const float shift_filt[3][7] = {{-0.011915f, 0.046995f, -0.152373f, 0.614108f, 0.614108f, -0.152373f, 0.046995f},
+                          {-0.0324855f, 0.0859768f, -0.2042986f, 0.9640297f, 0.2086420f, -0.0302054f, -0.0063646f},
+                          {-0.0063646f, -0.0302054f, 0.2086420f, 0.9640297f, -0.2042986f, 0.0859768f, -0.0324855f}};
+#endif
+#endif
+
+int interp_pitch(
+spx_word16_t *exc,          /*decoded excitation*/
+spx_word16_t *interp,          /*decoded excitation*/
+int pitch,               /*pitch period*/
+int len
+)
+{
+   int i,j,k;
+   spx_word32_t corr[4][7];
+   spx_word32_t maxcorr;
+   int maxi, maxj;
+   for (i=0;i<7;i++)
+   {
+      corr[0][i] = inner_prod(exc, exc-pitch-3+i, len);
+   }
+   for (i=0;i<3;i++)
+   {
+      for (j=0;j<7;j++)
+      {
+         int i1, i2;
+         spx_word32_t tmp=0;
+         i1 = 3-j;
+         if (i1<0)
+            i1 = 0;
+         i2 = 10-j;
+         if (i2>7)
+            i2 = 7;
+         for (k=i1;k<i2;k++)
+            tmp += MULT16_32_Q15(shift_filt[i][k],corr[0][j+k-3]);
+         corr[i+1][j] = tmp;
+      }
+   }
+   maxi=maxj=0;
+   maxcorr = corr[0][0];
+   for (i=0;i<4;i++)
+   {
+      for (j=0;j<7;j++)
+      {
+         if (corr[i][j] > maxcorr)
+         {
+            maxcorr = corr[i][j];
+            maxi=i;
+            maxj=j;
+         }
+      }
+   }
+   for (i=0;i<len;i++)
+   {
+      spx_word32_t tmp = 0;
+      if (maxi>0)
+      {
+         for (k=0;k<7;k++)
+         {
+            tmp += MULT16_16(exc[i-(pitch-maxj+3)+k-3],shift_filt[maxi-1][k]);
+         }
+      } else {
+         tmp = SHL32(exc[i-(pitch-maxj+3)],15);
+      }
+      interp[i] = PSHR32(tmp,15);
+   }
+   return pitch-maxj+3;
+}
+
+void multicomb(
+spx_word16_t *exc,          /*decoded excitation*/
+spx_word16_t *new_exc,      /*enhanced excitation*/
+spx_coef_t *ak,           /*LPC filter coefs*/
+int p,               /*LPC order*/
+int nsf,             /*sub-frame size*/
+int pitch,           /*pitch period*/
+int max_pitch,
+spx_word16_t  comb_gain,    /*gain of comb filter*/
+char *stack
+)
+{
+   int i; 
+   VARDECL(spx_word16_t *iexc);
+   spx_word16_t old_ener, new_ener;
+   int corr_pitch;
+   
+   spx_word16_t iexc0_mag, iexc1_mag, exc_mag;
+   spx_word32_t corr0, corr1;
+   spx_word16_t gain0, gain1;
+   spx_word16_t pgain1, pgain2;
+   spx_word16_t c1, c2;
+   spx_word16_t g1, g2;
+   spx_word16_t ngain;
+   spx_word16_t gg1, gg2;
+#ifdef FIXED_POINT
+   int scaledown=0;
+#endif
+#if 0 /* Set to 1 to enable full pitch search */
+   int nol_pitch[6];
+   spx_word16_t nol_pitch_coef[6];
+   spx_word16_t ol_pitch_coef;
+   open_loop_nbest_pitch(exc, 20, 120, nsf, 
+                         nol_pitch, nol_pitch_coef, 6, stack);
+   corr_pitch=nol_pitch[0];
+   ol_pitch_coef = nol_pitch_coef[0];
+   /*Try to remove pitch multiples*/
+   for (i=1;i<6;i++)
+   {
+#ifdef FIXED_POINT
+      if ((nol_pitch_coef[i]>MULT16_16_Q15(nol_pitch_coef[0],19661)) && 
+#else
+      if ((nol_pitch_coef[i]>.6*nol_pitch_coef[0]) && 
+#endif
+         (ABS(2*nol_pitch[i]-corr_pitch)<=2 || ABS(3*nol_pitch[i]-corr_pitch)<=3 || 
+         ABS(4*nol_pitch[i]-corr_pitch)<=4 || ABS(5*nol_pitch[i]-corr_pitch)<=5))
+      {
+         corr_pitch = nol_pitch[i];
+      }
+   }
+#else
+   corr_pitch = pitch;
+#endif
+   
+   ALLOC(iexc, 2*nsf, spx_word16_t);
+   
+   interp_pitch(exc, iexc, corr_pitch, 80);
+   if (corr_pitch>max_pitch)
+      interp_pitch(exc, iexc+nsf, 2*corr_pitch, 80);
