Jack2: JackFilters.h Source File

Jack2 1.9.12

JackFilters.h
1 /*
2 Copyright (C) 2008 Grame
3
4 This program is free software; you can redistribute it and/or modify
5 it under the terms of the GNU General Public License as published by
6 the Free Software Foundation; either version 2 of the License, or
7 (at your option) any later version.
8
9 This program is distributed in the hope that it will be useful,
10 but WITHOUT ANY WARRANTY; without even the implied warranty of
11 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
12 GNU General Public License for more details.
13
14 You should have received a copy of the GNU General Public License
15 along with this program; if not, write to the Free Software
16 Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
17
18 */
19
20 #ifndef __JackFilters__
21 #define __JackFilters__
22
23 #ifdef __APPLE__
24 #include <TargetConditionals.h>
25 #endif
26
27 #include "jack.h"
28 #ifndef MY_TARGET_OS_IPHONE
29 #include "JackAtomicState.h"
30 #endif
31 #include <math.h>
32 #include <stdlib.h>
33
34 namespace Jack
35 {
36
37 #ifndef TARGET_OS_IPHONE
38
39 #define MAX_SIZE 64
40
41 PRE_PACKED_STRUCTURE
42 struct JackFilter
43 {
44
45 jack_time_t fTable[MAX_SIZE];
46
47 JackFilter()
48 {
49 for (int i = 0; i < MAX_SIZE; i++) {
50 fTable[i] = 0;
51 }
52 }
53
54 void AddValue(jack_time_t val)
55 {
56 memcpy(&fTable[1], &fTable[0], sizeof(jack_time_t) * (MAX_SIZE - 1));
57 fTable[0] = val;
58 }
59
60 jack_time_t GetVal()
61 {
62 jack_time_t mean = 0;
63 for (int i = 0; i < MAX_SIZE; i++) {
64 mean += fTable[i];
65 }
66 return mean / MAX_SIZE;
67 }
68
69 } POST_PACKED_STRUCTURE;
70
71 PRE_PACKED_STRUCTURE
72 class JackDelayLockedLoop
73 {
74
75 private:
76
77 jack_nframes_t fFrames;
78 jack_time_t fCurrentWakeup;
79 jack_time_t fCurrentCallback;
80 jack_time_t fNextWakeUp;
81 float fSecondOrderIntegrator;
82 jack_nframes_t fBufferSize;
83 jack_nframes_t fSampleRate;
84 jack_time_t fPeriodUsecs;
85 float fFilterCoefficient; /* set once, never altered */
86 bool fUpdating;
87
88 public:
89
90 JackDelayLockedLoop()
91 {}
92
93 JackDelayLockedLoop(jack_nframes_t buffer_size, jack_nframes_t sample_rate)
94 {
95 Init(buffer_size, sample_rate);
96 }
97
98 void Init(jack_nframes_t buffer_size, jack_nframes_t sample_rate)
99 {
100 fFrames = 0;
101 fCurrentWakeup = 0;
102 fCurrentCallback = 0;
103 fNextWakeUp = 0;
104 fFilterCoefficient = 0.01f;
105 fSecondOrderIntegrator = 0.0f;
106 fBufferSize = buffer_size;
107 fSampleRate = sample_rate;
108 fPeriodUsecs = jack_time_t(1000000.f / fSampleRate * fBufferSize); // in microsec
109 }
110
111 void Init(jack_time_t callback_usecs)
112 {
113 fFrames = 0;
114 fCurrentWakeup = 0;
115 fSecondOrderIntegrator = 0.0f;
116 fCurrentCallback = callback_usecs;
117 fNextWakeUp = callback_usecs + fPeriodUsecs;
118 }
119
120 void IncFrame(jack_time_t callback_usecs)
121 {
122 float delta = (int64_t)callback_usecs - (int64_t)fNextWakeUp;
123 fCurrentWakeup = fNextWakeUp;
124 fCurrentCallback = callback_usecs;
125 fFrames += fBufferSize;
126 fSecondOrderIntegrator += 0.5f * fFilterCoefficient * delta;
127 fNextWakeUp = fCurrentWakeup + fPeriodUsecs + (int64_t) floorf((fFilterCoefficient * (delta + fSecondOrderIntegrator)));
128 }
129
130 jack_nframes_t Time2Frames(jack_time_t time)
131 {
132 long delta = (long) rint(((double) ((long long)(time - fCurrentWakeup)) / ((long long)(fNextWakeUp - fCurrentWakeup))) * fBufferSize);
133 return (delta < 0) ? ((fFrames > 0) ? fFrames : 1) : (fFrames + delta);
134 }
135
136 jack_time_t Frames2Time(jack_nframes_t frames)
137 {
138 long delta = (long) rint(((double) ((long long)(frames - fFrames)) * ((long long)(fNextWakeUp - fCurrentWakeup))) / fBufferSize);
