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

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Revision 30 - (show annotations) (download) (as text)
Sun Jan 11 16:43:54 2004 UTC (20 years, 3 months ago) by schoenebeck
File MIME type: text/x-c++hdr
File size: 8684 byte(s)
* implemented amplitude envelope generator
* src/voice.cpp: some .gig instruments still sounded detuned, I hope
  finally to have this fixed now

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 RenderAudio();
49 int Trigger(int MIDIKey, uint8_t Velocity, gig::Instrument* Instrument);
50 inline bool IsActive() { return Active; }
51 inline void SetOutput(float* pOutput, uint OutputBufferSize) { this->pOutput = pOutput; this->OutputBufferSize = OutputBufferSize; }
52 private:
53 // Types
54 enum playback_state_t {
55 playback_state_ram,
56 playback_state_disk,
57 playback_state_end
58 };
59
60 // Attributes
61 float Volume; ///< Volume level of the voice
62 float* pOutput; ///< Audio output buffer
63 uint OutputBufferSize; ///< Fragment size of the audio output buffer
64 double Pos; ///< Current playback position in sample
65 double CurrentPitch; ///< Current pitch depth (number of sample points to move on with each render step)
66 gig::Sample* pSample; ///< Pointer to the sample to be played back
67 gig::Region* pRegion; ///< Pointer to the articulation information of the respective keyboard region of this voice
68 bool Active; ///< If this voice object is currently in usage
69 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
70 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
71 Stream::reference_t DiskStreamRef; ///< Reference / link to the disk stream
72 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.
73 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
74 int LoopCyclesLeft; ///< In case there is a RAMLoop and it's not an endless loop; reflects number of loop cycles left to be passed
75 EG_VCA EG1;
76
77 // Static Attributes
78 static DiskThread* pDiskThread; ///< Pointer to the disk thread, to be able to order a disk stream and later to delete the stream again
79
80 // Methods
81 void Interpolate(sample_t* pSrc);
82 void InterpolateAndLoop(sample_t* pSrc);
83 inline void InterpolateOneStep_Stereo(sample_t* pSrc, int& i, float& effective_volume) {
84 int pos_int = double_to_int(this->Pos); // integer position
85 float pos_fract = this->Pos - pos_int; // fractional part of position
86 pos_int <<= 1;
87
88 #if USE_LINEAR_INTERPOLATION
89 // left channel
90 this->pOutput[i++] += effective_volume * (pSrc[pos_int] + pos_fract * (pSrc[pos_int+2] - pSrc[pos_int]));
91 // right channel
92 this->pOutput[i++] += effective_volume * (pSrc[pos_int+1] + pos_fract * (pSrc[pos_int+3] - pSrc[pos_int+1]));
93 #else // polynomial interpolation
94 // calculate left channel
95 float xm1 = pSrc[pos_int];
96 float x0 = pSrc[pos_int+2];
97 float x1 = pSrc[pos_int+4];
98 float x2 = pSrc[pos_int+6];
99 float a = (3 * (x0 - x1) - xm1 + x2) / 2;
100 float b = 2 * x1 + xm1 - (5 * x0 + x2) / 2;
101 float c = (x1 - xm1) / 2;
102 this->pOutput[i++] += effective_volume * ((((a * pos_fract) + b) * pos_fract + c) * pos_fract + x0);
103
104 //calculate right channel
105 xm1 = pSrc[pos_int+1];
106 x0 = pSrc[pos_int+3];
107 x1 = pSrc[pos_int+5];
108 x2 = pSrc[pos_int+7];
109 a = (3 * (x0 - x1) - xm1 + x2) / 2;
110 b = 2 * x1 + xm1 - (5 * x0 + x2) / 2;
111 c = (x1 - xm1) / 2;
112 this->pOutput[i++] += effective_volume * ((((a * pos_fract) + b) * pos_fract + c) * pos_fract + x0);
113 #endif // USE_LINEAR_INTERPOLATION
114
115 this->Pos += this->CurrentPitch;
116 }
117 inline void InterpolateOneStep_Mono(sample_t* pSrc, int& i, float& effective_volume) {
118 int pos_int = double_to_int(this->Pos); // integer position
119 float pos_fract = this->Pos - pos_int; // fractional part of position
120
121 #if USE_LINEAR_INTERPOLATION
122 float sample_point = effective_volume * (pSrc[pos_int] + pos_fract * (pSrc[pos_int+1] - pSrc[pos_int]));
123 #else // polynomial interpolation
124 float xm1 = pSrc[pos_int];
125 float x0 = pSrc[pos_int+1];
126 float x1 = pSrc[pos_int+2];
127 float x2 = pSrc[pos_int+3];
128 float a = (3 * (x0 - x1) - xm1 + x2) / 2;
129 float b = 2 * x1 + xm1 - (5 * x0 + x2) / 2;
130 float c = (x1 - xm1) / 2;
131 float sample_point = effective_volume * ((((a * pos_fract) + b) * pos_fract + c) * pos_fract + x0);
132 #endif // USE_LINEAR_INTERPOLATION
133
134 this->pOutput[i++] += sample_point;
135 this->pOutput[i++] += sample_point;
136
137 this->Pos += this->CurrentPitch;
138 }
139 inline int double_to_int(double f) {
140 #if ARCH_X86
141 int i;
142 __asm__ ("fistl %0" : "=m"(i) : "st"(f - 0.5) );
143 return i;
144 #else
145 return (int) f;
146 #endif // ARCH_X86
147 }
148 };
149
150 #endif // __VOICE_H__

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