1 /*
2 * Copyright (c) 2011 The WebRTC project authors. All Rights Reserved.
3 *
4 * Use of this source code is governed by a BSD-style license
5 * that can be found in the LICENSE file in the root of the source
6 * tree. An additional intellectual property rights grant can be found
7 * in the file PATENTS. All contributing project authors may
8 * be found in the AUTHORS file in the root of the source tree.
9 */
10
11
12 /*
13 * This file contains implementations of the randomization functions
14 * WebRtcSpl_RandU()
15 * WebRtcSpl_RandN()
16 * WebRtcSpl_RandUArray()
17 *
18 * The description header can be found in signal_processing_library.h
19 *
20 */
21
22 #include "webrtc/common_audio/signal_processing/include/signal_processing_library.h"
23
24 static const uint32_t kMaxSeedUsed = 0x80000000;
25
26 static const int16_t kRandNTable[] = {
27 9178, -7260, 40, 10189, 4894, -3531, -13779, 14764,
28 -4008, -8884, -8990, 1008, 7368, 5184, 3251, -5817,
29 -9786, 5963, 1770, 8066, -7135, 10772, -2298, 1361,
30 6484, 2241, -8633, 792, 199, -3344, 6553, -10079,
31 -15040, 95, 11608, -12469, 14161, -4176, 2476, 6403,
32 13685, -16005, 6646, 2239, 10916, -3004, -602, -3141,
33 2142, 14144, -5829, 5305, 8209, 4713, 2697, -5112,
34 16092, -1210, -2891, -6631, -5360, -11878, -6781, -2739,
35 -6392, 536, 10923, 10872, 5059, -4748, -7770, 5477,
36 38, -1025, -2892, 1638, 6304, 14375, -11028, 1553,
37 -1565, 10762, -393, 4040, 5257, 12310, 6554, -4799,
38 4899, -6354, 1603, -1048, -2220, 8247, -186, -8944,
39 -12004, 2332, 4801, -4933, 6371, 131, 8614, -5927,
40 -8287, -22760, 4033, -15162, 3385, 3246, 3153, -5250,
41 3766, 784, 6494, -62, 3531, -1582, 15572, 662,
42 -3952, -330, -3196, 669, 7236, -2678, -6569, 23319,
43 -8645, -741, 14830, -15976, 4903, 315, -11342, 10311,
44 1858, -7777, 2145, 5436, 5677, -113, -10033, 826,
45 -1353, 17210, 7768, 986, -1471, 8291, -4982, 8207,
46 -14911, -6255, -2449, -11881, -7059, -11703, -4338, 8025,
47 7538, -2823, -12490, 9470, -1613, -2529, -10092, -7807,
48 9480, 6970, -12844, 5123, 3532, 4816, 4803, -8455,
49 -5045, 14032, -4378, -1643, 5756, -11041, -2732, -16618,
50 -6430, -18375, -3320, 6098, 5131, -4269, -8840, 2482,
51 -7048, 1547, -21890, -6505, -7414, -424, -11722, 7955,
52 1653, -17299, 1823, 473, -9232, 3337, 1111, 873,
53 4018, -8982, 9889, 3531, -11763, -3799, 7373, -4539,
54 3231, 7054, -8537, 7616, 6244, 16635, 447, -2915,
55 13967, 705, -2669, -1520, -1771, -16188, 5956, 5117,
56 6371, -9936, -1448, 2480, 5128, 7550, -8130, 5236,
57 8213, -6443, 7707, -1950, -13811, 7218, 7031, -3883,
58 67, 5731, -2874, 13480, -3743, 9298, -3280, 3552,
59 -4425, -18, -3785, -9988, -5357, 5477, -11794, 2117,
60 1416, -9935, 3376, 802, -5079, -8243, 12652, 66,
61 3653, -2368, 6781, -21895, -7227, 2487, 7839, -385,
62 6646, -7016, -4658, 5531, -1705, 834, 129, 3694,
63 -1343, 2238, -22640, -6417, -11139, 11301, -2945, -3494,
64 -5626, 185, -3615, -2041, -7972, -3106, -60, -23497,
65 -1566, 17064, 3519, 2518, 304, -6805, -10269, 2105,
66 1936, -426, -736, -8122, -1467, 4238, -6939, -13309,
67 360, 7402, -7970, 12576, 3287, 12194, -6289, -16006,
68 9171, 4042, -9193, 9123, -2512, 6388, -4734, -8739,
69 1028, -5406, -1696, 5889, -666, -4736, 4971, 3565,
70 9362, -6292, 3876, -3652, -19666, 7523, -4061, 391,
71 -11773, 7502, -3763, 4929, -9478, 13278, 2805, 4496,
72 7814, 16419, 12455, -14773, 2127, -2746, 3763, 4847,
73 3698, 6978, 4751, -6957, -3581, -45, 6252, 1513,
74 -4797, -7925, 11270, 16188, -2359, -5269, 9376, -10777,
75 7262, 20031, -6515, -2208, -5353, 8085, -1341, -1303,
76 7333, 5576, 3625, 5763, -7931, 9833, -3371, -10305,
77 6534, -13539, -9971, 997, 8464, -4064, -1495, 1857,
78 13624, 5458, 9490, -11086, -4524, 12022, -550, -198,
79 408, -8455, -7068, 10289, 9712, -3366, 9028, -7621,
80 -5243, 2362, 6909, 4672, -4933, -1799, 4709, -4563,
81 -62, -566, 1624, -7010, 14730, -17791, -3697, -2344,
82 -1741, 7099, -9509, -6855, -1989, 3495, -2289, 2031,
83 12784, 891, 14189, -3963, -5683, 421, -12575, 1724,
84 -12682, -5970, -8169, 3143, -1824, -5488, -5130, 8536,
85 12799, 794, 5738, 3459, -11689, -258, -3738, -3775,
86 -8742, 2333, 8312, -9383, 10331, 13119, 8398, 10644,
87 -19433, -6446, -16277, -11793, 16284, 9345, 15222, 15834,
88 2009, -7349, 130, -14547, 338, -5998, 3337, 21492,
89 2406, 7703, -951, 11196, -564, 3406, 2217, 4806,
90 2374, -5797, 11839, 8940, -11874, 18213, 2855, 10492
91 };
92
IncreaseSeed(uint32_t * seed)93 static uint32_t IncreaseSeed(uint32_t* seed) {
94 seed[0] = (seed[0] * ((int32_t)69069) + 1) & (kMaxSeedUsed - 1);
95 return seed[0];
96 }
97
WebRtcSpl_RandU(uint32_t * seed)98 int16_t WebRtcSpl_RandU(uint32_t* seed) {
99 return (int16_t)(IncreaseSeed(seed) >> 16);
100 }
101
WebRtcSpl_RandN(uint32_t * seed)102 int16_t WebRtcSpl_RandN(uint32_t* seed) {
103 return kRandNTable[IncreaseSeed(seed) >> 23];
104 }
105
106 // Creates an array of uniformly distributed variables.
WebRtcSpl_RandUArray(int16_t * vector,int16_t vector_length,uint32_t * seed)107 int16_t WebRtcSpl_RandUArray(int16_t* vector,
108 int16_t vector_length,
109 uint32_t* seed) {
110 int i;
111 for (i = 0; i < vector_length; i++) {
112 vector[i] = WebRtcSpl_RandU(seed);
113 }
114 return vector_length;
115 }
116