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 #ifdef G729_BITEXACT
33 static const uint16_t exp2a[]=
34 {
35 0, 1435, 2901, 4400, 5931, 7496, 9096, 10730,
36 12400, 14106, 15850, 17632, 19454, 21315, 23216, 25160,
37 27146, 29175, 31249, 33368, 35534, 37747, 40009, 42320,
38 44682, 47095, 49562, 52082, 54657, 57289, 59979, 62727,
39 };
40
41 static const uint16_t exp2b[]=
42 {
43 3, 712, 1424, 2134, 2845, 3557, 4270, 4982,
44 5696, 6409, 7124, 7839, 8554, 9270, 9986, 10704,
45 11421, 12138, 12857, 13576, 14295, 15014, 15734, 16455,
46 17176, 17898, 18620, 19343, 20066, 20790, 21514, 22238,
47 };
48
ff_exp2(uint16_t power)49 int ff_exp2(uint16_t power)
50 {
51 unsigned int result= exp2a[power>>10] + 0x10000;
52
53 av_assert2(power <= 0x7fff);
54
55 result= (result<<3) + ((result*exp2b[(power>>5)&31])>>17);
56 return result + ((result*(power&31)*89)>>22);
57 }
58 #endif
59
60 /**
61 * Table used to compute log2(x)
62 *
63 * tab_log2[i] = (1<<15) * log2(1 + i/32), i=0..32
64 */
65 static const uint16_t tab_log2[33] =
66 {
67 #ifdef G729_BITEXACT
68 0, 1455, 2866, 4236, 5568, 6863, 8124, 9352,
69 10549, 11716, 12855, 13967, 15054, 16117, 17156, 18172,
70 19167, 20142, 21097, 22033, 22951, 23852, 24735, 25603,
71 26455, 27291, 28113, 28922, 29716, 30497, 31266, 32023, 32767,
72 #else
73 4, 1459, 2870, 4240, 5572, 6867, 8127, 9355,
74 10552, 11719, 12858, 13971, 15057, 16120, 17158, 18175,
75 19170, 20145, 21100, 22036, 22954, 23854, 24738, 25605,
76 26457, 27294, 28116, 28924, 29719, 30500, 31269, 32025, 32769,
77 #endif
78 };
79
ff_log2_q15(uint32_t value)80 int ff_log2_q15(uint32_t value)
81 {
82 uint8_t power_int;
83 uint8_t frac_x0;
84 uint16_t frac_dx;
85
86 // Stripping zeros from beginning
87 power_int = av_log2(value);
88 value <<= (31 - power_int);
89
90 // b31 is always non-zero now
91 frac_x0 = (value & 0x7c000000) >> 26; // b26-b31 and [32..63] -> [0..31]
92 frac_dx = (value & 0x03fff800) >> 11;
93
94 value = tab_log2[frac_x0];
95 value += (frac_dx * (tab_log2[frac_x0+1] - tab_log2[frac_x0])) >> 15;
96
97 return (power_int << 15) + value;
98 }
99
ff_dot_product(const int16_t * a,const int16_t * b,int length)100 int64_t ff_dot_product(const int16_t *a, const int16_t *b, int length)
101 {
102 int i;
103 int64_t sum = 0;
104
105 for (i = 0; i < length; i++)
106 sum += MUL16(a[i], b[i]);
107
108 return sum;
109 }
110
ff_dot_productf(const float * a,const float * b,int length)111 float ff_dot_productf(const float* a, const float* b, int length)
112 {
113 float sum = 0;
114 int i;
115
116 for(i=0; i<length; i++)
117 sum += a[i] * b[i];
118
119 return sum;
120 }
121
ff_celp_math_init(CELPMContext * c)122 void ff_celp_math_init(CELPMContext *c)
123 {
124 c->dot_productf = ff_dot_productf;
125
126 if(HAVE_MIPSFPU)
127 ff_celp_math_init_mips(c);
128 }
129