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 46885f2ff5a7a7d6a73432d26a6c0ae9147e6b452sergeyu@chromium.org#ifndef FIXED_POINT 47885f2ff5a7a7d6a73432d26a6c0ae9147e6b452sergeyu@chromium.org 48885f2ff5a7a7d6a73432d26a6c0ae9147e6b452sergeyu@chromium.org#define PI 3.141592653f 49885f2ff5a7a7d6a73432d26a6c0ae9147e6b452sergeyu@chromium.org#define celt_sqrt(x) ((float)sqrt(x)) 50885f2ff5a7a7d6a73432d26a6c0ae9147e6b452sergeyu@chromium.org#define celt_rsqrt(x) (1.f/celt_sqrt(x)) 51885f2ff5a7a7d6a73432d26a6c0ae9147e6b452sergeyu@chromium.org#define celt_rsqrt_norm(x) (celt_rsqrt(x)) 52885f2ff5a7a7d6a73432d26a6c0ae9147e6b452sergeyu@chromium.org#define celt_cos_norm(x) ((float)cos((.5f*PI)*(x))) 53885f2ff5a7a7d6a73432d26a6c0ae9147e6b452sergeyu@chromium.org#define celt_rcp(x) (1.f/(x)) 54885f2ff5a7a7d6a73432d26a6c0ae9147e6b452sergeyu@chromium.org#define celt_div(a,b) ((a)/(b)) 55885f2ff5a7a7d6a73432d26a6c0ae9147e6b452sergeyu@chromium.org#define frac_div32(a,b) ((float)(a)/(b)) 56885f2ff5a7a7d6a73432d26a6c0ae9147e6b452sergeyu@chromium.org 57885f2ff5a7a7d6a73432d26a6c0ae9147e6b452sergeyu@chromium.org#ifdef FLOAT_APPROX 58885f2ff5a7a7d6a73432d26a6c0ae9147e6b452sergeyu@chromium.org 59885f2ff5a7a7d6a73432d26a6c0ae9147e6b452sergeyu@chromium.org/* Note: This assumes radix-2 floating point with the exponent at bits 23..30 and an offset of 127 60885f2ff5a7a7d6a73432d26a6c0ae9147e6b452sergeyu@chromium.org denorm, +/- inf and NaN are *not* handled */ 61885f2ff5a7a7d6a73432d26a6c0ae9147e6b452sergeyu@chromium.org 62885f2ff5a7a7d6a73432d26a6c0ae9147e6b452sergeyu@chromium.org/** Base-2 log approximation (log2(x)). */ 63885f2ff5a7a7d6a73432d26a6c0ae9147e6b452sergeyu@chromium.orgstatic inline float celt_log2(float x) 64885f2ff5a7a7d6a73432d26a6c0ae9147e6b452sergeyu@chromium.org{ 65885f2ff5a7a7d6a73432d26a6c0ae9147e6b452sergeyu@chromium.org int integer; 66885f2ff5a7a7d6a73432d26a6c0ae9147e6b452sergeyu@chromium.org float frac; 67885f2ff5a7a7d6a73432d26a6c0ae9147e6b452sergeyu@chromium.org union { 68885f2ff5a7a7d6a73432d26a6c0ae9147e6b452sergeyu@chromium.org float f; 69885f2ff5a7a7d6a73432d26a6c0ae9147e6b452sergeyu@chromium.org opus_uint32 i; 70885f2ff5a7a7d6a73432d26a6c0ae9147e6b452sergeyu@chromium.org } in; 71885f2ff5a7a7d6a73432d26a6c0ae9147e6b452sergeyu@chromium.org in.f = x; 72885f2ff5a7a7d6a73432d26a6c0ae9147e6b452sergeyu@chromium.org integer = (in.i>>23)-127; 73885f2ff5a7a7d6a73432d26a6c0ae9147e6b452sergeyu@chromium.org in.i -= integer<<23; 74885f2ff5a7a7d6a73432d26a6c0ae9147e6b452sergeyu@chromium.org frac = in.f - 1.5f; 75885f2ff5a7a7d6a73432d26a6c0ae9147e6b452sergeyu@chromium.org frac = -0.41445418f + frac*(0.95909232f 76885f2ff5a7a7d6a73432d26a6c0ae9147e6b452sergeyu@chromium.org + frac*(-0.33951290f + frac*0.16541097f)); 77885f2ff5a7a7d6a73432d26a6c0ae9147e6b452sergeyu@chromium.org return 1+integer+frac; 78885f2ff5a7a7d6a73432d26a6c0ae9147e6b452sergeyu@chromium.org} 79885f2ff5a7a7d6a73432d26a6c0ae9147e6b452sergeyu@chromium.org 80885f2ff5a7a7d6a73432d26a6c0ae9147e6b452sergeyu@chromium.org/** Base-2 exponential approximation (2^x). */ 81885f2ff5a7a7d6a73432d26a6c0ae9147e6b452sergeyu@chromium.orgstatic inline float celt_exp2(float x) 82885f2ff5a7a7d6a73432d26a6c0ae9147e6b452sergeyu@chromium.org{ 83885f2ff5a7a7d6a73432d26a6c0ae9147e6b452sergeyu@chromium.org int integer; 84885f2ff5a7a7d6a73432d26a6c0ae9147e6b452sergeyu@chromium.org float frac; 85885f2ff5a7a7d6a73432d26a6c0ae9147e6b452sergeyu@chromium.org union { 86885f2ff5a7a7d6a73432d26a6c0ae9147e6b452sergeyu@chromium.org float f; 87885f2ff5a7a7d6a73432d26a6c0ae9147e6b452sergeyu@chromium.org opus_uint32 i; 88885f2ff5a7a7d6a73432d26a6c0ae9147e6b452sergeyu@chromium.org } res; 89885f2ff5a7a7d6a73432d26a6c0ae9147e6b452sergeyu@chromium.org integer = floor(x); 90885f2ff5a7a7d6a73432d26a6c0ae9147e6b452sergeyu@chromium.org if (integer < -50) 91885f2ff5a7a7d6a73432d26a6c0ae9147e6b452sergeyu@chromium.org return 0; 92885f2ff5a7a7d6a73432d26a6c0ae9147e6b452sergeyu@chromium.org frac = x-integer; 93885f2ff5a7a7d6a73432d26a6c0ae9147e6b452sergeyu@chromium.org /* K0 = 1, K1 = log(2), K2 = 3-4*log(2), K3 = 3*log(2) - 2 */ 94885f2ff5a7a7d6a73432d26a6c0ae9147e6b452sergeyu@chromium.org res.f = 0.99992522f + frac * (0.69583354f 95885f2ff5a7a7d6a73432d26a6c0ae9147e6b452sergeyu@chromium.org + frac * (0.22606716f + 0.078024523f*frac)); 96885f2ff5a7a7d6a73432d26a6c0ae9147e6b452sergeyu@chromium.org res.i = (res.i + (integer<<23)) & 0x7fffffff; 97885f2ff5a7a7d6a73432d26a6c0ae9147e6b452sergeyu@chromium.org return res.f; 98885f2ff5a7a7d6a73432d26a6c0ae9147e6b452sergeyu@chromium.org} 99885f2ff5a7a7d6a73432d26a6c0ae9147e6b452sergeyu@chromium.org 100885f2ff5a7a7d6a73432d26a6c0ae9147e6b452sergeyu@chromium.org#else 101885f2ff5a7a7d6a73432d26a6c0ae9147e6b452sergeyu@chromium.org#define celt_log2(x) ((float)(1.442695040888963387*log(x))) 102885f2ff5a7a7d6a73432d26a6c0ae9147e6b452sergeyu@chromium.org#define celt_exp2(x) ((float)exp(0.6931471805599453094*(x))) 103885f2ff5a7a7d6a73432d26a6c0ae9147e6b452sergeyu@chromium.org#endif 104885f2ff5a7a7d6a73432d26a6c0ae9147e6b452sergeyu@chromium.org 105885f2ff5a7a7d6a73432d26a6c0ae9147e6b452sergeyu@chromium.org#endif 106885f2ff5a7a7d6a73432d26a6c0ae9147e6b452sergeyu@chromium.org 107885f2ff5a7a7d6a73432d26a6c0ae9147e6b452sergeyu@chromium.org#ifdef FIXED_POINT 108885f2ff5a7a7d6a73432d26a6c0ae9147e6b452sergeyu@chromium.org 109885f2ff5a7a7d6a73432d26a6c0ae9147e6b452sergeyu@chromium.org#include "os_support.h" 