374 lines
		
	
	
		
			9.8 KiB
		
	
	
	
		
			C
		
	
	
	
	
	
		
		
			
		
	
	
			374 lines
		
	
	
		
			9.8 KiB
		
	
	
	
		
			C
		
	
	
	
	
	
|  | /* Copyright (c) 2007-2008 CSIRO
 | ||
|  |    Copyright (c) 2007-2009 Xiph.Org Foundation | ||
|  |    Written by Jean-Marc Valin */ | ||
|  | /**
 | ||
|  |    @file pitch.c | ||
|  |    @brief Pitch analysis | ||
|  |  */ | ||
|  | 
 | ||
|  | /*
 | ||
|  |    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. | ||
|  |     | ||
|  |    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
 | ||
|  | 
 | ||
|  | /* Always enable postfilter for Opus */ | ||
|  | #if defined(OPUS_BUILD) && !defined(ENABLE_POSTFILTER)
 | ||
|  | #define ENABLE_POSTFILTER
 | ||
|  | #endif
 | ||
|  | 
 | ||
|  | #include "pitch.h"
 | ||
|  | #include "os_support.h"
 | ||
|  | #include "modes.h"
 | ||
|  | #include "stack_alloc.h"
 | ||
|  | #include "mathops.h"
 | ||
|  | 
 | ||
|  | static void find_best_pitch(celt_word32 *xcorr, celt_word32 maxcorr, celt_word16 *y, | ||
|  |                             int yshift, int len, int max_pitch, int best_pitch[2]) | ||
|  | { | ||
|  |    int i, j; | ||
|  |    celt_word32 Syy=1; | ||
|  |    celt_word16 best_num[2]; | ||
|  |    celt_word32 best_den[2]; | ||
|  | #ifdef FIXED_POINT
 | ||
|  |    int xshift; | ||
|  | 
 | ||
|  |    xshift = celt_ilog2(maxcorr)-14; | ||
|  | #endif
 | ||
|  | 
 | ||
|  |    best_num[0] = -1; | ||
|  |    best_num[1] = -1; | ||
|  |    best_den[0] = 0; | ||
|  |    best_den[1] = 0; | ||
|  |    best_pitch[0] = 0; | ||
|  |    best_pitch[1] = 1; | ||
|  |    for (j=0;j<len;j++) | ||
|  |       Syy = MAC16_16(Syy, y[j],y[j]); | ||
|  |    for (i=0;i<max_pitch;i++) | ||
|  |    { | ||
|  |       if (xcorr[i]>0) | ||
|  |       { | ||
|  |          celt_word16 num; | ||
|  |          celt_word32 xcorr16; | ||
|  |          xcorr16 = EXTRACT16(VSHR32(xcorr[i], xshift)); | ||
|  |          num = MULT16_16_Q15(xcorr16,xcorr16); | ||
|  |          if (MULT16_32_Q15(num,best_den[1]) > MULT16_32_Q15(best_num[1],Syy)) | ||
|  |          { | ||
|  |             if (MULT16_32_Q15(num,best_den[0]) > MULT16_32_Q15(best_num[0],Syy)) | ||
|  |             { | ||
|  |                best_num[1] = best_num[0]; | ||
|  |                best_den[1] = best_den[0]; | ||
|  |                best_pitch[1] = best_pitch[0]; | ||
|  |                best_num[0] = num; | ||
|  |                best_den[0] = Syy; | ||
|  |                best_pitch[0] = i; | ||
|  |             } else { | ||
|  |                best_num[1] = num; | ||
|  |                best_den[1] = Syy; | ||
|  |                best_pitch[1] = i; | ||
|  |             } | ||
|  |          } | ||
|  |       } | ||
|  |       Syy += SHR32(MULT16_16(y[i+len],y[i+len]),yshift) - SHR32(MULT16_16(y[i],y[i]),yshift); | ||
|  |       Syy = MAX32(1, Syy); | ||
|  |    } | ||
|  | } | ||
|  | 
 | ||
|  | #include "plc.h"
 | ||
|  | void pitch_downsample(celt_sig * restrict x[], celt_word16 * restrict x_lp, | ||
|  |       int len, int _C) | ||
|  | { | ||
|  |    int i; | ||
|  |    celt_word32 ac[5]; | ||
