mirror of
https://github.com/UberGames/lilium-voyager.git
synced 2024-12-15 06:30:49 +00:00
290 lines
7.8 KiB
C
290 lines
7.8 KiB
C
/* Copyright (c) 2002-2008 Jean-Marc Valin
|
|
Copyright (c) 2007-2008 CSIRO
|
|
Copyright (c) 2007-2009 Xiph.Org Foundation
|
|
Written by Jean-Marc Valin */
|
|
/**
|
|
@file mathops.h
|
|
@brief Various math functions
|
|
*/
|
|
/*
|
|
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 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.
|
|
*/
|
|
|
|
#ifndef MATHOPS_H
|
|
#define MATHOPS_H
|
|
|
|
#include "arch.h"
|
|
#include "entcode.h"
|
|
#include "os_support.h"
|
|
|
|
#define PI 3.141592653f
|
|
|
|
/* Multiplies two 16-bit fractional values. Bit-exactness of this macro is important */
|
|
#define FRAC_MUL16(a,b) ((16384+((opus_int32)(opus_int16)(a)*(opus_int16)(b)))>>15)
|
|
|
|
unsigned isqrt32(opus_uint32 _val);
|
|
|
|
/* CELT doesn't need it for fixed-point, by analysis.c does. */
|
|
#if !defined(FIXED_POINT) || defined(ANALYSIS_C)
|
|
#define cA 0.43157974f
|
|
#define cB 0.67848403f
|
|
#define cC 0.08595542f
|
|
#define cE ((float)PI/2)
|
|
static OPUS_INLINE float fast_atan2f(float y, float x) {
|
|
float x2, y2;
|
|
x2 = x*x;
|
|
y2 = y*y;
|
|
/* For very small values, we don't care about the answer, so
|
|
we can just return 0. */
|
|
if (x2 + y2 < 1e-18f)
|
|
{
|
|
return 0;
|
|
}
|
|
if(x2<y2){
|
|
float den = (y2 + cB*x2) * (y2 + cC*x2);
|
|
return -x*y*(y2 + cA*x2) / den + (y<0 ? -cE : cE);
|
|
}else{
|
|
float den = (x2 + cB*y2) * (x2 + cC*y2);
|
|
return x*y*(x2 + cA*y2) / den + (y<0 ? -cE : cE) - (x*y<0 ? -cE : cE);
|
|
}
|
|
}
|
|
#undef cA
|
|
#undef cB
|
|
#undef cC
|
|
#undef cD
|
|
#endif
|
|
|
|
|
|
#ifndef OVERRIDE_CELT_MAXABS16
|
|
static OPUS_INLINE opus_val32 celt_maxabs16(const opus_val16 *x, int len)
|
|
{
|
|
int i;
|
|
opus_val16 maxval = 0;
|
|
opus_val16 minval = 0;
|
|
for (i=0;i<len;i++)
|
|
{
|
|
maxval = MAX16(maxval, x[i]);
|
|
minval = MIN16(minval, x[i]);
|
|
}
|
|
return MAX32(EXTEND32(maxval),-EXTEND32(minval));
|
|
}
|
|
#endif
|
|
|
|
#ifndef OVERRIDE_CELT_MAXABS32
|
|
#ifdef FIXED_POINT
|
|
static OPUS_INLINE opus_val32 celt_maxabs32(const opus_val32 *x, int len)
|
|
{
|
|
int i;
|
|
opus_val32 maxval = 0;
|
|
opus_val32 minval = 0;
|
|
for (i=0;i<len;i++)
|
|
{
|
|
maxval = MAX32(maxval, x[i]);
|
|
minval = MIN32(minval, x[i]);
|
|
}
|
|
return MAX32(maxval, -minval);
|
|
}
|
|
#else
|
|
#define celt_maxabs32(x,len) celt_maxabs16(x,len)
|
|
#endif
|
|
#endif
|
|
|
|
