1 /*
2  *  Copyright (c) 2012 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 #ifndef WEBRTC_MODULES_AUDIO_CODING_NETEQ_RANDOM_VECTOR_H_
12 #define WEBRTC_MODULES_AUDIO_CODING_NETEQ_RANDOM_VECTOR_H_
13 
14 #include <string.h>  // size_t
15 
16 #include "webrtc/base/constructormagic.h"
17 #include "webrtc/typedefs.h"
18 
19 namespace webrtc {
20 
21 // This class generates pseudo-random samples.
22 class RandomVector {
23  public:
24   static const size_t kRandomTableSize = 256;
25   static const int16_t kRandomTable[kRandomTableSize];
26 
RandomVector()27   RandomVector()
28       : seed_(777),
29         seed_increment_(1) {
30   }
31 
32   void Reset();
33 
34   void Generate(size_t length, int16_t* output);
35 
36   void IncreaseSeedIncrement(int16_t increase_by);
37 
38   // Accessors and mutators.
seed_increment()39   int16_t seed_increment() { return seed_increment_; }
set_seed_increment(int16_t value)40   void set_seed_increment(int16_t value) { seed_increment_ = value; }
41 
42  private:
43   uint32_t seed_;
44   int16_t seed_increment_;
45 
46   RTC_DISALLOW_COPY_AND_ASSIGN(RandomVector);
47 };
48 
49 }  // namespace webrtc
50 #endif  // WEBRTC_MODULES_AUDIO_CODING_NETEQ_RANDOM_VECTOR_H_
51