|  |    celt_word16 tmp=Q15ONE; | ||
|  |    celt_word16 lpc[4], mem[4]={0,0,0,0}; | ||
|  |    const int C = CHANNELS(_C); | ||
|  |    for (i=1;i<len>>1;i++) | ||
|  |       x_lp[i] = SHR32(HALF32(HALF32(x[0][(2*i-1)]+x[0][(2*i+1)])+x[0][2*i]), SIG_SHIFT+3); | ||
|  |    x_lp[0] = SHR32(HALF32(HALF32(x[0][1])+x[0][0]), SIG_SHIFT+3); | ||
|  |    if (C==2) | ||
|  |    { | ||
|  |       for (i=1;i<len>>1;i++) | ||
|  |          x_lp[i] += SHR32(HALF32(HALF32(x[1][(2*i-1)]+x[1][(2*i+1)])+x[1][2*i]), SIG_SHIFT+3); | ||
|  |       x_lp[0] += SHR32(HALF32(HALF32(x[1][1])+x[1][0]), SIG_SHIFT+3); | ||
|  |    } | ||
|  | 
 | ||
|  |    _celt_autocorr(x_lp, ac, NULL, 0, | ||
|  |                   4, len>>1); | ||
|  | 
 | ||
|  |    /* Noise floor -40 dB */ | ||
|  | #ifdef FIXED_POINT
 | ||
|  |    ac[0] += SHR32(ac[0],13); | ||
|  | #else
 | ||
|  |    ac[0] *= 1.0001f; | ||
|  | #endif
 | ||
|  |    /* Lag windowing */ | ||
|  |    for (i=1;i<=4;i++) | ||
|  |    { | ||
|  |       /*ac[i] *= exp(-.5*(2*M_PI*.002*i)*(2*M_PI*.002*i));*/ | ||
|  | #ifdef FIXED_POINT
 | ||
|  |       ac[i] -= MULT16_32_Q15(2*i*i, ac[i]); | ||
|  | #else
 | ||
|  |       ac[i] -= ac[i]*(.008f*i)*(.008f*i); | ||
|  | #endif
 | ||
|  |    } | ||
|  | 
 | ||
|  |    _celt_lpc(lpc, ac, 4); | ||
|  |    for (i=0;i<4;i++) | ||
|  |    { | ||
|  |       tmp = MULT16_16_Q15(QCONST16(.9f,15), tmp); | ||
|  |       lpc[i] = MULT16_16_Q15(lpc[i], tmp); | ||
|  |    } | ||
|  |    fir(x_lp, lpc, x_lp, len>>1, 4, mem); | ||
|  | 
 | ||
|  |    mem[0]=0; | ||
|  |    lpc[0]=QCONST16(.8f,12); | ||
|  |    fir(x_lp, lpc, x_lp, len>>1, 1, mem); | ||
|  | 
 | ||
|  | } | ||
|  | 
 | ||
|  | void pitch_search(const celt_word16 * restrict x_lp, celt_word16 * restrict y, | ||
|  |                   int len, int max_pitch, int *pitch) | ||
|  | { | ||
|  |    int i, j; | ||
|  |    int lag; | ||
|  |    int best_pitch[2]={0}; | ||
|  |    VARDECL(celt_word16, x_lp4); | ||
|  |    VARDECL(celt_word16, y_lp4); | ||
|  |    VARDECL(celt_word32, xcorr); | ||
|  |    celt_word32 maxcorr=1; | ||
|  |    int offset; | ||
|  |    int shift=0; | ||
|  | 
 | ||
|  |    SAVE_STACK; | ||
|  | 
 | ||
|  |    lag = len+max_pitch; | ||
|  | 
 | ||
|  |    ALLOC(x_lp4, len>>2, celt_word16); | ||
|  |    ALLOC(y_lp4, lag>>2, celt_word16); | ||
|  |    ALLOC(xcorr, max_pitch>>1, celt_word32); | ||
|  | 
 | ||
|  |    /* Downsample by 2 again */ | ||
|  |    for (j=0;j<len>>2;j++) | ||
|  |       x_lp4[j] = x_lp[2*j]; | ||
|  |    for (j=0;j<lag>>2;j++) | ||
|  |       y_lp4[j] = y[2*j]; | ||
|  | 
 | ||
|  | #ifdef FIXED_POINT
 | ||
|  |    shift = celt_ilog2(MAX16(1, MAX16(celt_maxabs16(x_lp4, len>>2), celt_maxabs16(y_lp4, lag>>2))))-11; | ||
|  |    if (shift>0) | ||
|  |    { | ||
|  |       for (j=0;j<len>>2;j++) | ||
|  |          x_lp4[j] = SHR16(x_lp4[j], shift); | ||
|  |       for (j=0;j<lag>>2;j++) | ||
|  |          y_lp4[j] = SHR16(y_lp4[j], shift); | ||
|  |       /* Use double the shift for a MAC */ | ||
|  |       shift *= 2; | ||
|  |    } else { | ||
|  |       shift = 0; | ||
|  |    } | ||
|  | #endif
 | ||
|  | 
 | ||
