1 /*
2 * Various fixed-point math operations
3 *
4 * Copyright (c) 2008 Vladimir Voroshilov
5 *
6 * This file is part of FFmpeg.
7 *
8 * FFmpeg is free software; you can redistribute it and/or
9 * modify it under the terms of the GNU Lesser General Public
10 * License as published by the Free Software Foundation; either
11 * version 2.1 of the License, or (at your option) any later version.
12 *
13 * FFmpeg is distributed in the hope that it will be useful,
14 * but WITHOUT ANY WARRANTY; without even the implied warranty of
15 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
16 * Lesser General Public License for more details.
17 *
18 * You should have received a copy of the GNU Lesser General Public
19 * License along with FFmpeg; if not, write to the Free Software
20 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
21 */
22
23 #include <stdint.h>
24
25 #include "config.h"
26 #include "libavutil/avassert.h"
27 #include "libavutil/intmath.h"
28 #include "mathops.h"
29 #include "celp_math.h"
30
31 #ifdef G729_BITEXACT
32 static const uint16_t exp2a[]=
33 {
34 0, 1435, 2901, 4400, 5931, 7496, 9096, 10730,
35 12400, 14106, 15850, 17632, 19454, 21315, 23216, 25160,
36 27146, 29175, 31249, 33368, 35534, 37747, 40009, 42320,
37 44682, 47095, 49562, 52082, 54657, 57289, 59979, 62727,
38 };
39
40 static const uint16_t exp2b[]=
41 {
42 3, 712, 1424, 2134, 2845, 3557, 4270, 4982,
43 5696, 6409, 7124, 7839, 8554, 9270, 9986, 10704,
44 11421, 12138, 12857, 13576, 14295, 15014, 15734, 16455,
45 17176, 17898, 18620, 19343, 20066, 20790, 21514, 22238,
46 };
47
ff_exp2(uint16_t power)48 int ff_exp2(uint16_t power)
49 {
50 unsigned int result= exp2a[power>>10] + 0x10000;
51
52 av_assert2(power <= 0x7fff);
53
54 result= (result<<3) + ((result*exp2b[(power>>5)&31])>>17);
55 return result + ((result*(power&31)*89)>>22);
56 }
57 #endif
58
59 /**
60 * Table used to compute log2(x)
61 *
62 * tab_log2[i] = (1<<15) * log2(1 + i/32), i=0..32
63 */
64 static const uint16_t tab_log2[33] =
65 {
66 #ifdef G729_BITEXACT
67 0, 1455, 2866, 4236, 5568, 6863, 8124, 9352,
68 10549, 11716, 12855, 13967, 15054, 16117, 17156, 18172,
69 19167, 20142, 21097, 22033, 22951, 23852, 24735, 25603,
70 26455, 27291, 28113, 28922, 29716, 30497, 31266, 32023, 32767,
71 #else
72 4, 1459, 2870, 4240, 5572, 6867, 8127, 9355,
73 10552, 11719, 12858, 13971, 15057, 16120, 17158, 18175,
74 19170, 20145, 21100, 22036, 22954, 23854, 24738, 25605,
75 26457, 27294, 28116, 28924, 29719, 30500, 31269, 32025, 32769,
76 #endif
77 };
78
ff_log2_q15(uint32_t value)79 int ff_log2_q15(uint32_t value)
80 {
81 uint8_t power_int;
82 uint8_t frac_x0;
83 uint16_t frac_dx;
84
85 // Stripping zeros from beginning
86 power_int = av_log2(value);
87 value <<= (31 - power_int);
88
89 // b31 is always non-zero now
90 frac_x0 = (value & 0x7c000000) >> 26; // b26-b31 and [32..63] -> [0..31]
91 frac_dx = (value & 0x03fff800) >> 11;
92
93 value = tab_log2[frac_x0];
94 value += (frac_dx * (tab_log2[frac_x0+1] - tab_log2[frac_x0])) >> 15;
95
96 return (power_int << 15) + value;
97 }
98
ff_dot_product(const int16_t *a, const int16_t *b, int length)99 int64_t ff_dot_product(const int16_t *a, const int16_t *b, int length)
100 {
101 int i;
102 int64_t sum = 0;
103
104 for (i = 0; i < length; i++)
105 sum += MUL16(a[i], b[i]);
106
107 return sum;
108 }
109
ff_dot_productf(const float* a, const float* b, int length)110 float ff_dot_productf(const float* a, const float* b, int length)
111 {
112 float sum = 0;
113 int i;
114
115 for(i=0; i<length; i++)
116 sum += a[i] * b[i];
117
118 return sum;
119 }
120
ff_celp_math_init(CELPMContext *c)121 void ff_celp_math_init(CELPMContext *c)
122 {
123 c->dot_productf = ff_dot_productf;
124
125 #if HAVE_MIPSFPU
126 ff_celp_math_init_mips(c);
127 #endif
128 }
129