2 * Various fixed-point math operations
4 * Copyright (c) 2008 Vladimir Voroshilov
6 * This file is part of FFmpeg.
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.
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.
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
26 #include "libavutil/avassert.h"
29 #include "celp_math.h"
30 #include "libavutil/common.h"
34 * Cosine table: base_cos[i] = (1<<15) * cos(i*PI/64)
36 static const int16_t base_cos[64] =
38 32767, 32729, 32610, 32413, 32138, 31786, 31357, 30853,
39 30274, 29622, 28899, 28106, 27246, 26320, 25330, 24279,
40 23170, 22006, 20788, 19520, 18205, 16846, 15447, 14010,
41 12540, 11039, 9512, 7962, 6393, 4808, 3212, 1608,
42 0, -1608, -3212, -4808, -6393, -7962, -9512, -11039,
43 -12540, -14010, -15447, -16846, -18205, -19520, -20788, -22006,
44 -23170, -24279, -25330, -26320, -27246, -28106, -28899, -29622,
45 -30274, -30853, -31357, -31786, -32138, -32413, -32610, -32729
49 * Slope used to compute cos(x)
51 * cos(ind*64+offset) = base_cos[ind]+offset*slope_cos[ind]
52 * values multiplied by 1<<19
54 static const int16_t slope_cos[64] =
56 -632, -1893, -3150, -4399, -5638, -6863, -8072, -9261,
57 -10428, -11570, -12684, -13767, -14817, -15832, -16808, -17744,
58 -18637, -19486, -20287, -21039, -21741, -22390, -22986, -23526,
59 -24009, -24435, -24801, -25108, -25354, -25540, -25664, -25726,
60 -25726, -25664, -25540, -25354, -25108, -24801, -24435, -24009,
61 -23526, -22986, -22390, -21741, -21039, -20287, -19486, -18637,
62 -17744, -16808, -15832, -14817, -13767, -12684, -11570, -10428,
63 -9261, -8072, -6863, -5638, -4399, -3150, -1893, -632
67 * Table used to compute exp2(x)
69 * tab_exp2[i] = (1<<14) * exp2(i/32) = 2^(i/32) i=0..32
71 static const uint16_t tab_exp2[33] =
73 16384, 16743, 17109, 17484, 17867, 18258, 18658, 19066, 19484, 19911,
74 20347, 20792, 21247, 21713, 22188, 22674, 23170, 23678, 24196, 24726,
75 25268, 25821, 26386, 26964, 27554, 28158, 28774, 29405, 30048, 30706,
79 int16_t ff_cos(uint16_t arg)
82 uint8_t ind = arg >> 8;
84 av_assert2(arg < 0x4000);
86 return FFMAX(base_cos[ind] + ((slope_cos[ind] * offset) >> 12), -0x8000);
89 int ff_exp2(uint16_t power)
95 av_assert2(power <= 0x7fff);
97 frac_x0 = power >> 10;
98 frac_dx = (power & 0x03ff) << 5;
100 result = tab_exp2[frac_x0] << 15;
101 result += frac_dx * (tab_exp2[frac_x0+1] - tab_exp2[frac_x0]);
106 #else // G729_BITEXACT
109 * Cosine table: base_cos[i] = (1<<15) * cos(i*PI/64)
111 static const int16_t tab_cos[65] =
113 32767, 32738, 32617, 32421, 32145, 31793, 31364, 30860,
114 30280, 29629, 28905, 28113, 27252, 26326, 25336, 24285,
115 23176, 22011, 20793, 19525, 18210, 16851, 15451, 14014,
116 12543, 11043, 9515, 7965, 6395, 4810, 3214, 1609,
117 1, -1607, -3211, -4808, -6393, -7962, -9513, -11040,
118 -12541, -14012, -15449, -16848, -18207, -19523, -20791, -22009,
119 -23174, -24283, -25334, -26324, -27250, -28111, -28904, -29627,
120 -30279, -30858, -31363, -31792, -32144, -32419, -32616, -32736, -32768,
123 static const uint16_t exp2a[]=
125 0, 1435, 2901, 4400, 5931, 7496, 9096, 10730,
126 12400, 14106, 15850, 17632, 19454, 21315, 23216, 25160,
127 27146, 29175, 31249, 33368, 35534, 37747, 40009, 42320,
128 44682, 47095, 49562, 52082, 54657, 57289, 59979, 62727,
131 static const uint16_t exp2b[]=
133 3, 712, 1424, 2134, 2845, 3557, 4270, 4982,
134 5696, 6409, 7124, 7839, 8554, 9270, 9986, 10704,
135 11421, 12138, 12857, 13576, 14295, 15014, 15734, 16455,
136 17176, 17898, 18620, 19343, 20066, 20790, 21514, 22238,
139 int16_t ff_cos(uint16_t arg)
142 uint8_t ind = arg >> 8;
144 av_assert2(arg <= 0x3fff);
146 return tab_cos[ind] + (offset * (tab_cos[ind+1] - tab_cos[ind]) >> 8);
149 int ff_exp2(uint16_t power)
151 unsigned int result= exp2a[power>>10] + 0x10000;
153 av_assert2(power <= 0x7fff);
155 result= (result<<3) + ((result*exp2b[(power>>5)&31])>>17);
156 return result + ((result*(power&31)*89)>>22);
159 #endif // else G729_BITEXACT
162 * Table used to compute log2(x)
164 * tab_log2[i] = (1<<15) * log2(1 + i/32), i=0..32
166 static const uint16_t tab_log2[33] =
169 0, 1455, 2866, 4236, 5568, 6863, 8124, 9352,
170 10549, 11716, 12855, 13967, 15054, 16117, 17156, 18172,
171 19167, 20142, 21097, 22033, 22951, 23852, 24735, 25603,
172 26455, 27291, 28113, 28922, 29716, 30497, 31266, 32023, 32767,
174 4, 1459, 2870, 4240, 5572, 6867, 8127, 9355,
175 10552, 11719, 12858, 13971, 15057, 16120, 17158, 18175,
176 19170, 20145, 21100, 22036, 22954, 23854, 24738, 25605,
177 26457, 27294, 28116, 28924, 29719, 30500, 31269, 32025, 32769,
181 int ff_log2(uint32_t value)
187 // Stripping zeros from beginning
188 power_int = av_log2(value);
189 value <<= (31 - power_int);
191 // b31 is always non-zero now
192 frac_x0 = (value & 0x7c000000) >> 26; // b26-b31 and [32..63] -> [0..31]
193 frac_dx = (value & 0x03fff800) >> 11;
195 value = tab_log2[frac_x0];
196 value += (frac_dx * (tab_log2[frac_x0+1] - tab_log2[frac_x0])) >> 15;
198 return (power_int << 15) + value;
201 int64_t ff_dot_product(const int16_t *a, const int16_t *b, int length)
206 for (i = 0; i < length; i++)
207 sum += MUL16(a[i], b[i]);
212 float ff_dot_productf(const float* a, const float* b, int length)
217 for(i=0; i<length; i++)
223 void ff_celp_math_init(CELPMContext *c)
225 c->dot_productf = ff_dot_productf;
228 ff_celp_math_init_mips(c);