/[svn]/linuxsampler/trunk/src/voice.h
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Contents of /linuxsampler/trunk/src/voice.h

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Revision 38 - (show annotations) (download) (as text)
Tue Mar 16 13:25:39 2004 UTC (20 years, 1 month ago) by schoenebeck
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File size: 14457 byte(s)
* added filters (lowpass, bandpass and highpass), note that filter code is
  currently disabled by default, you have to explicitly enable it in
  src/voice.h by setting define ENABLE_FILTER to 1
* src/eg_vca.cpp: Decay_1 stage now using exponential curve

1 /***************************************************************************
2 * *
3 * LinuxSampler - modular, streaming capable sampler *
4 * *
5 * Copyright (C) 2003 by Benno Senoner and Christian Schoenebeck *
6 * *
7 * This program is free software; you can redistribute it and/or modify *
8 * it under the terms of the GNU General Public License as published by *
9 * the Free Software Foundation; either version 2 of the License, or *
10 * (at your option) any later version. *
11 * *
12 * This program is distributed in the hope that it will be useful, *
13 * but WITHOUT ANY WARRANTY; without even the implied warranty of *
14 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the *
15 * GNU General Public License for more details. *
16 * *
17 * You should have received a copy of the GNU General Public License *
18 * along with this program; if not, write to the Free Software *
19 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, *
20 * MA 02111-1307 USA *
21 ***************************************************************************/
22
23 #ifndef __VOICE_H__
24 #define __VOICE_H__
25
26 #include "global.h"
27 #include "diskthread.h"
28 #include "ringbuffer.h"
29 #include "stream.h"
30 #include "gig.h"
31 #include "eg_vca.h"
32 #include "rtelmemorypool.h"
33 #include "audiothread.h"
34 #include "filter.h"
35
36 #define MAX_PITCH 4 //FIXME: at the moment in octaves, should be changed into semitones
37 #define USE_LINEAR_INTERPOLATION 1 ///< set to 0 if you prefer cubic interpolation (slower, better quality)
38 #define ENABLE_FILTER 0 ///< if set to 0 then filter (VCF) code is ignored on compile time
39 #define FILTER_UPDATE_PERIOD 64 ///< amount of sample points after which filter parameters (cutoff, resonance) are going to be updated (higher value means less CPU load, but also worse parameter resolution)
40 #define FORCE_FILTER_USAGE 0 ///< if set to 1 then filter is always used, if set to 0 filter is used only in case the instrument file defined one
41
42 // Uncomment following line to override external cutoff controller
43 //#define OVERRIDE_FILTER_CUTOFF_CTRL 1 ///< set to an arbitrary MIDI control change controller (e.g. 1 for 'modulation wheel')
44
45 // Uncomment following line to override external resonance controller
46 //#define OVERRIDE_FILTER_RES_CTRL 91 ///< set to an arbitrary MIDI control change controller (e.g. 91 for 'effect 1 depth')
47
48 // Uncomment following line to override filter type
49 //#define OVERRIDE_FILTER_TYPE gig::vcf_type_lowpass ///< either gig::vcf_type_lowpass, gig::vcf_type_bandpass or gig::vcf_type_highpass
50
51
52 /// Reflects a MIDI controller
53 struct midi_ctrl {
54 uint8_t controller; ///< MIDI control change controller number
55 uint8_t value; ///< Current controller value
56 };
57
58 class Voice {
59 public:
60 // Attributes
61 int MIDIKey; ///< MIDI key number of the key that triggered the voice
62 uint ReleaseVelocity; ///< Reflects the release velocity value if a note-off command arrived for the voice.
63
64 // Static Attributes
65 static DiskThread* pDiskThread; ///< Pointer to the disk thread, to be able to order a disk stream and later to delete the stream again
66 static AudioThread* pEngine; ///< Pointer to the engine, to be able to access the event lists.
