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154 lines
4.5 KiB
C
154 lines
4.5 KiB
C
/*
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* Musepack audio compression
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*
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* This library is free software; you can redistribute it and/or
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* modify it under the terms of the GNU Lesser General Public
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* License as published by the Free Software Foundation; either
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* version 2.1 of the License, or (at your option) any later version.
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*
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* This library is distributed in the hope that it will be useful,
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* but WITHOUT ANY WARRANTY; without even the implied warranty of
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
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* Lesser General Public License for more details.
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*
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* You should have received a copy of the GNU Lesser General Public
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* License along with this library; if not, write to the Free Software
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* Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
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*/
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#include <mpc/mpc_types.h>
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typedef union mpc_floatint
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{
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float f;
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mpc_int32_t n;
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} mpc_floatint;
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typedef union mpc_doubleint
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{
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double d;
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mpc_int32_t n[2];
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} mpc_doubleint;
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static mpc_inline mpc_int32_t mpc_lrintf(float fVal)
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{
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mpc_floatint tmp;
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tmp.f = fVal + 0x00FF8000;
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return tmp.n - 0x4B7F8000;
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}
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#define mpc_round32 mpc_lrintf
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#define mpc_nearbyintf mpc_lrintf
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#ifndef M_PI
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# define M_PI 3.1415926535897932384626433832795029 // 4*atan(1)
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# define M_PIl 3.1415926535897932384626433832795029L
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# define M_LN2 0.6931471805599453094172321214581766 // ln(2)
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# define M_LN2l 0.6931471805599453094172321214581766L
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# define M_LN10 2.3025850929940456840179914546843642 // ln 10 */
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# define M_LN10l 2.3025850929940456840179914546843642L
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#endif
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// fast but maybe more inaccurate, use if you need speed
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#if defined(__GNUC__) && !defined(__APPLE__)
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# define SIN(x) sinf ((float)(x))
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# define COS(x) cosf ((float)(x))
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# define ATAN2(x,y) atan2f ((float)(x), (float)(y))
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# define SQRT(x) sqrtf ((float)(x))
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# define LOG(x) logf ((float)(x))
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# define LOG10(x) log10f ((float)(x))
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# define POW(x,y) expf (logf(x) * (y))
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# define POW10(x) expf (M_LN10 * (x))
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# define FLOOR(x) floorf ((float)(x))
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# define IFLOOR(x) (int) floorf ((float)(x))
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# define FABS(x) fabsf ((float)(x))
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#else
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# define SIN(x) (float) sin (x)
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# define COS(x) (float) cos (x)
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# define ATAN2(x,y) (float) atan2 (x, y)
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# define SQRT(x) (float) sqrt (x)
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# define LOG(x) (float) log (x)
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# define LOG10(x) (float) log10 (x)
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# define POW(x,y) (float) pow (x,y)
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# define POW10(x) (float) pow (10., (x))
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# define FLOOR(x) (float) floor (x)
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# define IFLOOR(x) (int) floor (x)
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# define FABS(x) (float) fabs (x)
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#endif
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#define SQRTF(x) SQRT (x)
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#ifdef FAST_MATH
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# define TABSTEP 64
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# define COSF(x) my_cos ((float)(x))
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# define ATAN2F(x,y) my_atan2 ((float)(x), (float)(y))
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# define IFLOORF(x) my_ifloor ((float)(x))
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void Init_FastMath ( void );
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extern const float tabatan2 [] [2];
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extern const float tabcos [] [2];
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extern const float tabsqrt_ex [];
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extern const float tabsqrt_m [] [2];
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static mpc_inline float my_atan2 ( float x, float y )
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{
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float t, ret; int i; mpc_floatint mx, my;
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mx.f = x;
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my.f = y;
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if ( (mx.n & 0x7FFFFFFF) < (my.n & 0x7FFFFFFF) ) {
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i = mpc_round32 (t = TABSTEP * (mx.f / my.f));
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ret = tabatan2 [1*TABSTEP+i][0] + tabatan2 [1*TABSTEP+i][1] * (t-i);
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if ( my.n < 0 )
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ret = (float)(ret - M_PI);
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}
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else if ( mx.n < 0 ) {
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i = mpc_round32 (t = TABSTEP * (my.f / mx.f));
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ret = - M_PI/2 - tabatan2 [1*TABSTEP+i][0] + tabatan2 [1*TABSTEP+i][1] * (i-t);
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}
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else if ( mx.n > 0 ) {
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i = mpc_round32 (t = TABSTEP * (my.f / mx.f));
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ret = + M_PI/2 - tabatan2 [1*TABSTEP+i][0] + tabatan2 [1*TABSTEP+i][1] * (i-t);
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}
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else {
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ret = 0.;
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}
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return ret;
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}
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static mpc_inline float my_cos ( float x )
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{
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float t, ret; int i;
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i = mpc_round32 (t = TABSTEP * x);
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ret = tabcos [13*TABSTEP+i][0] + tabcos [13*TABSTEP+i][1] * (t-i);
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return ret;
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}
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static mpc_inline int my_ifloor ( float x )
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{
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mpc_floatint mx;
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mx.f = (float) (x + (0x0C00000L + 0.500000001));
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return mx.n - 1262485505;
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}
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static mpc_inline float my_sqrt ( float x )
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{
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float ret; int i, ex; mpc_floatint mx;
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mx.f = x;
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ex = mx.n >> 23; // get the exponent
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mx.n = (mx.n & 0x7FFFFF) | 0x42800000; // delete the exponent
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i = mpc_round32 (mx.f); // Integer-part of the mantissa (round ????????????)
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ret = tabsqrt_m [i-TABSTEP][0] + tabsqrt_m [i-TABSTEP][1] * (mx.f-i); // calculate value
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ret *= tabsqrt_ex [ex];
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return ret;
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}
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#else
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# define COSF(x) COS (x)
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# define ATAN2F(x,y) ATAN2 (x,y)
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# define IFLOORF(x) IFLOOR (x)
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#endif
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