1885f2ff5a7a7d6a73432d26a6c0ae9147e6b452sergeyu@chromium.org/* Copyright (c) 2002-2008 Jean-Marc Valin 2885f2ff5a7a7d6a73432d26a6c0ae9147e6b452sergeyu@chromium.org Copyright (c) 2007-2008 CSIRO 3885f2ff5a7a7d6a73432d26a6c0ae9147e6b452sergeyu@chromium.org Copyright (c) 2007-2009 Xiph.Org Foundation 4885f2ff5a7a7d6a73432d26a6c0ae9147e6b452sergeyu@chromium.org Written by Jean-Marc Valin */ 5885f2ff5a7a7d6a73432d26a6c0ae9147e6b452sergeyu@chromium.org/** 6885f2ff5a7a7d6a73432d26a6c0ae9147e6b452sergeyu@chromium.org @file mathops.h 7885f2ff5a7a7d6a73432d26a6c0ae9147e6b452sergeyu@chromium.org @brief Various math functions 8885f2ff5a7a7d6a73432d26a6c0ae9147e6b452sergeyu@chromium.org*/ 9885f2ff5a7a7d6a73432d26a6c0ae9147e6b452sergeyu@chromium.org/* 10885f2ff5a7a7d6a73432d26a6c0ae9147e6b452sergeyu@chromium.org Redistribution and use in source and binary forms, with or without 11885f2ff5a7a7d6a73432d26a6c0ae9147e6b452sergeyu@chromium.org modification, are permitted provided that the following conditions 12885f2ff5a7a7d6a73432d26a6c0ae9147e6b452sergeyu@chromium.org are met: 13885f2ff5a7a7d6a73432d26a6c0ae9147e6b452sergeyu@chromium.org 14885f2ff5a7a7d6a73432d26a6c0ae9147e6b452sergeyu@chromium.org - Redistributions of source code must retain the above copyright 15885f2ff5a7a7d6a73432d26a6c0ae9147e6b452sergeyu@chromium.org notice, this list of conditions and the following disclaimer. 16885f2ff5a7a7d6a73432d26a6c0ae9147e6b452sergeyu@chromium.org 17885f2ff5a7a7d6a73432d26a6c0ae9147e6b452sergeyu@chromium.org - Redistributions in binary form must reproduce the above copyright 18885f2ff5a7a7d6a73432d26a6c0ae9147e6b452sergeyu@chromium.org notice, this list of conditions and the following disclaimer in the 19885f2ff5a7a7d6a73432d26a6c0ae9147e6b452sergeyu@chromium.org documentation and/or other materials provided with the distribution. 20885f2ff5a7a7d6a73432d26a6c0ae9147e6b452sergeyu@chromium.org 21885f2ff5a7a7d6a73432d26a6c0ae9147e6b452sergeyu@chromium.org THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS 22885f2ff5a7a7d6a73432d26a6c0ae9147e6b452sergeyu@chromium.org ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT 23885f2ff5a7a7d6a73432d26a6c0ae9147e6b452sergeyu@chromium.org LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR 24885f2ff5a7a7d6a73432d26a6c0ae9147e6b452sergeyu@chromium.org A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER 25885f2ff5a7a7d6a73432d26a6c0ae9147e6b452sergeyu@chromium.org OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, 26885f2ff5a7a7d6a73432d26a6c0ae9147e6b452sergeyu@chromium.org EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, 27885f2ff5a7a7d6a73432d26a6c0ae9147e6b452sergeyu@chromium.org PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR 28885f2ff5a7a7d6a73432d26a6c0ae9147e6b452sergeyu@chromium.org PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF 29885f2ff5a7a7d6a73432d26a6c0ae9147e6b452sergeyu@chromium.org LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING 30885f2ff5a7a7d6a73432d26a6c0ae9147e6b452sergeyu@chromium.org NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS 31885f2ff5a7a7d6a73432d26a6c0ae9147e6b452sergeyu@chromium.org SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. 