modules/audio_coding/neteq4/random_vector.cc

/*
 *  Copyright (c) 2011 The WebRTC project authors. All Rights Reserved.
 *
 *  Use of this source code is governed by a BSD-style license
 *  that can be found in the LICENSE file in the root of the source
 *  tree. An additional intellectual property rights grant can be found
 *  in the file PATENTS.  All contributing project authors may
 *  be found in the AUTHORS file in the root of the source tree.
 */

#include "webrtc/modules/audio_coding/neteq4/random_vector.h"

namespace webrtc {

const int16_t RandomVector::kRandomTable[RandomVector::kRandomTableSize] = {
    2680, 5532, 441, 5520, 16170, -5146, -1024, -8733, 3115, 9598, -10380,
    -4959, -1280, -21716, 7133, -1522, 13458, -3902, 2789, -675, 3441, 5016,
    -13599, -4003, -2739, 3922, -7209, 13352, -11617, -7241, 12905, -2314, 5426,
    10121, -9702, 11207, -13542, 1373, 816, -5934, -12504, 4798, 1811, 4112,
    -613, 201, -10367, -2960, -2419, 3442, 4299, -6116, -6092, 1552, -1650,
    -480, -1237, 18720, -11858, -8303, -8212, 865, -2890, -16968, 12052, -5845,
    -5912, 9777, -5665, -6294, 5426, -4737, -6335, 1652, 761, 3832, 641, -8552,
    -9084, -5753, 8146, 12156, -4915, 15086, -1231, -1869, 11749, -9319, -6403,
    11407, 6232, -1683, 24340, -11166, 4017, -10448, 3153, -2936, 6212, 2891,
    -866, -404, -4807, -2324, -1917, -2388, -6470, -3895, -10300, 5323, -5403,
    2205, 4640, 7022, -21186, -6244, -882, -10031, -3395, -12885, 7155, -5339,
    5079, -2645, -9515, 6622, 14651, 15852, 359, 122, 8246, -3502, -6696, -3679,
    -13535, -1409, -704, -7403, -4007, 1798, 279, -420, -12796, -14219, 1141,
    3359, 11434, 7049, -6684, -7473, 14283, -4115, -9123, -8969, 4152, 4117,
    13792, 5742, 16168, 8661, -1609, -6095, 1881, 14380, -5588, 6758, -6425,
    -22969, -7269, 7031, 1119, -1611, -5850, -11281, 3559, -8952, -10146, -4667,
    -16251, -1538, 2062, -1012, -13073, 227, -3142, -5265, 20, 5770, -7559,
    4740, -4819, 992, -8208, -7130, -4652, 6725, 7369, -1036, 13144, -1588,
    -5304, -2344, -449, -5705, -8894, 5205, -17904, -11188, -1022, 4852, 10101,
    -5255, -4200, -752, 7941, -1543, 5959, 14719, 13346, 17045, -15605, -1678,
    -1600, -9230, 68, 23348, 1172, 7750, 11212, -18227, 9956, 4161, 883, 3947,
    4341, 1014, -4889, -2603, 1246, -5630, -3596, -870, -1298, 2784, -3317,
    -6612, -20541, 4166, 4181, -8625, 3562, 12890, 4761, 3205, -12259, -8579 };

void RandomVector::Reset() {
  seed_ = 777;
  seed_increment_ = 1;
}

void RandomVector::Generate(size_t length, int16_t* output) {
  for (size_t i = 0; i < length; i++) {
    seed_ += seed_increment_;
    size_t position = seed_ & (kRandomTableSize - 1);
    output[i] = kRandomTable[position];
  }
}

void RandomVector::IncreaseSeedIncrement(int16_t increase_by) {
  seed_increment_+= increase_by;
  seed_increment_ &= kRandomTableSize - 1;
}
}