Remove unused code under G729_BITEXACT #ifdef.
[libav.git] / libavcodec / celp_math.c
1 /*
2 * Various fixed-point math operations
3 *
4 * Copyright (c) 2008 Vladimir Voroshilov
5 *
6 * This file is part of Libav.
7 *
8 * Libav 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 * Libav 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 Libav; if not, write to the Free Software
20 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
21 */
22
23 #include <inttypes.h>
24 #include <limits.h>
25 #include <assert.h>
26
27 #include "avcodec.h"
28 #include "celp_math.h"
29
30 /**
31 * Cosine table: base_cos[i] = (1<<15) * cos(i*PI/64)
32 */
33 static const int16_t tab_cos[65] =
34 {
35 32767, 32738, 32617, 32421, 32145, 31793, 31364, 30860,
36 30280, 29629, 28905, 28113, 27252, 26326, 25336, 24285,
37 23176, 22011, 20793, 19525, 18210, 16851, 15451, 14014,
38 12543, 11043, 9515, 7965, 6395, 4810, 3214, 1609,
39 1, -1607, -3211, -4808, -6393, -7962, -9513, -11040,
40 -12541, -14012, -15449, -16848, -18207, -19523, -20791, -22009,
41 -23174, -24283, -25334, -26324, -27250, -28111, -28904, -29627,
42 -30279, -30858, -31363, -31792, -32144, -32419, -32616, -32736, -32768,
43 };
44
45 static const uint16_t exp2a[]=
46 {
47 0, 1435, 2901, 4400, 5931, 7496, 9096, 10730,
48 12400, 14106, 15850, 17632, 19454, 21315, 23216, 25160,
49 27146, 29175, 31249, 33368, 35534, 37747, 40009, 42320,
50 44682, 47095, 49562, 52082, 54657, 57289, 59979, 62727,
51 };
52
53 static const uint16_t exp2b[]=
54 {
55 3, 712, 1424, 2134, 2845, 3557, 4270, 4982,
56 5696, 6409, 7124, 7839, 8554, 9270, 9986, 10704,
57 11421, 12138, 12857, 13576, 14295, 15014, 15734, 16455,
58 17176, 17898, 18620, 19343, 20066, 20790, 21514, 22238,
59 };
60
61 int16_t ff_cos(uint16_t arg)
62 {
63 uint8_t offset= arg;
64 uint8_t ind = arg >> 8;
65
66 assert(arg <= 0x3fff);
67
68 return tab_cos[ind] + (offset * (tab_cos[ind+1] - tab_cos[ind]) >> 8);
69 }
70
71 int ff_exp2(uint16_t power)
72 {
73 unsigned int result= exp2a[power>>10] + 0x10000;
74
75 assert(power <= 0x7fff);
76
77 result= (result<<3) + ((result*exp2b[(power>>5)&31])>>17);
78 return result + ((result*(power&31)*89)>>22);
79 }
80
81 /**
82 * Table used to compute log2(x)
83 *
84 * tab_log2[i] = (1<<15) * log2(1 + i/32), i=0..32
85 */
86 static const uint16_t tab_log2[33] =
87 {
88 4, 1459, 2870, 4240, 5572, 6867, 8127, 9355,
89 10552, 11719, 12858, 13971, 15057, 16120, 17158, 18175,
90 19170, 20145, 21100, 22036, 22954, 23854, 24738, 25605,
91 26457, 27294, 28116, 28924, 29719, 30500, 31269, 32025, 32769,
92 };
93
94 int ff_log2(uint32_t value)
95 {
96 uint8_t power_int;
97 uint8_t frac_x0;
98 uint16_t frac_dx;
99
100 // Stripping zeros from beginning
101 power_int = av_log2(value);
102 value <<= (31 - power_int);
103
104 // b31 is always non-zero now
105 frac_x0 = (value & 0x7c000000) >> 26; // b26-b31 and [32..63] -> [0..31]
106 frac_dx = (value & 0x03fff800) >> 11;
107
108 value = tab_log2[frac_x0];
109 value += (frac_dx * (tab_log2[frac_x0+1] - tab_log2[frac_x0])) >> 15;
110
111 return (power_int << 15) + value;
112 }
113
114 float ff_dot_productf(const float* a, const float* b, int length)
115 {
116 float sum = 0;
117 int i;
118
119 for(i=0; i<length; i++)
120 sum += a[i] * b[i];
121
122 return sum;
123 }