|
|
#ifndef FIXED_POINT
|
|
|
|
#define celt_sqrt(x) ((float)sqrt(x))
|
|
#define celt_rsqrt(x) (1.f/celt_sqrt(x))
|
|
#define celt_rsqrt_norm(x) (celt_rsqrt(x))
|
|
#define celt_cos_norm(x) ((float)cos((.5f*PI)*(x)))
|
|
#define celt_rcp(x) (1.f/(x))
|
|
#define celt_div(a,b) ((a)/(b))
|
|
#define frac_div32(a,b) ((float)(a)/(b))
|
|
|
|
#ifdef FLOAT_APPROX
|
|
|
|
/* Note: This assumes radix-2 floating point with the exponent at bits 23..30 and an offset of 127
|
|
denorm, +/- inf and NaN are *not* handled */
|
|
|
|
/** Base-2 log approximation (log2(x)). */
|
|
static OPUS_INLINE float celt_log2(float x)
|
|
{
|
|
int integer;
|
|
float frac;
|
|
union {
|
|
float f;
|
|
opus_uint32 i;
|
|
} in;
|
|
in.f = x;
|
|
integer = (in.i>>23)-127;
|
|
in.i -= integer<<23;
|
|
frac = in.f - 1.5f;
|
|
frac = -0.41445418f + frac*(0.95909232f
|
|
+ frac*(-0.33951290f + frac*0.16541097f));
|
|
return 1+integer+frac;
|
|
}
|
|
|
|
/** Base-2 exponential approximation (2^x). */
|
|
static OPUS_INLINE float celt_exp2(float x)
|
|
{
|
|
int integer;
|
|
float frac;
|
|
union {
|
|
float f;
|
|
opus_uint32 i;
|
|
} res;
|
|
integer = floor(x);
|
|
if (integer < -50)
|
|
return 0;
|
|
frac = x-integer;
|
|
/* K0 = 1, K1 = log(2), K2 = 3-4*log(2), K3 = 3*log(2) - 2 */
|
|
res.f = 0.99992522f + frac * (0.69583354f
|
|
+ frac * (0.22606716f + 0.078024523f*frac));
|
|
res.i = (res.i + (integer<<23)) & 0x7fffffff;
|
|
return res.f;
|
|
}
|
|
|
|
#else
|
|
#define celt_log2(x) ((float)(1.442695040888963387*log(x)))
|
|
#define celt_exp2(x) ((float)exp(0.6931471805599453094*(x)))
|
|
#endif
|
|
|
|
#endif
|
|
|
|
#ifdef FIXED_POINT
|
|
|
|
#include "os_support.h"
|
|
|
|
#ifndef OVERRIDE_CELT_ILOG2
|
|
/** Integer log in base2. Undefined for zero and negative numbers */
|
|
static OPUS_INLINE opus_int16 celt_ilog2(opus_int32 x)
|
|
{
|
|
celt_assert2(x>0, "celt_ilog2() only defined for strictly positive numbers");
|
|
return EC_ILOG(x)-1;
|
|
}
|
|
#endif
|
|
|
|
|
|
/** Integer log in base2. Defined for zero, but not for negative numbers */
|
|
static OPUS_INLINE opus_int16 celt_zlog2(opus_val32 x)
|
|
{
|
|
return x <= 0 ? 0 : celt_ilog2(x);
|
|
}
|
|
|
|
opus_val16 celt_rsqrt_norm(opus_val32 x);
|
|
|
|
opus_val32 celt_sqrt(opus_val32 x);
|
|
|
|
opus_val16 celt_cos_norm(opus_val32 x);
|
|
|
|
/** Base-2 logarithm approximation (log2(x)). (Q14 input, Q10 output) */
|
|
static OPUS_INLINE opus_val16 celt_log2(opus_val32 x)
|
|
{
|
|
int i;
|
|
opus_val16 n, frac;
|
|