+   else
+      interp_pitch(exc, iexc+nsf, -corr_pitch, 80);
+
+#ifdef FIXED_POINT
+   for (i=0;i<nsf;i++)
+   {
+      if (ABS16(exc[i])>16383)
+      {
+         scaledown = 1;
+         break;
+      }
+   }
+   if (scaledown)
+   {
+      for (i=0;i<nsf;i++)
+         exc[i] = SHR16(exc[i],1);
+      for (i=0;i<2*nsf;i++)
+         iexc[i] = SHR16(iexc[i],1);
+   }
+#endif
+   /*interp_pitch(exc, iexc+2*nsf, 2*corr_pitch, 80);*/
+   
+   /*printf ("%d %d %f\n", pitch, corr_pitch, max_corr*ener_1);*/
+   iexc0_mag = spx_sqrt(1000+inner_prod(iexc,iexc,nsf));
+   iexc1_mag = spx_sqrt(1000+inner_prod(iexc+nsf,iexc+nsf,nsf));
+   exc_mag = spx_sqrt(1+inner_prod(exc,exc,nsf));
+   corr0  = inner_prod(iexc,exc,nsf);
+   if (corr0<0)
+      corr0=0;
+   corr1 = inner_prod(iexc+nsf,exc,nsf);
+   if (corr1<0)
+      corr1=0;
+#ifdef FIXED_POINT
+   /* Doesn't cost much to limit the ratio and it makes the rest easier */
+   if (SHL32(EXTEND32(iexc0_mag),6) < EXTEND32(exc_mag))
+      iexc0_mag = ADD16(1,PSHR16(exc_mag,6));
+   if (SHL32(EXTEND32(iexc1_mag),6) < EXTEND32(exc_mag))
+      iexc1_mag = ADD16(1,PSHR16(exc_mag,6));
+#endif
+   if (corr0 > MULT16_16(iexc0_mag,exc_mag))
+      pgain1 = QCONST16(1., 14);
+   else
+      pgain1 = PDIV32_16(SHL32(PDIV32(corr0, exc_mag),14),iexc0_mag);
+   if (corr1 > MULT16_16(iexc1_mag,exc_mag))
+      pgain2 = QCONST16(1., 14);
+   else
+      pgain2 = PDIV32_16(SHL32(PDIV32(corr1, exc_mag),14),iexc1_mag);
+   gg1 = PDIV32_16(SHL32(EXTEND32(exc_mag),8), iexc0_mag);
+   gg2 = PDIV32_16(SHL32(EXTEND32(exc_mag),8), iexc1_mag);
+   if (comb_gain>0)
+   {
+#ifdef FIXED_POINT
+      c1 = (MULT16_16_Q15(QCONST16(.4,15),comb_gain)+QCONST16(.07,15));
+      c2 = QCONST16(.5,15)+MULT16_16_Q14(QCONST16(1.72,14),(c1-QCONST16(.07,15)));
+#else
+      c1 = .4*comb_gain+.07;
+      c2 = .5+1.72*(c1-.07);
+#endif
+   } else 
+   {
+      c1=c2=0;
+   }
+#ifdef FIXED_POINT
+   g1 = 32767 - MULT16_16_Q13(MULT16_16_Q15(c2, pgain1),pgain1);
+   g2 = 32767 - MULT16_16_Q13(MULT16_16_Q15(c2, pgain2),pgain2);
+#else
+   g1 = 1-c2*pgain1*pgain1;
+   g2 = 1-c2*pgain2*pgain2;
+#endif
+   if (g1<c1)
+      g1 = c1;
+   if (g2<c1)
+      g2 = c1;
+   g1 = (spx_word16_t)PDIV32_16(SHL32(EXTEND32(c1),14),(spx_word16_t)g1);
+   g2 = (spx_word16_t)PDIV32_16(SHL32(EXTEND32(c1),14),(spx_word16_t)g2);
+   if (corr_pitch>max_pitch)
+   {
+      gain0 = MULT16_16_Q15(QCONST16(.7,15),MULT16_16_Q14(g1,gg1));
+      gain1 = MULT16_16_Q15(QCONST16(.3,15),MULT16_16_Q14(g2,gg2));
+   } else {
+      gain0 = MULT16_16_Q15(QCONST16(.6,15),MULT16_16_Q14(g1,gg1));
+      gain1 = MULT16_16_Q15(QCONST16(.6,15),MULT16_16_Q14(g2,gg2));
+   }
+   for (i=0;i<nsf;i++)
+      new_exc[i] = ADD16(exc[i], EXTRACT16(PSHR32(ADD32(MULT16_16(gain0,iexc[i]), MULT16_16(gain1,iexc[i+nsf])),8)));
+   /* FIXME: compute_rms16 is currently not quite accurate enough (but close) */
+   new_ener = compute_rms16(new_exc, nsf);
+   old_ener = compute_rms16(exc, nsf);
+   
+   if (old_ener < 1)
+      old_ener = 1;
+   if (new_ener < 1)
+      new_ener = 1;
+   if (old_ener > new_ener)
+      old_ener = new_ener;
+   ngain = PDIV32_16(SHL32(EXTEND32(old_ener),14),new_ener);
+   
+   for (i=0;i<nsf;i++)
+      new_exc[i] = MULT16_16_Q14(ngain, new_exc[i]);
+#ifdef FIXED_POINT
+   if (scaledown)
+   {
+      for (i=0;i<nsf;i++)
+         exc[i] = SHL16(exc[i],1);
+      for (i=0;i<nsf;i++)
+         new_exc[i] = SHL16(SATURATE16(new_exc[i],16383),1);
+   }
+#endif
+}
+