110885f2ff5a7a7d6a73432d26a6c0ae9147e6b452sergeyu@chromium.org 111885f2ff5a7a7d6a73432d26a6c0ae9147e6b452sergeyu@chromium.org#ifndef OVERRIDE_CELT_ILOG2 112885f2ff5a7a7d6a73432d26a6c0ae9147e6b452sergeyu@chromium.org/** Integer log in base2. Undefined for zero and negative numbers */ 113885f2ff5a7a7d6a73432d26a6c0ae9147e6b452sergeyu@chromium.orgstatic inline opus_int16 celt_ilog2(opus_int32 x) 114885f2ff5a7a7d6a73432d26a6c0ae9147e6b452sergeyu@chromium.org{ 115885f2ff5a7a7d6a73432d26a6c0ae9147e6b452sergeyu@chromium.org celt_assert2(x>0, "celt_ilog2() only defined for strictly positive numbers"); 116885f2ff5a7a7d6a73432d26a6c0ae9147e6b452sergeyu@chromium.org return EC_ILOG(x)-1; 117885f2ff5a7a7d6a73432d26a6c0ae9147e6b452sergeyu@chromium.org} 118885f2ff5a7a7d6a73432d26a6c0ae9147e6b452sergeyu@chromium.org#endif 119885f2ff5a7a7d6a73432d26a6c0ae9147e6b452sergeyu@chromium.org 120885f2ff5a7a7d6a73432d26a6c0ae9147e6b452sergeyu@chromium.org#ifndef OVERRIDE_CELT_MAXABS16 121885f2ff5a7a7d6a73432d26a6c0ae9147e6b452sergeyu@chromium.orgstatic inline opus_val16 celt_maxabs16(opus_val16 *x, int len) 122885f2ff5a7a7d6a73432d26a6c0ae9147e6b452sergeyu@chromium.org{ 123885f2ff5a7a7d6a73432d26a6c0ae9147e6b452sergeyu@chromium.org int i; 124885f2ff5a7a7d6a73432d26a6c0ae9147e6b452sergeyu@chromium.org opus_val16 maxval = 0; 125885f2ff5a7a7d6a73432d26a6c0ae9147e6b452sergeyu@chromium.org for (i=0;i<len;i++) 126885f2ff5a7a7d6a73432d26a6c0ae9147e6b452sergeyu@chromium.org maxval = MAX16(maxval, ABS16(x[i])); 127885f2ff5a7a7d6a73432d26a6c0ae9147e6b452sergeyu@chromium.org return maxval; 128885f2ff5a7a7d6a73432d26a6c0ae9147e6b452sergeyu@chromium.org} 129885f2ff5a7a7d6a73432d26a6c0ae9147e6b452sergeyu@chromium.org#endif 130885f2ff5a7a7d6a73432d26a6c0ae9147e6b452sergeyu@chromium.org 131885f2ff5a7a7d6a73432d26a6c0ae9147e6b452sergeyu@chromium.org#ifndef OVERRIDE_CELT_MAXABS32 132885f2ff5a7a7d6a73432d26a6c0ae9147e6b452sergeyu@chromium.orgstatic inline opus_val32 celt_maxabs32(opus_val32 *x, int len) 133885f2ff5a7a7d6a73432d26a6c0ae9147e6b452sergeyu@chromium.org{ 134885f2ff5a7a7d6a73432d26a6c0ae9147e6b452sergeyu@chromium.org int i; 135885f2ff5a7a7d6a73432d26a6c0ae9147e6b452sergeyu@chromium.org opus_val32 maxval = 0; 136885f2ff5a7a7d6a73432d26a6c0ae9147e6b452sergeyu@chromium.org for (i=0;i<len;i++) 137885f2ff5a7a7d6a73432d26a6c0ae9147e6b452sergeyu@chromium.org maxval = MAX32(maxval, ABS32(x[i])); 138885f2ff5a7a7d6a73432d26a6c0ae9147e6b452sergeyu@chromium.org return maxval; 139885f2ff5a7a7d6a73432d26a6c0ae9147e6b452sergeyu@chromium.org} 140885f2ff5a7a7d6a73432d26a6c0ae9147e6b452sergeyu@chromium.org#endif 141885f2ff5a7a7d6a73432d26a6c0ae9147e6b452sergeyu@chromium.org 142885f2ff5a7a7d6a73432d26a6c0ae9147e6b452sergeyu@chromium.org/** Integer log in base2. Defined for zero, but not for negative numbers */ 143885f2ff5a7a7d6a73432d26a6c0ae9147e6b452sergeyu@chromium.orgstatic inline opus_int16 celt_zlog2(opus_val32 x) 144885f2ff5a7a7d6a73432d26a6c0ae9147e6b452sergeyu@chromium.org{ 145885f2ff5a7a7d6a73432d26a6c0ae9147e6b452sergeyu@chromium.org return x <= 0 ? 