|  |    /* Coarse search with 4x decimation */ | ||
|  | 
 | ||
|  |    for (i=0;i<max_pitch>>2;i++) | ||
|  |    { | ||
|  |       celt_word32 sum = 0; | ||
|  |       for (j=0;j<len>>2;j++) | ||
|  |          sum = MAC16_16(sum, x_lp4[j],y_lp4[i+j]); | ||
|  |       xcorr[i] = MAX32(-1, sum); | ||
|  |       maxcorr = MAX32(maxcorr, sum); | ||
|  |    } | ||
|  |    find_best_pitch(xcorr, maxcorr, y_lp4, 0, len>>2, max_pitch>>2, best_pitch); | ||
|  | 
 | ||
|  |    /* Finer search with 2x decimation */ | ||
|  |    maxcorr=1; | ||
|  |    for (i=0;i<max_pitch>>1;i++) | ||
|  |    { | ||
|  |       celt_word32 sum=0; | ||
|  |       xcorr[i] = 0; | ||
|  |       if (abs(i-2*best_pitch[0])>2 && abs(i-2*best_pitch[1])>2) | ||
|  |          continue; | ||
|  |       for (j=0;j<len>>1;j++) | ||
|  |          sum += SHR32(MULT16_16(x_lp[j],y[i+j]), shift); | ||
|  |       xcorr[i] = MAX32(-1, sum); | ||
|  |       maxcorr = MAX32(maxcorr, sum); | ||
|  |    } | ||
|  |    find_best_pitch(xcorr, maxcorr, y, shift, len>>1, max_pitch>>1, best_pitch); | ||
|  | 
 | ||
|  |    /* Refine by pseudo-interpolation */ | ||
|  |    if (best_pitch[0]>0 && best_pitch[0]<(max_pitch>>1)-1) | ||
|  |    { | ||
|  |       celt_word32 a, b, c; | ||
|  |       a = xcorr[best_pitch[0]-1]; | ||
|  |       b = xcorr[best_pitch[0]]; | ||
|  |       c = xcorr[best_pitch[0]+1]; | ||
|  |       if ((c-a) > MULT16_32_Q15(QCONST16(.7f,15),b-a)) | ||
|  |          offset = 1; | ||
|  |       else if ((a-c) > MULT16_32_Q15(QCONST16(.7f,15),b-c)) | ||
|  |          offset = -1; | ||
|  |       else  | ||
|  |          offset = 0; | ||
|  |    } else { | ||
|  |       offset = 0; | ||
|  |    } | ||
|  |    *pitch = 2*best_pitch[0]-offset; | ||
|  | 
 | ||
|  |    RESTORE_STACK; | ||
|  | } | ||
|  | 
 | ||
|  | #ifdef ENABLE_POSTFILTER
 | ||
|  | static const int second_check[16] = {0, 0, 3, 2, 3, 2, 5, 2, 3, 2, 3, 2, 5, 2, 3, 2}; | ||
|  | celt_word16 remove_doubling(celt_word16 *x, int maxperiod, int minperiod, | ||
|  |       int N, int *_T0, int prev_period, celt_word16 prev_gain) | ||
|  | { | ||
|  |    int k, i, T, T0; | ||
|  |    celt_word16 g, g0; | ||
|  |    celt_word16 pg; | ||
|  |    celt_word32 xy,xx,yy; | ||
|  |    celt_word32 xcorr[3]; | ||
|  |    celt_word32 best_xy, best_yy; | ||
|  |    int offset; | ||
|  |    int minperiod0; | ||
|  | 
 | ||
|  |    minperiod0 = minperiod; | ||
|  |    maxperiod /= 2; | ||
|  |    minperiod /= 2; | ||
|  |    *_T0 /= 2; | ||
|  |    prev_period /= 2; | ||
|  |    N /= 2; | ||
|  |    x += maxperiod; | ||
|  |    if (*_T0>=maxperiod) | ||
|  |       *_T0=maxperiod-1; | ||
|  | 
 | ||
|  |    T = T0 = *_T0; | ||
|  |    xx=xy=yy=0; | ||
|  |    for (i=0;i<N;i++) | ||
|  |    { | ||
|  |       xy = MAC16_16(xy, x[i], x[i-T0]); | ||
|  |       xx = MAC16_16(xx, x[i], x[i]); | ||
|  |       yy = MAC16_16(yy, x[i-T0],x[i-T0]); | ||
|  |    } | ||
|  |    best_xy = xy; | ||
|  |    best_yy = yy; | ||
|  | #ifdef FIXED_POINT
 | ||
|  |       { | ||
|  |          celt_word32 x2y2; | ||
|  |          int sh, t; | ||
|  |          x2y2 = 1+HALF32(MULT32_32_Q31(xx,yy)); | ||
