libsidplayfp  1.8.7
mixer.h
1 /*
2  * This file is part of libsidplayfp, a SID player engine.
3  *
4  * Copyright 2011-2015 Leandro Nini <drfiemost@users.sourceforge.net>
5  * Copyright 2007-2010 Antti Lankila
6  * Copyright (C) 2000 Simon White
7  *
8  * This program is free software; you can redistribute it and/or modify
9  * it under the terms of the GNU General Public License as published by
10  * the Free Software Foundation; either version 2 of the License, or
11  * (at your option) any later version.
12  *
13  * This program 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
16  * GNU General Public License for more details.
17  *
18  * You should have received a copy of the GNU General Public License
19  * along with this program; if not, write to the Free Software
20  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
21  */
22 
23 
24 #ifndef MIXER_H
25 #define MIXER_H
26 
27 #include <stdint.h>
28 #include <cstdlib>
29 
30 #include <vector>
31 
32 class sidemu;
33 
37 class Mixer
38 {
39 public:
41  static const unsigned int MAX_SIDS = 3;
42 
43  static const int_least32_t SCALE_FACTOR = 1 << 16;
44  static const int_least32_t C1 = static_cast<int_least32_t>(1.0 / (1.0 + 0.7071067812) * SCALE_FACTOR);
45  static const int_least32_t C2 = static_cast<int_least32_t>(0.7071067812 / (1.0 + 0.7071067812) * SCALE_FACTOR);
46 
47 private:
48  typedef int_least32_t (Mixer::*mixer_func_t)() const;
49 
50 public:
52  static const int_least32_t VOLUME_MAX = 1024;
53 
54 private:
55  std::vector<sidemu*> m_chips;
56  std::vector<short*> m_buffers;
57 
58  std::vector<int_least32_t> m_iSamples;
59  std::vector<int_least32_t> m_volume;
60 
61  std::vector<mixer_func_t> m_mix;
62 
63  int oldRandomValue;
64  int m_fastForwardFactor;
65 
66  // Mixer settings
67  short *m_sampleBuffer;
68  uint_least32_t m_sampleCount;
69  uint_least32_t m_sampleIndex;
70 
71  bool m_stereo;
72 
73 private:
74  void updateParams();
75 
76  int triangularDithering()
77  {
78  const int prevValue = oldRandomValue;
79  oldRandomValue = rand() & (VOLUME_MAX-1);
80  return oldRandomValue - prevValue;
81  }
82 
83  /*
84  * Channel matrix
85  *
86  * C1
87  * L 1.0
88  * R 1.0
89  *
90  * C1 C2
91  * L 1.0 0.0
92  * R 0.0 1.0
93  *
94  * C1 C2 C3
95  * L 1/1.707 0.707/1.707 0.0
96  * R 0.0 0.707/1.707 1/1.707
97  */
98 
99  // Mono mixing
100  int_least32_t mono_OneChip() const { return m_iSamples[0]; }
101  int_least32_t mono_TwoChips() const { return (m_iSamples[0] + m_iSamples[1]) / 2; }
102  int_least32_t mono_ThreeChips() const { return (m_iSamples[0] + m_iSamples[1] + m_iSamples[2]) / 3; }
103 
104  // Stereo mixing
105  int_least32_t stereo_OneChip() const { return m_iSamples[0]; }
106 
107  int_least32_t stereo_ch1_TwoChips() const { return m_iSamples[0]; }
108  int_least32_t stereo_ch2_TwoChips() const { return m_iSamples[1]; }
109 
110  int_least32_t stereo_ch1_ThreeChips() const { return (C1*m_iSamples[0] + C2*m_iSamples[1]) / SCALE_FACTOR; }
111  int_least32_t stereo_ch2_ThreeChips() const { return (C2*m_iSamples[1] + C1*m_iSamples[2]) / SCALE_FACTOR; }
112 
113 
114 public:
118  Mixer() :
119  oldRandomValue(0),
120  m_fastForwardFactor(1),
121  m_sampleCount(0),
122  m_stereo(false)
123  {
124  m_mix.push_back(&Mixer::mono_OneChip);
125  }
126 
130  void doMix();
131 
135  void clockChips();
136 
140  void resetBufs();
141 
148  void begin(short *buffer, uint_least32_t count);
149 
153  void clearSids();
154 
160  void addSid(sidemu *chip);
161 
168  sidemu* getSid(unsigned int i) const { return (i < m_chips.size()) ? m_chips[i] : 0; }
169 
176  bool setFastForward(int ff);
177 
184  void setVolume(int_least32_t left, int_least32_t right);
185 
191  void setStereo(bool stereo);
192 
196  bool notFinished() const { return m_sampleIndex != m_sampleCount; }
197 
201  uint_least32_t samplesGenerated() const { return m_sampleIndex; }
202 };
203 
204 #endif // MIXER_H
static const unsigned int MAX_SIDS
Maximum number of supported SIDs.
Definition: mixer.h:41
void clockChips()
Definition: mixer.cpp:59
static const int_least32_t VOLUME_MAX
Maximum allowed volume, must be a power of 2.
Definition: mixer.h:52
Definition: mixer.h:37
void setStereo(bool stereo)
Definition: mixer.cpp:170
Definition: sidemu.h:39
uint_least32_t samplesGenerated() const
Definition: mixer.h:201
bool setFastForward(int ff)
Definition: mixer.cpp:182
void setVolume(int_least32_t left, int_least32_t right)
Definition: mixer.cpp:191
void doMix()
Definition: mixer.cpp:69
Mixer()
Definition: mixer.h:118
void addSid(sidemu *chip)
Definition: mixer.cpp:156
void clearSids()
Definition: mixer.cpp:150
sidemu * getSid(unsigned int i) const
Definition: mixer.h:168
bool notFinished() const
Definition: mixer.h:196
void begin(short *buffer, uint_least32_t count)
Definition: mixer.cpp:125
void resetBufs()
Definition: mixer.cpp:64