0 : celt_ilog2(x); 146885f2ff5a7a7d6a73432d26a6c0ae9147e6b452sergeyu@chromium.org} 147885f2ff5a7a7d6a73432d26a6c0ae9147e6b452sergeyu@chromium.org 148885f2ff5a7a7d6a73432d26a6c0ae9147e6b452sergeyu@chromium.orgopus_val16 celt_rsqrt_norm(opus_val32 x); 149885f2ff5a7a7d6a73432d26a6c0ae9147e6b452sergeyu@chromium.org 150885f2ff5a7a7d6a73432d26a6c0ae9147e6b452sergeyu@chromium.orgopus_val32 celt_sqrt(opus_val32 x); 151885f2ff5a7a7d6a73432d26a6c0ae9147e6b452sergeyu@chromium.org 152885f2ff5a7a7d6a73432d26a6c0ae9147e6b452sergeyu@chromium.orgopus_val16 celt_cos_norm(opus_val32 x); 153885f2ff5a7a7d6a73432d26a6c0ae9147e6b452sergeyu@chromium.org 154885f2ff5a7a7d6a73432d26a6c0ae9147e6b452sergeyu@chromium.orgstatic inline opus_val16 celt_log2(opus_val32 x) 155885f2ff5a7a7d6a73432d26a6c0ae9147e6b452sergeyu@chromium.org{ 156885f2ff5a7a7d6a73432d26a6c0ae9147e6b452sergeyu@chromium.org int i; 157885f2ff5a7a7d6a73432d26a6c0ae9147e6b452sergeyu@chromium.org opus_val16 n, frac; 158885f2ff5a7a7d6a73432d26a6c0ae9147e6b452sergeyu@chromium.org /* -0.41509302963303146, 0.9609890551383969, -0.31836011537636605, 159885f2ff5a7a7d6a73432d26a6c0ae9147e6b452sergeyu@chromium.org 0.15530808010959576, -0.08556153059057618 */ 160885f2ff5a7a7d6a73432d26a6c0ae9147e6b452sergeyu@chromium.org static const opus_val16 C[5] = {-6801+(1<<(13-DB_SHIFT)), 15746, -5217, 2545, -1401}; 161885f2ff5a7a7d6a73432d26a6c0ae9147e6b452sergeyu@chromium.org if (x==0) 162885f2ff5a7a7d6a73432d26a6c0ae9147e6b452sergeyu@chromium.org return -32767; 163885f2ff5a7a7d6a73432d26a6c0ae9147e6b452sergeyu@chromium.org i = celt_ilog2(x); 164885f2ff5a7a7d6a73432d26a6c0ae9147e6b452sergeyu@chromium.org n = VSHR32(x,i-15)-32768-16384; 165885f2ff5a7a7d6a73432d26a6c0ae9147e6b452sergeyu@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])))))))); 166885f2ff5a7a7d6a73432d26a6c0ae9147e6b452sergeyu@chromium.org return SHL16(i-13,DB_SHIFT)+SHR16(frac,14-DB_SHIFT); 167885f2ff5a7a7d6a73432d26a6c0ae9147e6b452sergeyu@chromium.org} 168885f2ff5a7a7d6a73432d26a6c0ae9147e6b452sergeyu@chromium.org 169885f2ff5a7a7d6a73432d26a6c0ae9147e6b452sergeyu@chromium.org/* 170885f2ff5a7a7d6a73432d26a6c0ae9147e6b452sergeyu@chromium.org K0 = 1 171885f2ff5a7a7d6a73432d26a6c0ae9147e6b452sergeyu@chromium.org K1 = log(2) 172885f2ff5a7a7d6a73432d26a6c0ae9147e6b452sergeyu@chromium.org K2 = 3-4*log(2) 173885f2ff5a7a7d6a73432d26a6c0ae9147e6b452sergeyu@chromium.org K3 = 3*log(2) - 2 