32885f2ff5a7a7d6a73432d26a6c0ae9147e6b452sergeyu@chromium.org*/ 33885f2ff5a7a7d6a73432d26a6c0ae9147e6b452sergeyu@chromium.org 34885f2ff5a7a7d6a73432d26a6c0ae9147e6b452sergeyu@chromium.org#ifndef MATHOPS_H 35885f2ff5a7a7d6a73432d26a6c0ae9147e6b452sergeyu@chromium.org#define MATHOPS_H 36885f2ff5a7a7d6a73432d26a6c0ae9147e6b452sergeyu@chromium.org 37885f2ff5a7a7d6a73432d26a6c0ae9147e6b452sergeyu@chromium.org#include "arch.h" 38885f2ff5a7a7d6a73432d26a6c0ae9147e6b452sergeyu@chromium.org#include "entcode.h" 39885f2ff5a7a7d6a73432d26a6c0ae9147e6b452sergeyu@chromium.org#include "os_support.h" 40885f2ff5a7a7d6a73432d26a6c0ae9147e6b452sergeyu@chromium.org 41885f2ff5a7a7d6a73432d26a6c0ae9147e6b452sergeyu@chromium.org/* Multiplies two 16-bit fractional values. Bit-exactness of this macro is important */ 42885f2ff5a7a7d6a73432d26a6c0ae9147e6b452sergeyu@chromium.org#define FRAC_MUL16(a,b) ((16384+((opus_int32)(opus_int16)(a)*(opus_int16)(b)))>>15) 43885f2ff5a7a7d6a73432d26a6c0ae9147e6b452sergeyu@chromium.org 44885f2ff5a7a7d6a73432d26a6c0ae9147e6b452sergeyu@chromium.orgunsigned isqrt32(opus_uint32 _val); 45885f2ff5a7a7d6a73432d26a6c0ae9147e6b452sergeyu@chromium.org 46e3ea049fcaee2247e45f0ce793d4313babb4ef69tlegrand@chromium.org#ifndef OVERRIDE_CELT_MAXABS16 473c3902f0ac13428394f14f78f0fab05ef3468d69tlegrand@google.comstatic OPUS_INLINE opus_val32 celt_maxabs16(const opus_val16 *x, int len) 48e3ea049fcaee2247e45f0ce793d4313babb4ef69tlegrand@chromium.org{ 49e3ea049fcaee2247e45f0ce793d4313babb4ef69tlegrand@chromium.org int i; 50e3ea049fcaee2247e45f0ce793d4313babb4ef69tlegrand@chromium.org opus_val16 maxval = 0; 51e3ea049fcaee2247e45f0ce793d4313babb4ef69tlegrand@chromium.org opus_val16 minval = 0; 52e3ea049fcaee2247e45f0ce793d4313babb4ef69tlegrand@chromium.org for (i=0;i<len;i++) 53e3ea049fcaee2247e45f0ce793d4313babb4ef69tlegrand@chromium.org { 54e3ea049fcaee2247e45f0ce793d4313babb4ef69tlegrand@chromium.org maxval = MAX16(maxval, x[i]); 55e3ea049fcaee2247e45f0ce793d4313babb4ef69tlegrand@chromium.org minval = MIN16(minval, x[i]); 56e3ea049fcaee2247e45f0ce793d4313babb4ef69tlegrand@chromium.org } 57e3ea049fcaee2247e45f0ce793d4313babb4ef69tlegrand@chromium.org return MAX32(EXTEND32(maxval),-EXTEND32(minval)); 58e3ea049fcaee2247e45f0ce793d4313babb4ef69tlegrand@chromium.org} 59e3ea049fcaee2247e45f0ce793d4313babb4ef69tlegrand@chromium.org#endif 60e3ea049fcaee2247e45f0ce793d4313babb4ef69tlegrand@chromium.org 