|  |          sh = celt_ilog2(x2y2)>>1; | ||
|  |          t = VSHR32(x2y2, 2*(sh-7)); | ||
|  |          g = g0 = VSHR32(MULT16_32_Q15(celt_rsqrt_norm(t), xy),sh+1); | ||
|  |       } | ||
|  | #else
 | ||
|  |       g = g0 = xy/sqrt(1+xx*yy); | ||
|  | #endif
 | ||
|  |    /* Look for any pitch at T/k */ | ||
|  |    for (k=2;k<=15;k++) | ||
|  |    { | ||
|  |       int T1, T1b; | ||
|  |       celt_word16 g1; | ||
|  |       celt_word16 cont=0; | ||
|  |       T1 = (2*T0+k)/(2*k); | ||
|  |       if (T1 < minperiod) | ||
|  |          break; | ||
|  |       /* Look for another strong correlation at T1b */ | ||
|  |       if (k==2) | ||
|  |       { | ||
|  |          if (T1+T0>maxperiod) | ||
|  |             T1b = T0; | ||
|  |          else | ||
|  |             T1b = T0+T1; | ||
|  |       } else | ||
|  |       { | ||
|  |          T1b = (2*second_check[k]*T0+k)/(2*k); | ||
|  |       } | ||
|  |       xy=yy=0; | ||
|  |       for (i=0;i<N;i++) | ||
|  |       { | ||
|  |          xy = MAC16_16(xy, x[i], x[i-T1]); | ||
|  |          yy = MAC16_16(yy, x[i-T1], x[i-T1]); | ||
|  | 
 | ||
|  |          xy = MAC16_16(xy, x[i], x[i-T1b]); | ||
|  |          yy = MAC16_16(yy, x[i-T1b], x[i-T1b]); | ||
|  |       } | ||
|  | #ifdef FIXED_POINT
 | ||
|  |       { | ||
|  |          celt_word32 x2y2; | ||
|  |          int sh, t; | ||
|  |          x2y2 = 1+MULT32_32_Q31(xx,yy); | ||
|  |          sh = celt_ilog2(x2y2)>>1; | ||
|  |          t = VSHR32(x2y2, 2*(sh-7)); | ||
|  |          g1 = VSHR32(MULT16_32_Q15(celt_rsqrt_norm(t), xy),sh+1); | ||
|  |       } | ||
|  | #else
 | ||
|  |       g1 = xy/sqrt(1+2.f*xx*1.f*yy); | ||
|  | #endif
 | ||
|  |       if (abs(T1-prev_period)<=1) | ||
|  |          cont = prev_gain; | ||
|  |       else if (abs(T1-prev_period)<=2 && 5*k*k < T0) | ||
|  |          cont = HALF32(prev_gain); | ||
|  |       else | ||
|  |          cont = 0; | ||
|  |       if (g1 > QCONST16(.3f,15) + MULT16_16_Q15(QCONST16(.4f,15),g0)-cont) | ||
|  |       { | ||
|  |          best_xy = xy; | ||
|  |          best_yy = yy; | ||
|  |          T = T1; | ||
|  |          g = g1; | ||
|  |       } | ||
|  |    } | ||
|  |    if (best_yy <= best_xy) | ||
|  |       pg = Q15ONE; | ||
|  |    else | ||
|  |       pg = SHR32(frac_div32(best_xy,best_yy+1),16); | ||
|  | 
 | ||
|  |    for (k=0;k<3;k++) | ||
|  |    { | ||
|  |       int T1 = T+k-1; | ||
|  |       xy = 0; | ||
|  |       for (i=0;i<N;i++) | ||
|  |          xy = MAC16_16(xy, x[i], x[i-T1]); | ||
|  |       xcorr[k] = xy; | ||
|  |    } | ||
|  |    if ((xcorr[2]-xcorr[0]) > MULT16_32_Q15(QCONST16(.7f,15),xcorr[1]-xcorr[0])) | ||
|  |       offset = 1; | ||
|  |    else if ((xcorr[0]-xcorr[2]) > MULT16_32_Q15(QCONST16(.7f,15),xcorr[1]-xcorr[2])) | ||
|  |       offset = -1; | ||
|  |    else | ||
|  |       offset = 0; | ||
|  |    if (pg > g) | ||
|  |       pg = g; | ||
|  |    *_T0 = 2*T+offset; | ||
|  | 
 | ||
|  |    if (*_T0<minperiod0) | ||
|  |       *_T0=minperiod0; | ||
|  |    return pg; | ||
|  | } | ||
|  | 
 | ||
|  | #endif /* ENABLE_POSTFILTER */
 |