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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 <inttypes.h> | |
24 | #include <limits.h> | |
25 | ||
26 | #include "libavutil/avassert.h" | |
27 | #include "avcodec.h" | |
28 | #include "mathops.h" | |
29 | #include "celp_math.h" | |
30 | #include "libavutil/common.h" | |
31 | ||
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 | ||
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 | ||
58 | /** | |
59 | * Table used to compute log2(x) | |
60 | * | |
61 | * tab_log2[i] = (1<<15) * log2(1 + i/32), i=0..32 | |
62 | */ | |
63 | static const uint16_t tab_log2[33] = | |
64 | { | |
65 | #ifdef G729_BITEXACT | |
66 | 0, 1455, 2866, 4236, 5568, 6863, 8124, 9352, | |
67 | 10549, 11716, 12855, 13967, 15054, 16117, 17156, 18172, | |
68 | 19167, 20142, 21097, 22033, 22951, 23852, 24735, 25603, | |
69 | 26455, 27291, 28113, 28922, 29716, 30497, 31266, 32023, 32767, | |
70 | #else | |
71 | 4, 1459, 2870, 4240, 5572, 6867, 8127, 9355, | |
72 | 10552, 11719, 12858, 13971, 15057, 16120, 17158, 18175, | |
73 | 19170, 20145, 21100, 22036, 22954, 23854, 24738, 25605, | |
74 | 26457, 27294, 28116, 28924, 29719, 30500, 31269, 32025, 32769, | |
75 | #endif | |
76 | }; | |
77 | ||
78 | int ff_log2_q15(uint32_t value) | |
79 | { | |
80 | uint8_t power_int; | |
81 | uint8_t frac_x0; | |
82 | uint16_t frac_dx; | |
83 | ||
84 | // Stripping zeros from beginning | |
85 | power_int = av_log2(value); | |
86 | value <<= (31 - power_int); | |
87 | ||
88 | // b31 is always non-zero now | |
89 | frac_x0 = (value & 0x7c000000) >> 26; // b26-b31 and [32..63] -> [0..31] | |
90 | frac_dx = (value & 0x03fff800) >> 11; | |
91 | ||
92 | value = tab_log2[frac_x0]; | |
93 | value += (frac_dx * (tab_log2[frac_x0+1] - tab_log2[frac_x0])) >> 15; | |
94 | ||
95 | return (power_int << 15) + value; | |
96 | } | |
97 | ||
98 | int64_t ff_dot_product(const int16_t *a, const int16_t *b, int length) | |
99 | { | |
100 | int i; | |
101 | int64_t sum = 0; | |
102 | ||
103 | for (i = 0; i < length; i++) | |
104 | sum += MUL16(a[i], b[i]); | |
105 | ||
106 | return sum; | |
107 | } | |
108 | ||
109 | float ff_dot_productf(const float* a, const float* b, int length) | |
110 | { | |
111 | float sum = 0; | |
112 | int i; | |
113 | ||
114 | for(i=0; i<length; i++) | |
115 | sum += a[i] * b[i]; | |
116 | ||
117 | return sum; | |
118 | } | |
119 | ||
120 | void ff_celp_math_init(CELPMContext *c) | |
121 | { | |
122 | c->dot_productf = ff_dot_productf; | |
123 | ||
124 | if(HAVE_MIPSFPU) | |
125 | ff_celp_math_init_mips(c); | |
126 | } |