61e3ea049fcaee2247e45f0ce793d4313babb4ef69tlegrand@chromium.org#ifndef OVERRIDE_CELT_MAXABS32 62e3ea049fcaee2247e45f0ce793d4313babb4ef69tlegrand@chromium.org#ifdef FIXED_POINT 633c3902f0ac13428394f14f78f0fab05ef3468d69tlegrand@google.comstatic OPUS_INLINE opus_val32 celt_maxabs32(const opus_val32 *x, int len) 64e3ea049fcaee2247e45f0ce793d4313babb4ef69tlegrand@chromium.org{ 65e3ea049fcaee2247e45f0ce793d4313babb4ef69tlegrand@chromium.org int i; 66e3ea049fcaee2247e45f0ce793d4313babb4ef69tlegrand@chromium.org opus_val32 maxval = 0; 67e3ea049fcaee2247e45f0ce793d4313babb4ef69tlegrand@chromium.org opus_val32 minval = 0; 68e3ea049fcaee2247e45f0ce793d4313babb4ef69tlegrand@chromium.org for (i=0;i<len;i++) 69e3ea049fcaee2247e45f0ce793d4313babb4ef69tlegrand@chromium.org { 70e3ea049fcaee2247e45f0ce793d4313babb4ef69tlegrand@chromium.org maxval = MAX32(maxval, x[i]); 71e3ea049fcaee2247e45f0ce793d4313babb4ef69tlegrand@chromium.org minval = MIN32(minval, x[i]); 72e3ea049fcaee2247e45f0ce793d4313babb4ef69tlegrand@chromium.org } 73e3ea049fcaee2247e45f0ce793d4313babb4ef69tlegrand@chromium.org return MAX32(maxval, -minval); 74e3ea049fcaee2247e45f0ce793d4313babb4ef69tlegrand@chromium.org} 75e3ea049fcaee2247e45f0ce793d4313babb4ef69tlegrand@chromium.org#else 76e3ea049fcaee2247e45f0ce793d4313babb4ef69tlegrand@chromium.org#define celt_maxabs32(x,len) celt_maxabs16(x,len) 77e3ea049fcaee2247e45f0ce793d4313babb4ef69tlegrand@chromium.org#endif 78e3ea049fcaee2247e45f0ce793d4313babb4ef69tlegrand@chromium.org#endif 79e3ea049fcaee2247e45f0ce793d4313babb4ef69tlegrand@chromium.org 80e3ea049fcaee2247e45f0ce793d4313babb4ef69tlegrand@chromium.org 81885f2ff5a7a7d6a73432d26a6c0ae9147e6b452sergeyu@chromium.org#ifndef FIXED_POINT 82885f2ff5a7a7d6a73432d26a6c0ae9147e6b452sergeyu@chromium.org 83885f2ff5a7a7d6a73432d26a6c0ae9147e6b452sergeyu@chromium.org#define PI 3.141592653f 84885f2ff5a7a7d6a73432d26a6c0ae9147e6b452sergeyu@chromium.org#define celt_sqrt(x) ((float)sqrt(x)) 85885f2ff5a7a7d6a73432d26a6c0ae9147e6b452sergeyu@chromium.org#define celt_rsqrt(x) (1.f/celt_sqrt(x)) 86885f2ff5a7a7d6a73432d26a6c0ae9147e6b452sergeyu@chromium.org#define celt_rsqrt_norm(x) (celt_rsqrt(x)) 87885f2ff5a7a7d6a73432d26a6c0ae9147e6b452sergeyu@chromium.org#define celt_cos_norm(x) ((float)cos((.5f*PI)*(x))) 88885f2ff5a7a7d6a73432d26a6c0ae9147e6b452sergeyu@chromium.org#define celt_rcp(x) (1.f/(x)) 89885f2ff5a7a7d6a73432d26a6c0ae9147e6b452sergeyu@chromium.org#define celt_div(a,b) ((a)/(b)) 90885f2ff5a7a7d6a73432d26a6c0ae9147e6b452sergeyu@chromium.org#define frac_div32(a,b) ((float)(a)/(b)) 91885f2ff5a7a7d6a73432d26a6c0ae9147e6b452sergeyu@chromium.org 92885f2ff5a7a7d6a73432d26a6c0ae9147e6b452sergeyu@chromium.org#ifdef FLOAT_APPROX 93885f2ff5a7a7d6a73432d26a6c0ae9147e6b452sergeyu@chromium.org 94885f2ff5a7a7d6a73432d26a6c0ae9147e6b452sergeyu@chromium.org/* Note: This assumes radix-2 