gecko-dev/media/libopus/celt/pitch.c
Ralph Giles 41d94ed0c4 Bug 790381 - Update libopus to 1.0.0 release. r=derf
Update files to match the opus-1.0.0 source release.
This corresponds to the spec implementation included
in RFC 6716.

Changes from the previous in-tree version (draft-12):

 - Add extern "C" protection on opus_multistream.h.
 - Align to sizeof(void*) instead of 4 bytes.
 - Copyright header updates for IETF publication.
 - Minor documentation and whitespace fixes.
2012-09-11 13:08:00 -07:00

394 lines
10 KiB
C

/* Copyright (c) 2007-2012 IETF Trust, CSIRO, Xiph.Org Foundation. All rights reserved.
Written by Jean-Marc Valin */
/**
@file pitch.c
@brief Pitch analysis
*/
/*
This file is extracted from RFC6716. Please see that RFC for additional
information.
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 Internet Society, IETF or IETF Trust, nor the
names of specific 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 COPYRIGHT OWNER
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"
#include "celt_lpc.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);
}
}
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};
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;
celt_assert(len>0);
celt_assert(max_pitch>0);
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;
}