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

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Revision 31 - (show annotations) (download) (as text)
Sun Jan 18 20:31:31 2004 UTC (20 years, 3 months ago) by schoenebeck
File MIME type: text/x-c++hdr
File size: 9038 byte(s)
* Added JACK support: Audio rendering process is now callback based and
  independant of used audio output system. Interfaces to other audio output
  systems can be added by creating a class derived from abstract base class
  'AudioIO' and embedding the new class into linuxsampler.cpp.
* src/audiothread.cpp: applied patch from Vladimir Senkov which fixes
  hanging notes in conjunction with the sustain pedal

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
33 #define MAX_PITCH 4 //FIXME: at the moment in octaves, should be changed into semitones
34 #define USE_LINEAR_INTERPOLATION 1 ///< set to 0 if you prefer cubic interpolation (slower, better quality)
35
36 class Voice {
37 public:
38 // Attributes
39 int MIDIKey; ///< MIDI key number of the key that triggered the voice
40 Voice** pSelfPtr; ///< FIXME: hack to be able to remove the voice from the active voices list within the audio thread, ugly but fast
41 uint ReleaseVelocity; ///< Reflects the release velocity value if a note-off command arrived for the voice.
42
43 // Methods
44 Voice(DiskThread* pDiskThread);
45 ~Voice();
46 void Kill();
47 void Release();
48 void Render(uint Samples);
49 int Trigger(int MIDIKey, uint8_t Velocity, gig::Instrument* Instrument);
50 inline bool IsActive() { return Active; }
51 inline void SetOutputLeft(float* pOutput, uint MaxSamplesPerCycle) { this->pOutputLeft = pOutput; this->MaxSamplesPerCycle = MaxSamplesPerCycle; }
52 inline void SetOutputRight(float* pOutput, uint MaxSamplesPerCycle) { this->pOutputRight = pOutput; this->MaxSamplesPerCycle = MaxSamplesPerCycle; }
53 private:
54 // Types
55 enum playback_state_t {
56 playback_state_ram,
57 playback_state_disk,
58 playback_state_end
59 };
60
61 // Attributes
62 float Volume; ///< Volume level of the voice
63 float* pOutputLeft; ///< Audio output buffer (left channel)
64 float* pOutputRight; ///< Audio output buffer (right channel)
65 uint MaxSamplesPerCycle; ///< Size of each audio output buffer
66 double Pos; ///< Current playback position in sample
67 double CurrentPitch; ///< Current pitch depth (number of sample points to move on with each render step)
68 gig::Sample* pSample; ///< Pointer to the sample to be played back
69 gig::Region* pRegion; ///< Pointer to the articulation information of the respective keyboard region of this voice
70 bool Active; ///< If this voice object is currently in usage
71 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
72 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
73 Stream::reference_t DiskStreamRef; ///< Reference / link to the disk stream
74 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.
75 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
76 int LoopCyclesLeft; ///< In case there is a RAMLoop and it's not an endless loop; reflects number of loop cycles left to be passed
77 EG_VCA EG1;
78
79 // Static Attributes
80 static DiskThread* pDiskThread; ///< Pointer to the disk thread, to be able to order a disk stream and later to delete the stream again
81
82 // Methods
83 void Interpolate(uint Samples, sample_t* pSrc);
84 void InterpolateAndLoop(uint Samples, sample_t* pSrc);
85 inline void InterpolateOneStep_Stereo(sample_t* pSrc, int& i, float& effective_volume) {
86 int pos_int = double_to_int(this->Pos); // integer position
87 float pos_fract = this->Pos - pos_int; // fractional part of position
88 pos_int <<= 1;
89
90 #if USE_LINEAR_INTERPOLATION
91 // left channel
92 this->pOutputLeft[i] += effective_volume * (pSrc[pos_int] + pos_fract * (pSrc[pos_int+2] - pSrc[pos_int]));
93 // right channel
94 this->pOutputRight[i++] += effective_volume * (pSrc[pos_int+1] + pos_fract * (pSrc[pos_int+3] - pSrc[pos_int+1]));
95 #else // polynomial interpolation
96 // calculate left channel
97 float xm1 = pSrc[pos_int];
98 float x0 = pSrc[pos_int+2];
99 float x1 = pSrc[pos_int+4];
100 float x2 = pSrc[pos_int+6];
101 float a = (3 * (x0 - x1) - xm1 + x2) / 2;
102 float b = 2 * x1 + xm1 - (5 * x0 + x2) / 2;
103 float c = (x1 - xm1) / 2;
104 this->pOutputLeft[i] += effective_volume * ((((a * pos_fract) + b) * pos_fract + c) * pos_fract + x0);
105
106 //calculate right channel
107 xm1 = pSrc[pos_int+1];
108 x0 = pSrc[pos_int+3];
109 x1 = pSrc[pos_int+5];
110 x2 = pSrc[pos_int+7];
111 a = (3 * (x0 - x1) - xm1 + x2) / 2;
112 b = 2 * x1 + xm1 - (5 * x0 + x2) / 2;
113 c = (x1 - xm1) / 2;
114 this->pOutputRight[i++] += effective_volume * ((((a * pos_fract) + b) * pos_fract + c) * pos_fract + x0);
115 #endif // USE_LINEAR_INTERPOLATION
116
117 this->Pos += this->CurrentPitch;
118 }
119 inline void InterpolateOneStep_Mono(sample_t* pSrc, int& i, float& effective_volume) {
120 int pos_int = double_to_int(this->Pos); // integer position
121 float pos_fract = this->Pos - pos_int; // fractional part of position
122
123 #if USE_LINEAR_INTERPOLATION
124 float sample_point = effective_volume * (pSrc[pos_int] + pos_fract * (pSrc[pos_int+1] - pSrc[pos_int]));
125 #else // polynomial interpolation
126 float xm1 = pSrc[pos_int];
127 float x0 = pSrc[pos_int+1];
128 float x1 = pSrc[pos_int+2];
129 float x2 = pSrc[pos_int+3];
130 float a = (3 * (x0 - x1) - xm1 + x2) / 2;
131 float b = 2 * x1 + xm1 - (5 * x0 + x2) / 2;
132 float c = (x1 - xm1) / 2;
133 float sample_point = effective_volume * ((((a * pos_fract) + b) * pos_fract + c) * pos_fract + x0);
134 #endif // USE_LINEAR_INTERPOLATION
135
136 this->pOutputLeft[i] += sample_point;
137 this->pOutputRight[i++] += sample_point;
138
139 this->Pos += this->CurrentPitch;
140 }
141 inline int double_to_int(double f) {
142 #if ARCH_X86
143 int i;
144 __asm__ ("fistl %0" : "=m"(i) : "st"(f - 0.5) );
145 return i;
146 #else
147 return (int) f;
148 #endif // ARCH_X86
149 }
150 };
151
152 #endif // __VOICE_H__

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