floating point with the exponent at bits 23..30 and an offset of 127 95885f2ff5a7a7d6a73432d26a6c0ae9147e6b452sergeyu@chromium.org denorm, +/- inf and NaN are *not* handled */ 96885f2ff5a7a7d6a73432d26a6c0ae9147e6b452sergeyu@chromium.org 97885f2ff5a7a7d6a73432d26a6c0ae9147e6b452sergeyu@chromium.org/** Base-2 log approximation (log2(x)). */ 983c3902f0ac13428394f14f78f0fab05ef3468d69tlegrand@google.comstatic OPUS_INLINE float celt_log2(float x) 99885f2ff5a7a7d6a73432d26a6c0ae9147e6b452sergeyu@chromium.org{ 100885f2ff5a7a7d6a73432d26a6c0ae9147e6b452sergeyu@chromium.org int integer; 101885f2ff5a7a7d6a73432d26a6c0ae9147e6b452sergeyu@chromium.org float frac; 102885f2ff5a7a7d6a73432d26a6c0ae9147e6b452sergeyu@chromium.org union { 103885f2ff5a7a7d6a73432d26a6c0ae9147e6b452sergeyu@chromium.org float f; 104885f2ff5a7a7d6a73432d26a6c0ae9147e6b452sergeyu@chromium.org opus_uint32 i; 105885f2ff5a7a7d6a73432d26a6c0ae9147e6b452sergeyu@chromium.org } in; 106885f2ff5a7a7d6a73432d26a6c0ae9147e6b452sergeyu@chromium.org in.f = x; 107885f2ff5a7a7d6a73432d26a6c0ae9147e6b452sergeyu@chromium.org integer = (in.i>>23)-127; 108885f2ff5a7a7d6a73432d26a6c0ae9147e6b452sergeyu@chromium.org in.i -= integer<<23; 109885f2ff5a7a7d6a73432d26a6c0ae9147e6b452sergeyu@chromium.org frac = in.f - 1.5f; 110885f2ff5a7a7d6a73432d26a6c0ae9147e6b452sergeyu@chromium.org frac = -0.41445418f + frac*(0.95909232f 111885f2ff5a7a7d6a73432d26a6c0ae9147e6b452sergeyu@chromium.org + frac*(-0.33951290f + frac*0.16541097f)); 112885f2ff5a7a7d6a73432d26a6c0ae9147e6b452sergeyu@chromium.org return 1+integer+frac; 113885f2ff5a7a7d6a73432d26a6c0ae9147e6b452sergeyu@chromium.org} 114885f2ff5a7a7d6a73432d26a6c0ae9147e6b452sergeyu@chromium.org 115885f2ff5a7a7d6a73432d26a6c0ae9147e6b452sergeyu@chromium.org/** Base-2 exponential approximation (2^x). */ 1163c3902f0ac13428394f14f78f0fab05ef3468d69tlegrand@google.comstatic OPUS_INLINE float celt_exp2(float x) 117885f2ff5a7a7d6a73432d26a6c0ae9147e6b452sergeyu@chromium.org{ 118885f2ff5a7a7d6a73432d26a6c0ae9147e6b452sergeyu@chromium.org int integer; 119885f2ff5a7a7d6a73432d26a6c0ae9147e6b452sergeyu@chromium.org float frac; 120885f2ff5a7a7d6a73432d26a6c0ae9147e6b452sergeyu@chromium.org union { 121885f2ff5a7a7d6a73432d26a6c0ae9147e6b452sergeyu@chromium.org float f; 122885f2ff5a7a7d6a73432d26a6c0ae9147e6b452sergeyu@chromium.org opus_uint32 i; 123885f2ff5a7a7d6a73432d26a6c0ae9147e6b452sergeyu@chromium.org } res; 124885f2ff5a7a7d6a73432d26a6c0ae9147e6b452sergeyu@chromium.org integer = floor(x); 125885f2ff5a7a7d6a73432d26a6c0ae9147e6b452sergeyu@chromium.org if (integer < -50) 126885f2ff5a7a7d6a73432d26a6c0ae9147e6b452sergeyu@chromium.org return 0; 127885f2ff5a7a7d6a73432d26a6c0ae9147e6b452sergeyu@chromium.org frac = x-integer; 128885f2ff5a7a7d6a73432d26a6c0ae9147e6b452sergeyu@chromium.org /* K0 = 1, K1 = log(2), K2 = 3-4*log(2), K3 = 3*log(2) - 2 */ 129885f2ff5a7a7d6a73432d26a6c0ae9147e6b452sergeyu@chromium.org res.f = 0.99992522f + frac * (0.69583354f 130885f2ff5a7a7d6a73432d26a6c0ae9147e6b452sergeyu@chromium.org + frac * (0.22606716f + 0.078024523f*frac)); 131885f2ff5a7a7d6a73432d26a6c0ae9147e6b452sergeyu@chromium.org res.i = (res.i + (integer<<23)) & 0x7fffffff; 132885f2ff5a7a7d6a73432d26a6c0ae9147e6b452sergeyu@chromium.org return res.f; 133885f2ff5a7a7d6a73432d26a6c0ae9147e6b452sergeyu@chromium.org} 134885f2ff5a7a7d6a73432d26a6c0ae9147e6b452sergeyu@chromium.org 135885f2ff5a7a7d6a73432d26a6c0ae9147e6b452sergeyu@chromium.org#else 136885f2ff5a7a7d6a73432d26a6c0ae9147e6b452sergeyu@chromium.org#define celt_log2(x) ((float)(1.442695040888963387*log(x))) 137885f2ff5a7a7d6a73432d26a6c0ae9147e6b452sergeyu@chromium.org#define celt_exp2(x) ((float)exp(0.6931471805599453094*(x))) 138885f2ff5a7a7d6a73432d26a6c0ae9147e6b452sergeyu@chromium.org#endif 139885f2ff5a7a7d6a73432d26a6c0ae9147e6b452sergeyu@chromium.org 140885f2ff5a7a7d6a73432d26a6c0ae9147e6b452sergeyu@chromium.org#endif 141885f2ff5a7a7d6a73432d26a6c0ae9147e6b452sergeyu@chromium.org 142885f2ff5a7a7d6a73432d26a6c0ae9147e6b452sergeyu@chromium.org#ifdef FIXED_POINT 143885f2ff5a7a7d6a73432d26a6c0ae9147e6b452sergeyu@chromium.org 144885f2ff5a7a7d6a73432d26a6c0ae9147e6b452sergeyu@chromium.org#include "os_support.h" 145885f2ff5a7a7d6a73432d26a6c0ae9147e6b452sergeyu@chromium.org 146885f2ff5a7a7d6a73432d26a6c0ae9147e6b452sergeyu@chromium.org#ifndef OVERRIDE_CELT_ILOG2 147885f2ff5a7a7d6a73432d26a6c0ae9147e6b452sergeyu@chromium.org/** Integer log in base2. Undefined for zero and negative numbers */ 1483c3902f0ac13428394f14f78f0fab05ef3468d69tlegrand@google.comstatic OPUS_INLINE opus_int16 celt_ilog2(opus_int32 x) 149885f2ff5a7a7d6a73432d26a6c0ae9147e6b452sergeyu@chromium.org{ 150885f2ff5a7a7d6a73432d26a6c0ae9147e6b452sergeyu@chromium.org celt_assert2(x>0, "celt_ilog2() only defined for strictly positive numbers"); 151885f2ff5a7a7d6a73432d26a6c0ae9147e6b452sergeyu@chromium.org return EC_ILOG(x)-1; 152885f2ff5a7a7d6a73432d26a6c0ae9147e6b452sergeyu@chromium.org} 153885f2ff5a7a7d6a73432d26a6c0ae9147e6b452sergeyu@chromium.org#endif 154885f2ff5a7a7d6a73432d26a6c0ae9147e6b452sergeyu@chromium.org 155885f2ff5a7a7d6a73432d26a6c0ae9147e6b452sergeyu@chromium.org 156885f2ff5a7a7d6a73432d26a6c0ae9147e6b452sergeyu@chromium.org/** Integer log in base2. Defined for zero, but not for negative numbers */ 1573c3902f0ac13428394f14f78f0fab05ef3468d69tlegrand@google.comstatic OPUS_INLINE opus_int16 celt_zlog2(opus_val32 x) 158885f2ff5a7a7d6a73432d26a6c0ae9147e6b452sergeyu@chromium.org{ 159885f2ff5a7a7d6a73432d26a6c0ae9147e6b452sergeyu@chromium.org return x <= 0 ? 