yi = EXTRACT16(PSHR32(SATURATE(x[i] + SHL32(mem[0],1),536870911),SIG_SHIFT));      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] = SHL32(EXTEND32(yi),SIG_SHIFT);   }}#elsevoid fir_mem2(const spx_sig_t *x, const spx_coef_t *num, spx_sig_t *y, int N, int ord, spx_mem_t *mem){   int i,j;   spx_word32_t xi,yi;   for (i=0;i<N;i++)   {      xi=SATURATE(x[i],805306368);      yi = xi + SHL32(mem[0],2);      for (j=0;j<ord-1;j++)      {         mem[j] = MAC16_32_Q15(mem[j+1], num[j],xi);      }      mem[ord-1] = MULT16_32_Q15(num[ord-1],xi);      y[i] = SATURATE(yi,805306368);   }}#endif#endifvoid syn_percep_zero(const spx_sig_t *xx, const spx_coef_t *ak, const spx_coef_t *awk1, const spx_coef_t *awk2, spx_sig_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_mem2(xx, ak, y, N, ord, mem);   for (i=0;i<ord;i++)      mem[i]=0;   filter_mem2(y, awk1, awk2, y, N, ord, mem);}void residue_percep_zero(const spx_sig_t *xx, const spx_coef_t *ak, const spx_coef_t *awk1, const spx_coef_t *awk2, spx_sig_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_mem2(xx, ak, awk1, y, N, ord, mem);   for (i=0;i<ord;i++)     mem[i]=0;   fir_mem2(y, awk2, y, N, ord, mem);}#ifndef OVERRIDE_COMPUTE_IMPULSE_RESPONSEvoid 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] = ADD16(SHL16(y1,1), EXTRACT16(PSHR32(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);   }}#endifvoid qmf_decomp(const spx_word16_t *xx, const spx_word16_t *aa, spx_sig_t *y1, spx_sig_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]=SATURATE(PSHR(xx[i],1),16383);   for (i=0,k=0;i<N;i+=2,k++)   {      y1[k]=0;      y2[k]=0;      for (j=0;j<M2;j++)      {         y1[k]=ADD32(y1[k],SHR(MULT16_16(a[j],ADD16(x[i+j],x2[i-j])),1));         y2[k]=SUB32(y2[k],SHR(MULT16_16(a[j],SUB16(x[i+j],x2[i-j])),1));         j++;         y1[k]=ADD32(y1[k],SHR(MULT16_16(a[j],ADD16(x[i+j],x2[i-j])),1));         y2[k]=ADD32(y2[k],SHR(MULT16_16(a[j],SUB16(x[i+j],x2[i-j])),1));      }   }   for (i=0;i<M-1;i++)     mem[i]=SATURATE(PSHR(xx[N-i-1],1),16383);}/* By segher */void fir_mem_up(const spx_sig_t *x, const spx_word16_t *a, spx_sig_t *y, int N, int M, spx_word32_t *mem, 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;   VARDECL(spx_word16_t *xx);      ALLOC(xx, M+N-1, spx_word16_t);   for (i = 0; i < N/2; i++)      xx[2*i] = SHR(x[N/2-1-i],SIG_SHIFT+1);   for (i = 0; i < M - 1; i += 2)      xx[N+i] = mem[i+1];   for (i = 0; i < N; i += 4) {      spx_sig_t y0, y1, y2, y3;      spx_word16_t x0;      y0 = y1 = y2 = y3 = 0;      x0 = xx[N-4-i];      for (j = 0; j < M; j += 4) {         spx_word16_t x1;         spx_word16_t a0, a1;         a0 = a[j];         a1 = a[j+1];         x1 = xx[N-2+j-i];         y0 = ADD32(y0,SHR(MULT16_16(a0, x1),1));         y1 = ADD32(y1,SHR(MULT16_16(a1, x1),1));         y2 = ADD32(y2,SHR(MULT16_16(a0, x0),1));         y3 = ADD32(y3,SHR(MULT16_16(a1, x0),1));         a0 = a[j+2];         a1 = a[j+3];         x0 = xx[N+j-i];         y0 = ADD32(y0,SHR(MULT16_16(a0, x0),1));         y1 = ADD32(y1,SHR(MULT16_16(a1, x0),1));         y2 = ADD32(y2,SHR(MULT16_16(a0, x1),1));         y3 = ADD32(y3,SHR(MULT16_16(a1, x1),1));      }      y[i] = y0;      y[i+1] = y1;      y[i+2] = y2;      y[i+3] = y3;   }   for (i = 0; i < M - 1; i += 2)      mem[i+1] = xx[i];}void comb_filter_mem_init (CombFilterMem *mem){   mem->last_pitch=0;   mem->last_pitch_gain[0]=mem->last_pitch_gain[1]=mem->last_pitch_gain[2]=0;   mem->smooth_gain=1;}#ifdef FIXED_POINT#define COMB_STEP 32767#else#define COMB_STEP 1.0#endifvoid comb_filter(spx_sig_t *exc,          /*decoded excitation*/spx_sig_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*/spx_word16_t *pitch_gain,   /*pitch gain (3-tap)*/spx_word16_t  comb_gain,    /*gain of comb filter*/CombFilterMem *mem){   int i;   spx_word16_t exc_energy=0, new_exc_energy=0;   spx_word16_t gain;   spx_word16_t step;   spx_word16_t fact;   /*Compute excitation amplitude prior to enhancement*/   exc_energy = compute_rms(exc, nsf);   /*for (i=0;i<nsf;i++)     exc_energy+=((float)exc[i])*exc[i];*/   /*Some gain adjustment if pitch is too high or if unvoiced*/#ifdef FIXED_POINT   {      spx_word16_t g = gain_3tap_to_1tap(pitch_gain)+gain_3tap_to_1tap(mem->last_pitch_gain);      if (g > 166)         comb_gain = MULT16_16_Q15(DIV32_16(SHL32(EXTEND32(165),15),g), comb_gain);      if (g < 64)         comb_gain = MULT16_16_Q15(SHL16(g, 9), comb_gain);   }#else   {      float g=0;      g = GAIN_SCALING_1*.5*(gain_3tap_to_1tap(pitch_gain)+gain_3tap_to_1tap(mem->last_pitch_gain));      if (g>1.3)         comb_gain*=1.3/g;      if (g<.5)         comb_gain*=2.*g;   }#endif   step = DIV32(COMB_STEP, nsf);   fact=0;   /*Apply pitch comb-filter (filter out noise between pitch harmonics)*/   for (i=0;i<nsf;i++)   {      spx_word32_t exc1, exc2;      fact = ADD16(fact,step);            exc1 = SHL32(MULT16_32_Q15(SHL16(pitch_gain[0],7),exc[i-pitch+1]) +                 MULT16_32_Q15(SHL16(pitch_gain[1],7),exc[i-pitch]) +                 MULT16_32_Q15(SHL16(pitch_gain[2],7),exc[i-pitch-1]) , 2);      exc2 = SHL32(MULT16_32_Q15(SHL16(mem->last_pitch_gain[0],7),exc[i-mem->last_pitch+1]) +                 MULT16_32_Q15(SHL16(mem->last_pitch_gain[1],7),exc[i-mem->last_pitch]) +                 MULT16_32_Q15(SHL16(mem->last_pitch_gain[2],7),exc[i-mem->last_pitch-1]),2);      new_exc[i] = exc[i] + MULT16_32_Q15(comb_gain, ADD32(MULT16_32_Q15(fact,exc1), MULT16_32_Q15(SUB16(COMB_STEP,fact), exc2)));   }   mem->last_pitch_gain[0] = pitch_gain[0];   mem->last_pitch_gain[1] = pitch_gain[1];   mem->last_pitch_gain[2] = pitch_gain[2];   mem->last_pitch = pitch;   /*Amplitude after enhancement*/   new_exc_energy = compute_rms(new_exc, nsf);   if (exc_energy > new_exc_energy)      exc_energy = new_exc_energy;      gain = DIV32_16(SHL32(EXTEND32(exc_energy),15),ADD16(1,new_exc_energy));#ifdef FIXED_POINT   if (gain < 16384)      gain = 16384;#else   if (gain < .5)      gain=.5;#endif#ifdef FIXED_POINT   for (i=0;i<nsf;i++)   {      mem->smooth_gain = ADD16(MULT16_16_Q15(31457,mem->smooth_gain), MULT16_16_Q15(1311,gain));      new_exc[i] = MULT16_32_Q15(mem->smooth_gain, new_exc[i]);   }#else   for (i=0;i<nsf;i++)   {      mem->smooth_gain = .96*mem->smooth_gain + .04*gain;      new_exc[i] *= mem->smooth_gain;   }#endif}