-
Notifications
You must be signed in to change notification settings - Fork 44
/
main.cpp
671 lines (532 loc) · 24.2 KB
/
main.cpp
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
570
571
572
573
574
575
576
577
578
579
580
581
582
583
584
585
586
587
588
589
590
591
592
593
594
595
596
597
598
599
600
601
602
603
604
605
606
607
608
609
610
611
612
613
614
615
616
617
618
619
620
621
622
623
624
625
626
627
628
629
630
631
632
633
634
635
636
637
638
639
640
641
642
643
644
645
646
647
648
649
650
651
652
653
654
655
656
657
658
659
660
661
662
663
664
665
666
667
668
669
670
671
/*
This file is part of Butterworth Filter Design, a pair C++ classes and an
accompanying suite of unit tests for designing high order Butterworth IIR &
EQ filters using the bilinear transform.
The generated filter coefficients are split out into cascaded biquad sections,
for easy use in your garden variety biquad or second-order section (SOS).
Reference: http://en.wikipedia.org/wiki/Butterworth_filter
http://www.musicdsp.org/files/Audio-EQ-Cookbook.txt
Copyright (C) 2013, iroro orife
This program is free software: you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
the Free Software Foundation, either version 3 of the License, or
(at your option) any later version.
This program is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
GNU General Public License for more details.
You should have received a copy of the GNU General Public License
along with this program. If not, see <http://www.gnu.org/licenses/>.
*/
#include <iostream>
#include <sndfile.hh>
#include "Butterworth.h"
#define CATCH_CONFIG_MAIN // Tells Catch to provide a main()
#include "catch.hpp" // Catch Unit test framework
using namespace std;
TEST_CASE("Analogue lowpass prototype generation", " Verify poles match MATLAB buttap(8)"){
//******************************************************************************
//
// baseline_poles values generated with MATLAB command >> buttap(8);
//
//******************************************************************************
int filterOrder = 8;
vector <complex_double> poles;
poles.resize(filterOrder);
vector <complex_double> baseline_poles;
baseline_poles.resize(filterOrder);
// Butterworth butter;
vector <complex_double> tempPoleStorage = Butterworth::prototypeAnalogLowPass(filterOrder);
// copy tmppole into poles
int index = 0;
for(vector <complex_double>::iterator itr = tempPoleStorage.begin(); itr != tempPoleStorage.end(); itr++){
poles[index] = *itr;
index++;
}
baseline_poles[0] = complex_double(-0.19509032201613, 0.98078528040323);
baseline_poles[1] = complex_double(-0.19509032201613, -0.98078528040323);
baseline_poles[2] = complex_double(-0.55557023301960, 0.83146961230255);
baseline_poles[3] = complex_double(-0.55557023301960, -0.83146961230255);
baseline_poles[4] = complex_double(-0.83146961230255, 0.55557023301960);
baseline_poles[5] = complex_double(-0.83146961230255, -0.55557023301960);
baseline_poles[6] = complex_double(-0.98078528040323, 0.19509032201613);
baseline_poles[7] = complex_double(-0.98078528040323, -0.19509032201613);
// Tolerance
const double EPSILON = 1.0e-14;
// Test
for(uint32_t i = 0; i < filterOrder; i++){
CAPTURE(i);
REQUIRE(abs(baseline_poles[i].real() - poles[i].real()) <= EPSILON);
}
}
TEST_CASE("Lowpass filter coefficients", " Verify coefficients for a lowpass filter"){
//******************************************************************************
// MATLAB (vR14) coefficients generated with the following code:
//
// [z, p, k] = butter(8, 500, 's');
// [Zd, Pd, Kd] = bilinear(z, p, k, 44100);
// [sos, g] = zpk2sos(Zd, Pd, Kd)
//******************************************************************************
int filterOrder = 8;
double overallGain = 1.0;
vector <Biquad> coeffs; // second-order sections (sos)
Butterworth butterworth;
bool designedCorrectly = butterworth.loPass(44100, // fs
500, // freq1
0, // freq2. N/A for lowpass
filterOrder,
coeffs,
overallGain);
REQUIRE(designedCorrectly == true);
//******************************************************************************
// MATLAB coefficients: first section
//******************************************************************************
double b0 = 1.0;
double b1 = 2.0;
double b2 = 1.0;
// double a0 = 1.0;
double a1 = -1.96762058043629 * (-1); // to convert to DF2T (direct form II transpose)
double a2 = 0.97261960500367 * (-1); // to convert to DF2T (direct form II transpose)
int i = 0;
const double EPSILON = 1.0e-4;