0 : celt_ilog2(x); 160885f2ff5a7a7d6a73432d26a6c0ae9147e6b452sergeyu@chromium.org} 161885f2ff5a7a7d6a73432d26a6c0ae9147e6b452sergeyu@chromium.org 162885f2ff5a7a7d6a73432d26a6c0ae9147e6b452sergeyu@chromium.orgopus_val16 celt_rsqrt_norm(opus_val32 x); 163885f2ff5a7a7d6a73432d26a6c0ae9147e6b452sergeyu@chromium.org 164885f2ff5a7a7d6a73432d26a6c0ae9147e6b452sergeyu@chromium.orgopus_val32 celt_sqrt(opus_val32 x); 165885f2ff5a7a7d6a73432d26a6c0ae9147e6b452sergeyu@chromium.org 166885f2ff5a7a7d6a73432d26a6c0ae9147e6b452sergeyu@chromium.orgopus_val16 celt_cos_norm(opus_val32 x); 167885f2ff5a7a7d6a73432d26a6c0ae9147e6b452sergeyu@chromium.org 168e3ea049fcaee2247e45f0ce793d4313babb4ef69tlegrand@chromium.org/** Base-2 logarithm approximation (log2(x)). (Q14 input, Q10 output) */ 1693c3902f0ac13428394f14f78f0fab05ef3468d69tlegrand@google.comstatic OPUS_INLINE opus_val16 celt_log2(opus_val32 x) 170885f2ff5a7a7d6a73432d26a6c0ae9147e6b452sergeyu@chromium.org{ 171885f2ff5a7a7d6a73432d26a6c0ae9147e6b452sergeyu@chromium.org int i; 172885f2ff5a7a7d6a73432d26a6c0ae9147e6b452sergeyu@chromium.org opus_val16 n, frac; 173885f2ff5a7a7d6a73432d26a6c0ae9147e6b452sergeyu@chromium.org /* -0.41509302963303146, 0.9609890551383969, -0.31836011537636605, 174885f2ff5a7a7d6a73432d26a6c0ae9147e6b452sergeyu@chromium.org 0.15530808010959576, -0.08556153059057618 */ 175885f2ff5a7a7d6a73432d26a6c0ae9147e6b452sergeyu@chromium.org static const opus_val16 C[5] = {-6801+(1<<(13-DB_SHIFT)), 15746, -5217, 2545, -1401}; 176885f2ff5a7a7d6a73432d26a6c0ae9147e6b452sergeyu@chromium.org if (x==0) 177885f2ff5a7a7d6a73432d26a6c0ae9147e6b452sergeyu@chromium.org return -32767; 178885f2ff5a7a7d6a73432d26a6c0ae9147e6b452sergeyu@chromium.org i = celt_ilog2(x); 179885f2ff5a7a7d6a73432d26a6c0ae9147e6b452sergeyu@chromium.org n = VSHR32(x,i-15)-32768-16384; 180885f2ff5a7a7d6a73432d26a6c0ae9147e6b452sergeyu@chromium.org 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])))))))); 181885f2ff5a7a7d6a73432d26a6c0ae9147e6b452sergeyu@chromium.org return SHL16(i-13,DB_SHIFT)+SHR16(frac,14-DB_SHIFT); 182885f2ff5a7a7d6a73432d26a6c0ae9147e6b452sergeyu@chromium.org} 183885f2ff5a7a7d6a73432d26a6c0ae9147e6b452sergeyu@chromium.org 184885f2ff5a7a7d6a73432d26a6c0ae9147e6b452sergeyu@chromium.org/* 185885f2ff5a7a7d6a73432d26a6c0ae9147e6b452sergeyu@chromium.org K0 = 1 186885f2ff5a7a7d6a73432d26a6c0ae9147e6b452sergeyu@chromium.org K1 = log(2) 187885f2ff5a7a7d6a73432d26a6c0ae9147e6b452sergeyu@chromium.org K2 = 3-4*log(2) 188885f2ff5a7a7d6a73432d26a6c0ae9147e6b452sergeyu@chromium.org K3 = 3*log(2) - 2 189885f2ff5a7a7d6a73432d26a6c0ae9147e6b452sergeyu@chromium.org*/ 190885f2ff5a7a7d6a73432d26a6c0ae9147e6b452sergeyu@chromium.org#define D0 16383 191885f2ff5a7a7d6a73432d26a6c0ae9147e6b452sergeyu@chromium.org#define D1 22804 192885f2ff5a7a7d6a73432d26a6c0ae9147e6b452sergeyu@chromium.org#define D2 14819 193885f2ff5a7a7d6a73432d26a6c0ae9147e6b452sergeyu@chromium.org#define D3 10204 