67
68 // Methods
69 Voice();
70 ~Voice();
71 void Kill();
72 void Render(uint Samples);
73 void Reset();
74 int Trigger(ModulationSystem::Event* pNoteOnEvent, int Pitch, gig::Instrument* pInstrument);
75 inline bool IsActive() { return Active; }
76 inline void SetOutputLeft(float* pOutput, uint MaxSamplesPerCycle) { this->pOutputLeft = pOutput; this->MaxSamplesPerCycle = MaxSamplesPerCycle; }
77 inline void SetOutputRight(float* pOutput, uint MaxSamplesPerCycle) { this->pOutputRight = pOutput; this->MaxSamplesPerCycle = MaxSamplesPerCycle; }
78 private:
79 // Types
80 enum playback_state_t {
81 playback_state_ram,
82 playback_state_disk,
83 playback_state_end
84 };
85
86 // Attributes
87 float Volume; ///< Volume level of the voice
88 float* pOutputLeft; ///< Audio output buffer (left channel)
89 float* pOutputRight; ///< Audio output buffer (right channel)
90 uint MaxSamplesPerCycle; ///< Size of each audio output buffer
91 double Pos; ///< Current playback position in sample
92 double Pitch; ///< Current pitch depth (number of sample points to move on with each render step)
93 gig::Sample* pSample; ///< Pointer to the sample to be played back
94 gig::Region* pRegion; ///< Pointer to the articulation information of the respective keyboard region of this voice
95 bool Active; ///< If this voice object is currently in usage
96 playback_state_t PlaybackState; ///< When a sample will be triggered, it will be first played from RAM cache and after a couple of sample points it will switch to disk streaming and at the end of a disk stream we have to add null samples, so the interpolator can do it's work correctly
97 bool DiskVoice; ///< If the sample is very short it completely fits into the RAM cache and doesn't need to be streamed from disk, in that case this flag is set to false
98 Stream::reference_t DiskStreamRef; ///< Reference / link to the disk stream
99 unsigned long MaxRAMPos; ///< The upper allowed limit (not actually the end) in the RAM sample cache, after that point it's not safe to chase the interpolator another time over over the current cache position, instead we switch to disk then.
100 bool RAMLoop; ///< If this voice has a loop defined which completely fits into the cached RAM part of the sample, in this case we handle the looping within the voice class, else if the loop is located in the disk stream part, we let the disk stream handle the looping
101 int LoopCyclesLeft; ///< In case there is a RAMLoop and it's not an endless loop; reflects number of loop cycles left to be passed
102 uint Delay; ///< Number of sample points the rendering process of this voice should be delayed (jitter correction), will be set to 0 after the first audio fragment cycle
103 EG_VCA EG1;
104 GigFilter FilterLeft;
105 GigFilter FilterRight;
106 midi_ctrl VCFCutoffCtrl;
107 midi_ctrl VCFResonanceCtrl;
108 ModulationSystem::Event* pTriggerEvent; ///< First event on the key's list the voice should process (only needed for the first audio fragment in which voice was triggered, after that it will be set to NULL).
109
110 // Methods
111 void ProcessEvents(uint Samples);
112 void Interpolate(uint Samples, sample_t* pSrc, uint Skip);
113 void InterpolateAndLoop(uint Samples, sample_t* pSrc, uint Skip);
114 inline void InterpolateOneStep_Stereo(sample_t* pSrc, int& i, float& effective_volume, float& pitch, float& cutoff, float& resonance) {
115 int pos_int = double_to_int(this->Pos); // integer position
116 float pos_fract = this->Pos - pos_int; // fractional part of position
117 pos_int <<= 1;
118
119 #if ENABLE_FILTER
120 UpdateFilter_Stereo(cutoff, resonance);
121 #endif // ENABLE_FILTER
122
123 #if USE_LINEAR_INTERPOLATION
124 #if ENABLE_FILTER
125 // left channel
126 this->pOutputLeft[i] += this->FilterLeft.Apply(effective_volume * (pSrc[pos_int] + pos_fract * (pSrc[pos_int+2] - pSrc[pos_int])));
127 // right channel
128 this->pOutputRight[i++] += this->FilterRight.Apply(effective_volume * (pSrc[pos_int+1] + pos_fract * (pSrc[pos_int+3] - pSrc[pos_int+1])));
129 #else // no filter
130 // left channel
131 this->pOutputLeft[i] += effective_volume * (pSrc[pos_int] + pos_fract * (pSrc[pos_int+2] - pSrc[pos_int]));
132 // right channel
133 this->pOutputRight[i++] += effective_volume * (pSrc[pos_int+1] + pos_fract * (pSrc[pos_int+3] - pSrc[pos_int+1]));
134 #endif // ENABLE_FILTER