/* -0.41509302963303146, 0.9609890551383969, -0.31836011537636605,
|
|
0.15530808010959576, -0.08556153059057618 */
|
|
static const opus_val16 C[5] = {-6801+(1<<(13-DB_SHIFT)), 15746, -5217, 2545, -1401};
|
|
if (x==0)
|
|
return -32767;
|
|
i = celt_ilog2(x);
|
|
n = VSHR32(x,i-15)-32768-16384;
|
|
frac = ADD16(C[0], MULT16_16_Q15(n, ADD16(C[1], MULT16_16_Q15(n, ADD16(C[2], MULT16_16_Q15(n, ADD16(C[3], MULT16_16_Q15(n, C[4]))))))));
|
|
return SHL16(i-13,DB_SHIFT)+SHR16(frac,14-DB_SHIFT);
|
|
}
|
|
|
|
/*
|
|
K0 = 1
|
|
K1 = log(2)
|
|
K2 = 3-4*log(2)
|
|
K3 = 3*log(2) - 2
|
|
*/
|
|
#define D0 16383
|
|
#define D1 22804
|
|
#define D2 14819
|
|
#define D3 10204
|
|
|
|
static OPUS_INLINE opus_val32 celt_exp2_frac(opus_val16 x)
|
|
{
|
|
opus_val16 frac;
|
|
frac = SHL16(x, 4);
|
|
return ADD16(D0, MULT16_16_Q15(frac, ADD16(D1, MULT16_16_Q15(frac, ADD16(D2 , MULT16_16_Q15(D3,frac))))));
|
|
}
|
|
/** Base-2 exponential approximation (2^x). (Q10 input, Q16 output) */
|
|
static OPUS_INLINE opus_val32 celt_exp2(opus_val16 x)
|
|
{
|
|
int integer;
|
|
opus_val16 frac;
|
|
integer = SHR16(x,10);
|
|
if (integer>14)
|
|
return 0x7f000000;
|
|
else if (integer < -15)
|
|
return 0;
|
|
frac = celt_exp2_frac(x-SHL16(integer,10));
|
|
return VSHR32(EXTEND32(frac), -integer-2);
|
|
}
|
|
|
|
opus_val32 celt_rcp(opus_val32 x);
|
|
|
|
#define celt_div(a,b) MULT32_32_Q31((opus_val32)(a),celt_rcp(b))
|
|
|
|
opus_val32 frac_div32(opus_val32 a, opus_val32 b);
|
|
|
|
#define M1 32767
|
|
#define M2 -21
|
|
#define M3 -11943
|
|
#define M4 4936
|
|
|
|
/* Atan approximation using a 4th order polynomial. Input is in Q15 format
|
|
and normalized by pi/4. Output is in Q15 format */
|
|
static OPUS_INLINE opus_val16 celt_atan01(opus_val16 x)
|
|
{
|
|
return MULT16_16_P15(x, ADD32(M1, MULT16_16_P15(x, ADD32(M2, MULT16_16_P15(x, ADD32(M3, MULT16_16_P15(M4, x)))))));
|
|
}
|
|
|
|
#undef M1
|
|
#undef M2
|
|
#undef M3
|
|
#undef M4
|
|
|
|
/* atan2() approximation valid for positive input values */
|
|
static OPUS_INLINE opus_val16 celt_atan2p(opus_val16 y, opus_val16 x)
|
|
{
|
|
if (y < x)
|
|
{
|
|
opus_val32 arg;
|
|
arg = celt_div(SHL32(EXTEND32(y),15),x);
|
|
if (arg >= 32767)
|
|
arg = 32767;
|
|
return SHR16(celt_atan01(EXTRACT16(arg)),1);
|
|
} else {
|
|
opus_val32 arg;
|
|
arg = celt_div(SHL32(EXTEND32(x),15),y);
|
|
if (arg >= 32767)
|
|
arg = 32767;
|
|
return 25736-SHR16(celt_atan01(EXTRACT16(arg)),1);
|
|
}
|
|
}
|
|
|
|
#endif /* FIXED_POINT */
|
|
#endif /* MATHOPS_H */
|