174885f2ff5a7a7d6a73432d26a6c0ae9147e6b452sergeyu@chromium.org*/ 175885f2ff5a7a7d6a73432d26a6c0ae9147e6b452sergeyu@chromium.org#define D0 16383 176885f2ff5a7a7d6a73432d26a6c0ae9147e6b452sergeyu@chromium.org#define D1 22804 177885f2ff5a7a7d6a73432d26a6c0ae9147e6b452sergeyu@chromium.org#define D2 14819 178885f2ff5a7a7d6a73432d26a6c0ae9147e6b452sergeyu@chromium.org#define D3 10204 179885f2ff5a7a7d6a73432d26a6c0ae9147e6b452sergeyu@chromium.org/** Base-2 exponential approximation (2^x). (Q10 input, Q16 output) */ 180885f2ff5a7a7d6a73432d26a6c0ae9147e6b452sergeyu@chromium.orgstatic inline opus_val32 celt_exp2(opus_val16 x) 181885f2ff5a7a7d6a73432d26a6c0ae9147e6b452sergeyu@chromium.org{ 182885f2ff5a7a7d6a73432d26a6c0ae9147e6b452sergeyu@chromium.org int integer; 183885f2ff5a7a7d6a73432d26a6c0ae9147e6b452sergeyu@chromium.org opus_val16 frac; 184885f2ff5a7a7d6a73432d26a6c0ae9147e6b452sergeyu@chromium.org integer = SHR16(x,10); 185885f2ff5a7a7d6a73432d26a6c0ae9147e6b452sergeyu@chromium.org if (integer>14) 186885f2ff5a7a7d6a73432d26a6c0ae9147e6b452sergeyu@chromium.org return 0x7f000000; 187885f2ff5a7a7d6a73432d26a6c0ae9147e6b452sergeyu@chromium.org else if (integer < -15) 188885f2ff5a7a7d6a73432d26a6c0ae9147e6b452sergeyu@chromium.org return 0; 189885f2ff5a7a7d6a73432d26a6c0ae9147e6b452sergeyu@chromium.org frac = SHL16(x-SHL16(integer,10),4); 190885f2ff5a7a7d6a73432d26a6c0ae9147e6b452sergeyu@chromium.org frac = ADD16(D0, MULT16_16_Q15(frac, ADD16(D1, MULT16_16_Q15(frac, ADD16(D2 , MULT16_16_Q15(D3,frac)))))); 191885f2ff5a7a7d6a73432d26a6c0ae9147e6b452sergeyu@chromium.org return VSHR32(EXTEND32(frac), -integer-2); 192885f2ff5a7a7d6a73432d26a6c0ae9147e6b452sergeyu@chromium.org} 193885f2ff5a7a7d6a73432d26a6c0ae9147e6b452sergeyu@chromium.org 194885f2ff5a7a7d6a73432d26a6c0ae9147e6b452sergeyu@chromium.orgopus_val32 celt_rcp(opus_val32 x); 195885f2ff5a7a7d6a73432d26a6c0ae9147e6b452sergeyu@chromium.org 196885f2ff5a7a7d6a73432d26a6c0ae9147e6b452sergeyu@chromium.org#define celt_div(a,b) MULT32_32_Q31((opus_val32)(a),celt_rcp(b)) 197885f2ff5a7a7d6a73432d26a6c0ae9147e6b452sergeyu@chromium.org 198885f2ff5a7a7d6a73432d26a6c0ae9147e6b452sergeyu@chromium.orgopus_val32 frac_div32(opus_val32 a, opus_val32 b); 199885f2ff5a7a7d6a73432d26a6c0ae9147e6b452sergeyu@chromium.org 200885f2ff5a7a7d6a73432d26a6c0ae9147e6b452sergeyu@chromium.org#define M1 32767 201885f2ff5a7a7d6a73432d26a6c0ae9147e6b452sergeyu@chromium.org#define M2 -21 202885f2ff5a7a7d6a73432d26a6c0ae9147e6b452sergeyu@chromium.org#define M3 -11943 203885f2ff5a7a7d6a73432d26a6c0ae9147e6b452sergeyu@chromium.org#define M4 4936 204885f2ff5a7a7d6a73432d26a6c0ae9147e6b452sergeyu@chromium.org 205885f2ff5a7a7d6a73432d26a6c0ae9147e6b452sergeyu@chromium.org/* Atan approximation