135 #else // polynomial interpolation
136 // calculate left channel
137 float xm1 = pSrc[pos_int];
138 float x0 = pSrc[pos_int+2];
139 float x1 = pSrc[pos_int+4];
140 float x2 = pSrc[pos_int+6];
141 float a = (3 * (x0 - x1) - xm1 + x2) / 2;
142 float b = 2 * x1 + xm1 - (5 * x0 + x2) / 2;
143 float c = (x1 - xm1) / 2;
144 #if ENABLE_FILTER
145 this->pOutputLeft[i] += this->FilterLeft.Apply(effective_volume * ((((a * pos_fract) + b) * pos_fract + c) * pos_fract + x0));
146 #else // no filter
147 this->pOutputLeft[i] += effective_volume * ((((a * pos_fract) + b) * pos_fract + c) * pos_fract + x0);
148 #endif // ENABLE_FILTER
149
150 //calculate right channel
151 xm1 = pSrc[pos_int+1];
152 x0 = pSrc[pos_int+3];
153 x1 = pSrc[pos_int+5];
154 x2 = pSrc[pos_int+7];
155 a = (3 * (x0 - x1) - xm1 + x2) / 2;
156 b = 2 * x1 + xm1 - (5 * x0 + x2) / 2;
157 c = (x1 - xm1) / 2;
158 #if ENABLE_FILTER
159 this->pOutputRight[i++] += this->FilterRight.Apply(effective_volume * ((((a * pos_fract) + b) * pos_fract + c) * pos_fract + x0));
160 #else // no filter
161 this->pOutputRight[i++] += effective_volume * ((((a * pos_fract) + b) * pos_fract + c) * pos_fract + x0);
162 #endif // ENABLE_FILTER
163 #endif // USE_LINEAR_INTERPOLATION
164
165 this->Pos += pitch;
166 }
167 inline void InterpolateOneStep_Mono(sample_t* pSrc, int& i, float& effective_volume, float& pitch, float& cutoff, float& resonance) {
168 int pos_int = double_to_int(this->Pos); // integer position
169 float pos_fract = this->Pos - pos_int; // fractional part of position
170
171 #if ENABLE_FILTER
172 UpdateFilter_Mono(cutoff, resonance);
173 #endif // ENABLE_FILTER
174
175 #if USE_LINEAR_INTERPOLATION
176 float sample_point = effective_volume * (pSrc[pos_int] + pos_fract * (pSrc[pos_int+1] - pSrc[pos_int]));
177 #else // polynomial interpolation
178 float xm1 = pSrc[pos_int];
179 float x0 = pSrc[pos_int+1];
180 float x1 = pSrc[pos_int+2];
181 float x2 = pSrc[pos_int+3];
182 float a = (3 * (x0 - x1) - xm1 + x2) / 2;
183 float b = 2 * x1 + xm1 - (5 * x0 + x2) / 2;
184 float c = (x1 - xm1) / 2;
185 float sample_point = effective_volume * ((((a * pos_fract) + b) * pos_fract + c) * pos_fract + x0);
186 #endif // USE_LINEAR_INTERPOLATION
187
188 #if ENABLE_FILTER
189 sample_point = this->FilterLeft.Apply(sample_point);
190 #endif // ENABLE_FILTER
191
192 this->pOutputLeft[i] += sample_point;
193 this->pOutputRight[i++] += sample_point;
194
195 this->Pos += pitch;
196 }
197 inline void UpdateFilter_Stereo(float& cutoff, float& resonance) {
198 static int updatecounter = 0; // we update the filter all FILTER_UPDATE_PERIOD samples
199 if (!(++updatecounter % FILTER_UPDATE_PERIOD) && cutoff != FilterLeft.Cutoff() || resonance != FilterLeft.Resonance()) {
200 FilterLeft.SetParameters(cutoff, resonance, ModulationSystem::SampleRate());
201 FilterRight.SetParameters(cutoff, resonance, ModulationSystem::SampleRate());
202 }
203 }
204 inline void UpdateFilter_Mono(float& cutoff, float& resonance) {
205 static int updatecounter = 0; // we update the filter all FILTER_UPDATE_PERIOD samples
206 if (!(++updatecounter % FILTER_UPDATE_PERIOD) && cutoff != FilterLeft.Cutoff() || resonance != FilterLeft.Resonance()) {
207 FilterLeft.SetParameters(cutoff, resonance, ModulationSystem::SampleRate());
208 }
209 }
210 inline void ForceUpdateFilter_Stereo(float& cutoff, float& resonance) {
211 if (cutoff != FilterLeft.Cutoff() || resonance != FilterLeft.Resonance()) {
212 FilterLeft.SetParameters(cutoff, resonance, ModulationSystem::SampleRate());
213 FilterRight.SetParameters(cutoff, resonance, ModulationSystem::SampleRate());
214 }
215 }
216 inline void ForceUpdateFilter_Mono(float& cutoff, float& resonance) {
217 if (cutoff != FilterLeft.Cutoff() || resonance != FilterLeft.Resonance()) {
218 FilterLeft.SetParameters(cutoff, resonance, ModulationSystem::SampleRate());
219 }
220 }
221 inline float Constrain(float ValueToCheck, float Min, float Max) {
222 if (ValueToCheck > Max) ValueToCheck = Max;
223 else if (ValueToCheck < Min) ValueToCheck = Min;
224 return ValueToCheck;
225 }
226 inline int double_to_int(double f) {
227 #if ARCH_X86
228 int i;
229 __asm__ ("fistl %0" : "=m"(i) : "st"(f - 0.5) );
230 return i;
231 #else
232 return (int) f;
233 #endif // ARCH_X86
234 }
235 };
236
237 #endif // __VOICE_H__

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