diff options
Diffstat (limited to 'celt/pitch.c')
-rw-r--r-- | celt/pitch.c | 384 |
1 files changed, 384 insertions, 0 deletions
diff --git a/celt/pitch.c b/celt/pitch.c new file mode 100644 index 00000000..f6a97f9b --- /dev/null +++ b/celt/pitch.c @@ -0,0 +1,384 @@ +/* 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 + +#include "pitch.h" +#include "os_support.h" +#include "modes.h" +#include "stack_alloc.h" +#include "mathops.h" + +static void find_best_pitch(opus_val32 *xcorr, opus_val16 *y, int len, + int max_pitch, int *best_pitch +#ifdef FIXED_POINT + , int yshift, opus_val32 maxcorr +#endif + ) +{ + int i, j; + opus_val32 Syy=1; + opus_val16 best_num[2]; + opus_val32 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) + { + opus_val16 num; + opus_val32 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[], opus_val16 * restrict x_lp, + int len, int _C) +{ + int i; + opus_val32 ac[5]; + opus_val16 tmp=Q15ONE; + opus_val16 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); + } + celt_fir(x_lp, lpc, x_lp, len>>1, 4, mem); + + mem[0]=0; + lpc[0]=QCONST16(.8f,12); + celt_fir(x_lp, lpc, x_lp, len>>1, 1, mem); + +} + +void pitch_search(const opus_val16 * restrict x_lp, opus_val16 * restrict y, + int len, int max_pitch, int *pitch) +{ + int i, j; + int lag; + int best_pitch[2]={0,0}; + VARDECL(opus_val16, x_lp4); + VARDECL(opus_val16, y_lp4); + VARDECL(opus_val32, xcorr); +#ifdef FIXED_POINT + opus_val32 maxcorr=1; + int shift=0; +#endif + int offset; + + SAVE_STACK; + + lag = len+max_pitch; + + ALLOC(x_lp4, len>>2, opus_val16); + ALLOC(y_lp4, lag>>2, opus_val16); + ALLOC(xcorr, max_pitch>>1, opus_val32); + + /* 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++) + { + opus_val32 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); +#ifdef FIXED_POINT + maxcorr = MAX32(maxcorr, sum); +#endif + } + find_best_pitch(xcorr, y_lp4, len>>2, max_pitch>>2, best_pitch +#ifdef FIXED_POINT + , 0, maxcorr +#endif + ); + + /* Finer search with 2x decimation */ +#ifdef FIXED_POINT + maxcorr=1; +#endif + for (i=0;i<max_pitch>>1;i++) + { + opus_val32 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); +#ifdef FIXED_POINT + maxcorr = MAX32(maxcorr, sum); +#endif + } + find_best_pitch(xcorr, y, len>>1, max_pitch>>1, best_pitch +#ifdef FIXED_POINT + , shift, maxcorr +#endif + ); + + /* Refine by pseudo-interpolation */ + if (best_pitch[0]>0 && best_pitch[0]<(max_pitch>>1)-1) + { + opus_val32 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; +} + +static const int second_check[16] = {0, 0, 3, 2, 3, 2, 5, 2, 3, 2, 3, 2, 5, 2, 3, 2}; +opus_val16 remove_doubling(opus_val16 *x, int maxperiod, int minperiod, + int N, int *_T0, int prev_period, opus_val16 prev_gain) +{ + int k, i, T, T0; + opus_val16 g, g0; + opus_val16 pg; + opus_val32 xy,xx,yy; + opus_val32 xcorr[3]; + opus_val32 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 + { + opus_val32 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/celt_sqrt(1+xx*yy); +#endif + /* Look for any pitch at T/k */ + for (k=2;k<=15;k++) + { + int T1, T1b; + opus_val16 g1; + opus_val16 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 + { + opus_val32 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/celt_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; +} |