139 return (delta < 0) ? ((fCurrentWakeup > 0) ? fCurrentWakeup : 1) : (fCurrentWakeup + delta);
140 }
141
142 jack_nframes_t CurFrame()
143 {
144 return fFrames;
145 }
146
147 jack_time_t CurTime()
148 {
149 return fCurrentWakeup;
150 }
151
152 } POST_PACKED_STRUCTURE;
153
154 PRE_PACKED_STRUCTURE
155 class JackAtomicDelayLockedLoop : public JackAtomicState<JackDelayLockedLoop>
156 {
157 public:
158
159 JackAtomicDelayLockedLoop(jack_nframes_t buffer_size, jack_nframes_t sample_rate)
160 {
161 fState[0].Init(buffer_size, sample_rate);
162 fState[1].Init(buffer_size, sample_rate);
163 }
164
165 void Init(jack_time_t callback_usecs)
166 {
167 JackDelayLockedLoop* dll = WriteNextStateStart();
168 dll->Init(callback_usecs);
169 WriteNextStateStop();
170 TrySwitchState(); // always succeed since there is only one writer
171 }
172
173 void Init(jack_nframes_t buffer_size, jack_nframes_t sample_rate)
174 {
175 JackDelayLockedLoop* dll = WriteNextStateStart();
176 dll->Init(buffer_size, sample_rate);
177 WriteNextStateStop();
178 TrySwitchState(); // always succeed since there is only one writer
179 }
180
181 void IncFrame(jack_time_t callback_usecs)
182 {
183 JackDelayLockedLoop* dll = WriteNextStateStart();
184 dll->IncFrame(callback_usecs);
185 WriteNextStateStop();
186 TrySwitchState(); // always succeed since there is only one writer
187 }
188
189 jack_nframes_t Time2Frames(jack_time_t time)
190 {
191 UInt16 next_index = GetCurrentIndex();
192 UInt16 cur_index;
193 jack_nframes_t res;
194
195 do {
196 cur_index = next_index;
197 res = ReadCurrentState()->Time2Frames(time);
198 next_index = GetCurrentIndex();
199 } while (cur_index != next_index); // Until a coherent state has been read
200
201 return res;
202 }
203
204 jack_time_t Frames2Time(jack_nframes_t frames)
205 {
206 UInt16 next_index = GetCurrentIndex();
207 UInt16 cur_index;
208 jack_time_t res;
209
210 do {
211 cur_index = next_index;
212 res = ReadCurrentState()->Frames2Time(frames);
213 next_index = GetCurrentIndex();
214 } while (cur_index != next_index); // Until a coherent state has been read
215
216 return res;
217 }
218 } POST_PACKED_STRUCTURE;
219
220 #endif
221
222 /*
223 Torben Hohn PI controler from JACK1
224 */
225
226 struct JackPIControler {
227
228 double resample_mean;
229 double static_resample_factor;
230
231 double* offset_array;
232 double* window_array;
233 int offset_differential_index;
234
235 double offset_integral;
236
237 double catch_factor;
238 double catch_factor2;
239 double pclamp;
240 double controlquant;
241 int smooth_size;
242
243 double hann(double x)
244 {
245 return 0.5 * (1.0 - cos(2 * M_PI * x));
246 }
247
248 JackPIControler(double resample_factor, int fir_size)
249 {
250 resample_mean = resample_factor;
251 static_resample_factor = resample_factor;
252 offset_array = new double[fir_size];
253 window_array = new double[fir_size];
254 offset_differential_index = 0;
255 offset_integral = 0.0;
256 smooth_size = fir_size;
257
258 for (int i = 0; i < fir_size; i++) {
259 offset_array[i] = 0.0;
260 window_array[i] = hann(double(i) / (double(fir_size) - 1.0));
261 }
262
263 // These values could be configurable
264 catch_factor = 100000;
265 catch_factor2 = 10000;
266 pclamp = 15.0;
267 controlquant = 10000.0;
268 }
269
270 ~JackPIControler()
271 {
272 delete[] offset_array;
273 delete[] window_array;
274 }
275
276 void Init(double resample_factor)
277 {
278 resample_mean = resample_factor;
279 static_resample_factor = resample_factor;
280 }
281
282 /*
283 double GetRatio(int fill_level)
284 {
285 double offset = fill_level;
286
287 // Save offset.