194e3ea049fcaee2247e45f0ce793d4313babb4ef69tlegrand@chromium.org 1953c3902f0ac13428394f14f78f0fab05ef3468d69tlegrand@google.comstatic OPUS_INLINE opus_val32 celt_exp2_frac(opus_val16 x) 196e3ea049fcaee2247e45f0ce793d4313babb4ef69tlegrand@chromium.org{ 197e3ea049fcaee2247e45f0ce793d4313babb4ef69tlegrand@chromium.org opus_val16 frac; 198e3ea049fcaee2247e45f0ce793d4313babb4ef69tlegrand@chromium.org frac = SHL16(x, 4); 199e3ea049fcaee2247e45f0ce793d4313babb4ef69tlegrand@chromium.org return ADD16(D0, MULT16_16_Q15(frac, ADD16(D1, MULT16_16_Q15(frac, ADD16(D2 , MULT16_16_Q15(D3,frac)))))); 200e3ea049fcaee2247e45f0ce793d4313babb4ef69tlegrand@chromium.org} 201885f2ff5a7a7d6a73432d26a6c0ae9147e6b452sergeyu@chromium.org/** Base-2 exponential approximation (2^x). (Q10 input, Q16 output) */ 2023c3902f0ac13428394f14f78f0fab05ef3468d69tlegrand@google.comstatic OPUS_INLINE opus_val32 celt_exp2(opus_val16 x) 203885f2ff5a7a7d6a73432d26a6c0ae9147e6b452sergeyu@chromium.org{ 204885f2ff5a7a7d6a73432d26a6c0ae9147e6b452sergeyu@chromium.org int integer; 205885f2ff5a7a7d6a73432d26a6c0ae9147e6b452sergeyu@chromium.org opus_val16 frac; 206885f2ff5a7a7d6a73432d26a6c0ae9147e6b452sergeyu@chromium.org integer = SHR16(x,10); 207885f2ff5a7a7d6a73432d26a6c0ae9147e6b452sergeyu@chromium.org if (integer>14) 208885f2ff5a7a7d6a73432d26a6c0ae9147e6b452sergeyu@chromium.org return 0x7f000000; 209885f2ff5a7a7d6a73432d26a6c0ae9147e6b452sergeyu@chromium.org else if (integer < -15) 210885f2ff5a7a7d6a73432d26a6c0ae9147e6b452sergeyu@chromium.org return 0; 211e3ea049fcaee2247e45f0ce793d4313babb4ef69tlegrand@chromium.org frac = celt_exp2_frac(x-SHL16(integer,10)); 212885f2ff5a7a7d6a73432d26a6c0ae9147e6b452sergeyu@chromium.org return VSHR32(EXTEND32(frac), -integer-2); 213885f2ff5a7a7d6a73432d26a6c0ae9147e6b452sergeyu@chromium.org} 214885f2ff5a7a7d6a73432d26a6c0ae9147e6b452sergeyu@chromium.org 215885f2ff5a7a7d6a73432d26a6c0ae9147e6b452sergeyu@chromium.orgopus_val32 celt_rcp(opus_val32 x); 216885f2ff5a7a7d6a73432d26a6c0ae9147e6b452sergeyu@chromium.org 217885f2ff5a7a7d6a73432d26a6c0ae9147e6b452sergeyu@chromium.org#define celt_div(a,b) MULT32_32_Q31((opus_val32)(a),celt_rcp(b)) 218885f2ff5a7a7d6a73432d26a6c0ae9147e6b452sergeyu@chromium.org 219885f2ff5a7a7d6a73432d26a6c0ae9147e6b452sergeyu@chromium.orgopus_val32 frac_div32(opus_val32 a, opus_val32 b); 220885f2ff5a7a7d6a73432d26a6c0ae9147e6b452sergeyu@chromium.org 221885f2ff5a7a7d6a73432d26a6c0ae9147e6b452sergeyu@chromium.org#define M1 32767 222885f2ff5a7a7d6a73432d26a6c0ae9147e6b452sergeyu@chromium.org#define M2 -21 223885f2ff5a7a7d6a73432d26a6c0ae9147e6b452sergeyu@chromium.org#define M3 -11943 224885f2ff5a7a7d6a73432d26a6c0ae9147e6b452sergeyu@chromium.org#define M4 4936 225885f2ff5a7a7d6a73432d26a6c0ae9147e6b452sergeyu@chromium.org 226885f2ff5a7a7d6a73432d26a6c0ae9147e6b452sergeyu@chromium.org/* Atan