yading@10: /*
yading@10:  * Various fixed-point math operations
yading@10:  *
yading@10:  * Copyright (c) 2008 Vladimir Voroshilov
yading@10:  *
yading@10:  * This file is part of FFmpeg.
yading@10:  *
yading@10:  * FFmpeg is free software; you can redistribute it and/or
yading@10:  * modify it under the terms of the GNU Lesser General Public
yading@10:  * License as published by the Free Software Foundation; either
yading@10:  * version 2.1 of the License, or (at your option) any later version.
yading@10:  *
yading@10:  * FFmpeg is distributed in the hope that it will be useful,
yading@10:  * but WITHOUT ANY WARRANTY; without even the implied warranty of
yading@10:  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
yading@10:  * Lesser General Public License for more details.
yading@10:  *
yading@10:  * You should have received a copy of the GNU Lesser General Public
yading@10:  * License along with FFmpeg; if not, write to the Free Software
yading@10:  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
yading@10:  */
yading@10: 
yading@10: #include <inttypes.h>
yading@10: #include <limits.h>
yading@10: 
yading@10: #include "libavutil/avassert.h"
yading@10: #include "avcodec.h"
yading@10: #include "mathops.h"
yading@10: #include "celp_math.h"
yading@10: #include "libavutil/common.h"
yading@10: 
yading@10: static const uint16_t exp2a[]=
yading@10: {
yading@10:      0,  1435,  2901,  4400,  5931,  7496,  9096, 10730,
yading@10:  12400, 14106, 15850, 17632, 19454, 21315, 23216, 25160,
yading@10:  27146, 29175, 31249, 33368, 35534, 37747, 40009, 42320,
yading@10:  44682, 47095, 49562, 52082, 54657, 57289, 59979, 62727,
yading@10: };
yading@10: 
yading@10: static const uint16_t exp2b[]=
yading@10: {
yading@10:      3,   712,  1424,  2134,  2845,  3557,  4270,  4982,
yading@10:   5696,  6409,  7124,  7839,  8554,  9270,  9986, 10704,
yading@10:  11421, 12138, 12857, 13576, 14295, 15014, 15734, 16455,
yading@10:  17176, 17898, 18620, 19343, 20066, 20790, 21514, 22238,
yading@10: };
yading@10: 
yading@10: int ff_exp2(uint16_t power)
yading@10: {
yading@10:     unsigned int result= exp2a[power>>10] + 0x10000;
yading@10: 
yading@10:     av_assert2(power <= 0x7fff);
yading@10: 
yading@10:     result= (result<<3) + ((result*exp2b[(power>>5)&31])>>17);
yading@10:     return result + ((result*(power&31)*89)>>22);
yading@10: }
yading@10: 
yading@10: /**
yading@10:  * Table used to compute log2(x)
yading@10:  *
yading@10:  * tab_log2[i] = (1<<15) * log2(1 + i/32), i=0..32
yading@10:  */
yading@10: static const uint16_t tab_log2[33] =
yading@10: {
yading@10: #ifdef G729_BITEXACT
yading@10:       0,   1455,   2866,   4236,   5568,   6863,   8124,   9352,
yading@10:   10549,  11716,  12855,  13967,  15054,  16117,  17156,  18172,
yading@10:   19167,  20142,  21097,  22033,  22951,  23852,  24735,  25603,
yading@10:   26455,  27291,  28113,  28922,  29716,  30497,  31266,  32023,  32767,
yading@10: #else
yading@10:       4,   1459,   2870,   4240,   5572,   6867,   8127,   9355,
yading@10:   10552,  11719,  12858,  13971,  15057,  16120,  17158,  18175,
yading@10:   19170,  20145,  21100,  22036,  22954,  23854,  24738,  25605,
yading@10:   26457,  27294,  28116,  28924,  29719,  30500,  31269,  32025,  32769,
yading@10: #endif
yading@10: };
yading@10: 
yading@10: int ff_log2_q15(uint32_t value)
yading@10: {
yading@10:     uint8_t  power_int;
yading@10:     uint8_t  frac_x0;
yading@10:     uint16_t frac_dx;
yading@10: 
yading@10:     // Stripping zeros from beginning
yading@10:     power_int = av_log2(value);
yading@10:     value <<= (31 - power_int);
yading@10: 
yading@10:     // b31 is always non-zero now
yading@10:     frac_x0 = (value & 0x7c000000) >> 26; // b26-b31 and [32..63] -> [0..31]
yading@10:     frac_dx = (value & 0x03fff800) >> 11;
yading@10: 
yading@10:     value = tab_log2[frac_x0];
yading@10:     value += (frac_dx * (tab_log2[frac_x0+1] - tab_log2[frac_x0])) >> 15;
yading@10: 
yading@10:     return (power_int << 15) + value;
yading@10: }
yading@10: 
yading@10: int64_t ff_dot_product(const int16_t *a, const int16_t *b, int length)
yading@10: {
yading@10:     int i;
yading@10:     int64_t sum = 0;
yading@10: 
yading@10:     for (i = 0; i < length; i++)
yading@10:         sum += MUL16(a[i], b[i]);
yading@10: 
yading@10:     return sum;
yading@10: }
yading@10: 
yading@10: float ff_dot_productf(const float* a, const float* b, int length)
yading@10: {
yading@10:     float sum = 0;
yading@10:     int i;
yading@10: 
yading@10:     for(i=0; i<length; i++)
yading@10:         sum += a[i] * b[i];
yading@10: 
yading@10:     return sum;
yading@10: }
yading@10: 
yading@10: void ff_celp_math_init(CELPMContext *c)
yading@10: {
yading@10:     c->dot_productf   = ff_dot_productf;
yading@10: 
yading@10:     if(HAVE_MIPSFPU)
yading@10:         ff_celp_math_init_mips(c);
yading@10: }