288 offset_array[(offset_differential_index++) % smooth_size] = offset;
289
290 // Build the mean of the windowed offset array basically fir lowpassing.
291 double smooth_offset = 0.0;
292 for (int i = 0; i < smooth_size; i++) {
293 smooth_offset += offset_array[(i + offset_differential_index - 1) % smooth_size] * window_array[i];
294 }
295 smooth_offset /= double(smooth_size);
296
297 // This is the integral of the smoothed_offset
298 offset_integral += smooth_offset;
299
300 // Clamp offset : the smooth offset still contains unwanted noise which would go straigth onto the resample coeff.
301 // It only used in the P component and the I component is used for the fine tuning anyways.
302 if (fabs(smooth_offset) < pclamp)
303 smooth_offset = 0.0;
304
305 // Ok, now this is the PI controller.
306 // u(t) = K * (e(t) + 1/T \int e(t') dt')
307 // Kp = 1/catch_factor and T = catch_factor2 Ki = Kp/T
308 double current_resample_factor
309 = static_resample_factor - smooth_offset / catch_factor - offset_integral / catch_factor / catch_factor2;
310
311 // Now quantize this value around resample_mean, so that the noise which is in the integral component doesnt hurt.
312 current_resample_factor = floor((current_resample_factor - resample_mean) * controlquant + 0.5) / controlquant + resample_mean;
313
314 // Calculate resample_mean so we can init ourselves to saner values.
315 resample_mean = 0.9999 * resample_mean + 0.0001 * current_resample_factor;
316 return current_resample_factor;
317 }
318 */
319
320 double GetRatio(int error)
321 {
322 double smooth_offset = error;
323
324 // This is the integral of the smoothed_offset
325 offset_integral += smooth_offset;
326
327 // Ok, now this is the PI controller.
328 // u(t) = K * (e(t) + 1/T \int e(t') dt')
329 // Kp = 1/catch_factor and T = catch_factor2 Ki = Kp/T
330 return static_resample_factor - smooth_offset/catch_factor - offset_integral/catch_factor/catch_factor2;
331 }
332
333 void OurOfBounds()
334 {
335 int i;
336 // Set the resample_rate... we need to adjust the offset integral, to do this.
337 // first look at the PI controller, this code is just a special case, which should never execute once
338 // everything is swung in.
339 offset_integral = - (resample_mean - static_resample_factor) * catch_factor * catch_factor2;
340 // Also clear the array. we are beginning a new control cycle.
341 for (i = 0; i < smooth_size; i++) {
342 offset_array[i] = 0.0;
343 }
344 }
345
346 };
347
348 }
349
350 #endif
Jack::JackAtomicState
A class to handle two states (switching from one to the other) in a lock-free manner.
Definition: JackAtomicState.h:90
Jack::JackDelayLockedLoop
Definition: JackFilters.h:72
Jack::JackAtomicState< JackDelayLockedLoop >::ReadCurrentState
JackDelayLockedLoop * ReadCurrentState()
Returns the current state : only valid in the RT reader thread.
Definition: JackAtomicState.h:144
Jack::JackFilter
Definition: JackFilters.h:42
Jack::JackAtomicState< JackDelayLockedLoop >::GetCurrentIndex
UInt16 GetCurrentIndex()
Returns the current state index.
Definition: JackAtomicState.h:152
Jack::JackAtomicDelayLockedLoop
Definition: JackFilters.h:155
Jack::JackAtomicState< JackDelayLockedLoop >::WriteNextStateStart
JackDelayLockedLoop * WriteNextStateStart()
Start write operation : setup and returns the next state to update, check for recursive write calls.
Definition: JackAtomicState.h:191
Jack::JackAtomicState< JackDelayLockedLoop >::TrySwitchState
JackDelayLockedLoop * TrySwitchState()
Tries to switch to the next state and returns the new current state (either the same as before if cas...
Definition: JackAtomicState.h:160
Jack::JackPIControler
Definition: JackFilters.h:226
Jack::JackAtomicState< JackDelayLockedLoop >::WriteNextStateStop
void WriteNextStateStop()
Stop write operation : make the next state ready to be used by the RT thread.
Definition: JackAtomicState.h:202