using a 4th order polynomial. Input is in Q15 format 206885f2ff5a7a7d6a73432d26a6c0ae9147e6b452sergeyu@chromium.org and normalized by pi/4. Output is in Q15 format */ 207885f2ff5a7a7d6a73432d26a6c0ae9147e6b452sergeyu@chromium.orgstatic inline opus_val16 celt_atan01(opus_val16 x) 208885f2ff5a7a7d6a73432d26a6c0ae9147e6b452sergeyu@chromium.org{ 209885f2ff5a7a7d6a73432d26a6c0ae9147e6b452sergeyu@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))))))); 210885f2ff5a7a7d6a73432d26a6c0ae9147e6b452sergeyu@chromium.org} 211885f2ff5a7a7d6a73432d26a6c0ae9147e6b452sergeyu@chromium.org 212885f2ff5a7a7d6a73432d26a6c0ae9147e6b452sergeyu@chromium.org#undef M1 213885f2ff5a7a7d6a73432d26a6c0ae9147e6b452sergeyu@chromium.org#undef M2 214885f2ff5a7a7d6a73432d26a6c0ae9147e6b452sergeyu@chromium.org#undef M3 215885f2ff5a7a7d6a73432d26a6c0ae9147e6b452sergeyu@chromium.org#undef M4 216885f2ff5a7a7d6a73432d26a6c0ae9147e6b452sergeyu@chromium.org 217885f2ff5a7a7d6a73432d26a6c0ae9147e6b452sergeyu@chromium.org/* atan2() approximation valid for positive input values */ 218885f2ff5a7a7d6a73432d26a6c0ae9147e6b452sergeyu@chromium.orgstatic inline opus_val16 celt_atan2p(opus_val16 y, opus_val16 x) 219885f2ff5a7a7d6a73432d26a6c0ae9147e6b452sergeyu@chromium.org{ 220885f2ff5a7a7d6a73432d26a6c0ae9147e6b452sergeyu@chromium.org if (y < x) 221885f2ff5a7a7d6a73432d26a6c0ae9147e6b452sergeyu@chromium.org { 222885f2ff5a7a7d6a73432d26a6c0ae9147e6b452sergeyu@chromium.org opus_val32 arg; 223885f2ff5a7a7d6a73432d26a6c0ae9147e6b452sergeyu@chromium.org arg = celt_div(SHL32(EXTEND32(y),15),x); 224885f2ff5a7a7d6a73432d26a6c0ae9147e6b452sergeyu@chromium.org if (arg >= 32767) 225885f2ff5a7a7d6a73432d26a6c0ae9147e6b452sergeyu@chromium.org arg = 32767; 226885f2ff5a7a7d6a73432d26a6c0ae9147e6b452sergeyu@chromium.org return SHR16(celt_atan01(EXTRACT16(arg)),1); 227885f2ff5a7a7d6a73432d26a6c0ae9147e6b452sergeyu@chromium.org } else { 228885f2ff5a7a7d6a73432d26a6c0ae9147e6b452sergeyu@chromium.org opus_val32 arg; 229885f2ff5a7a7d6a73432d26a6c0ae9147e6b452sergeyu@chromium.org arg = celt_div(SHL32(EXTEND32(x),15),y); 230885f2ff5a7a7d6a73432d26a6c0ae9147e6b452sergeyu@chromium.org if (arg >= 32767) 231885f2ff5a7a7d6a73432d26a6c0ae9147e6b452sergeyu@chromium.org arg = 32767; 232885f2ff5a7a7d6a73432d26a6c0ae9147e6b452sergeyu@chromium.org return 25736-SHR16(celt_atan01(EXTRACT16(arg)),1); 233885f2ff5a7a7d6a73432d26a6c0ae9147e6b452sergeyu@chromium.org } 234885f2ff5a7a7d6a73432d26a6c0ae9147e6b452sergeyu@chromium.org} 235885f2ff5a7a7d6a73432d26a6c0ae9147e6b452sergeyu@chromium.org 236885f2ff5a7a7d6a73432d26a6c0ae9147e6b452sergeyu@chromium.org#endif /* FIXED_POINT */ 237885f2ff5a7a7d6a73432d26a6c0ae9147e6b452sergeyu@chromium.org#endif /* MATHOPS_H */ 238