approximation using a 4th order polynomial. Input is in Q15 format 227885f2ff5a7a7d6a73432d26a6c0ae9147e6b452sergeyu@chromium.org and normalized by pi/4. Output is in Q15 format */ 2283c3902f0ac13428394f14f78f0fab05ef3468d69tlegrand@google.comstatic OPUS_INLINE opus_val16 celt_atan01(opus_val16 x) 229885f2ff5a7a7d6a73432d26a6c0ae9147e6b452sergeyu@chromium.org{ 230885f2ff5a7a7d6a73432d26a6c0ae9147e6b452sergeyu@chromium.org return MULT16_16_P15(x, ADD32(M1, MULT16_16_P15(x, ADD32(M2, MULT16_16_P15(x, ADD32(M3, MULT16_16_P15(M4, x))))))); 231885f2ff5a7a7d6a73432d26a6c0ae9147e6b452sergeyu@chromium.org} 232885f2ff5a7a7d6a73432d26a6c0ae9147e6b452sergeyu@chromium.org 233885f2ff5a7a7d6a73432d26a6c0ae9147e6b452sergeyu@chromium.org#undef M1 234885f2ff5a7a7d6a73432d26a6c0ae9147e6b452sergeyu@chromium.org#undef M2 235885f2ff5a7a7d6a73432d26a6c0ae9147e6b452sergeyu@chromium.org#undef M3 236885f2ff5a7a7d6a73432d26a6c0ae9147e6b452sergeyu@chromium.org#undef M4 237885f2ff5a7a7d6a73432d26a6c0ae9147e6b452sergeyu@chromium.org 238885f2ff5a7a7d6a73432d26a6c0ae9147e6b452sergeyu@chromium.org/* atan2() approximation valid for positive input values */ 2393c3902f0ac13428394f14f78f0fab05ef3468d69tlegrand@google.comstatic OPUS_INLINE opus_val16 celt_atan2p(opus_val16 y, opus_val16 x) 240885f2ff5a7a7d6a73432d26a6c0ae9147e6b452sergeyu@chromium.org{ 241885f2ff5a7a7d6a73432d26a6c0ae9147e6b452sergeyu@chromium.org if (y < x) 242885f2ff5a7a7d6a73432d26a6c0ae9147e6b452sergeyu@chromium.org { 243885f2ff5a7a7d6a73432d26a6c0ae9147e6b452sergeyu@chromium.org opus_val32 arg; 244885f2ff5a7a7d6a73432d26a6c0ae9147e6b452sergeyu@chromium.org arg = celt_div(SHL32(EXTEND32(y),15),x); 245885f2ff5a7a7d6a73432d26a6c0ae9147e6b452sergeyu@chromium.org if (arg >= 32767) 246885f2ff5a7a7d6a73432d26a6c0ae9147e6b452sergeyu@chromium.org arg = 32767; 247885f2ff5a7a7d6a73432d26a6c0ae9147e6b452sergeyu@chromium.org return SHR16(celt_atan01(EXTRACT16(arg)),1); 248885f2ff5a7a7d6a73432d26a6c0ae9147e6b452sergeyu@chromium.org } else { 249885f2ff5a7a7d6a73432d26a6c0ae9147e6b452sergeyu@chromium.org opus_val32 arg; 250885f2ff5a7a7d6a73432d26a6c0ae9147e6b452sergeyu@chromium.org arg = celt_div(SHL32(EXTEND32(x),15),y); 251885f2ff5a7a7d6a73432d26a6c0ae9147e6b452sergeyu@chromium.org if (arg >= 32767) 252885f2ff5a7a7d6a73432d26a6c0ae9147e6b452sergeyu@chromium.org arg = 32767; 253885f2ff5a7a7d6a73432d26a6c0ae9147e6b452sergeyu@chromium.org return 25736-SHR16(celt_atan01(EXTRACT16(arg)),1); 254885f2ff5a7a7d6a73432d26a6c0ae9147e6b452sergeyu@chromium.org } 255885f2ff5a7a7d6a73432d26a6c0ae9147e6b452sergeyu@chromium.org} 256885f2ff5a7a7d6a73432d26a6c0ae9147e6b452sergeyu@chromium.org 257885f2ff5a7a7d6a73432d26a6c0ae9147e6b452sergeyu@chromium.org#endif /* FIXED_POINT */ 258885f2ff5a7a7d6a73432d26a6c0ae9147e6b452sergeyu@chromium.org#endif /* MATHOPS_H */ 259