REQUIRE(abs(b0 - coeffs[i].b0) <= EPSILON);
REQUIRE(abs(b1 - coeffs[i].b1) <= EPSILON);
REQUIRE(abs(b2 - coeffs[i].b2) <= EPSILON);
REQUIRE(abs(a1 - coeffs[i].a1) <= EPSILON);
REQUIRE(abs(a2 - coeffs[i].a2) <= EPSILON);
//******************************************************************************
// MATLAB coefficients: second section
//******************************************************************************
b0 = 1.0;
b1 = 2.0;
b2 = 1.0;
// a0 = 1.0;
a1 = -1.91907529383978 * (-1);
a2 = 0.92395098208778 * (-1);
i = 1;
REQUIRE(abs(b0 - coeffs[i].b0) <= EPSILON);
REQUIRE(abs(b1 - coeffs[i].b1) <= EPSILON);
REQUIRE(abs(b2 - coeffs[i].b2) <= EPSILON);
REQUIRE(abs(a1 - coeffs[i].a1) <= EPSILON);
REQUIRE(abs(a2 - coeffs[i].a2) <= EPSILON);
//******************************************************************************
// MATLAB coefficients: third section
//******************************************************************************
b0 = 1.0;
b1 = 2.0;
b2 = 1.0;
// a0 = 1.0;
a1 = -1.88350864178159 * (-1);
a2 = 0.88829396780773 * (-1);
i = 2;
REQUIRE(abs(b0 - coeffs[i].b0) <= EPSILON);
REQUIRE(abs(b1 - coeffs[i].b1) <= EPSILON);
REQUIRE(abs(b2 - coeffs[i].b2) <= EPSILON);
REQUIRE(abs(a1 - coeffs[i].a1) <= EPSILON);
REQUIRE(abs(a2 - coeffs[i].a2) <= EPSILON);
//******************************************************************************
// MATLAB coefficients: fourth section
//******************************************************************************
b0 = 1.0;
b1 = 2.0;
b2 = 1.0;
// a0 = 1.0;
a1 = -1.86480445083537 * (-1);
a2 = 0.86954225616013 * (-1);
i = 3;
REQUIRE(abs(b0 - coeffs[i].b0) <= EPSILON);
REQUIRE(abs(b1 - coeffs[i].b1) <= EPSILON);
REQUIRE(abs(b2 - coeffs[i].b2) <= EPSILON);
REQUIRE(abs(a1 - coeffs[i].a1) <= EPSILON);
REQUIRE(abs(a2 - coeffs[i].a2) <= EPSILON);
}
TEST_CASE("Highpass filter coefficients", " Verify coefficients for a highpass filter"){
//******************************************************************************
// MATLAB (vR14) coefficients generated with the following code:
//
// [z, p, k] = butter(8, 500, 'high', 's');
// [Zd, Pd, Kd] = bilinear(z, p, k, 44100);
// [sos, g] = zpk2sos(Zd, Pd, Kd)
//******************************************************************************
int filterOrder = 8;
double overallGain = 1.0;
const double EPSILON = 1.0e-4;
vector <Biquad> coeffs; // second-order sections (sos)
Butterworth butterworth;
bool designedCorrectly = butterworth.hiPass(44100, // fs
500, // freq1
0, // freq2
filterOrder,
coeffs,
overallGain);
REQUIRE(designedCorrectly == true);
//******************************************************************************
// MATLAB coefficients: first section
//******************************************************************************
double b0 = 1.0;
double b1 = -2.0;
double b2 = 1.0;
// double a0 = 1.0;
double a1 = -1.96762058043629 * (-1);
double a2 = 0.97261960500367 * (-1);
int i = 0;
REQUIRE(abs(b0 - coeffs[i].b0) <= EPSILON);
REQUIRE(abs(b1 - coeffs[i].b1) <= EPSILON);
REQUIRE(abs(b2 - coeffs[i].b2) <= EPSILON);
REQUIRE(abs(a1 - coeffs[i].a1) <= EPSILON);
REQUIRE(abs(a2 - coeffs[i].a2) <= EPSILON);
//******************************************************************************
// MATLAB coefficients: second section
//******************************************************************************
b0 = 1.0;
b1 = -2.0;
b2 = 1.0;
// a0 = 1.0;
a1 = -1.91907529383978 * (-1);
a2 = 0.92395098208778 * (-1);
i = 1;
REQUIRE(abs(b0 - coeffs[i].b0) <= EPSILON);
REQUIRE(abs(b1 - coeffs[i].b1) <= EPSILON);
REQUIRE(abs(b2 - coeffs[i].b2) <= EPSILON);
REQUIRE(abs(a1 - coeffs[i].a1) <= EPSILON);
REQUIRE(abs(a2 - coeffs[i].a2) <= EPSILON);
//******************************************************************************
// MATLAB coefficients: third section
//******************************************************************************
b0 = 1.0;
b1 = -2.0;
b2 = 1.0;
// a0 = 1.0;
a1 = -1.88350864178159 * (-1);
a2 = 0.88829396780773 * (-1);
i = 2;
REQUIRE(abs(b0 - coeffs[i].b0) <= EPSILON);
REQUIRE(abs(b1 - coeffs[i].b1) <= EPSILON);
REQUIRE(abs(b2 - coeffs[i].b2) <= EPSILON);
REQUIRE(abs(a1 - coeffs[i].a1) <= EPSILON);
REQUIRE(abs(a2 - coeffs[i].a2) <= EPSILON);
//******************************************************************************
// MATLAB coefficients: fourth section
//******************************************************************************
b0 = 1.0;
b1 = -2.0;
b2 = 1.0;
// a0 = 1.0;
a1 = -1.86480445083537 * (-1);
a2 = 0.86954225616013 * (-1);
i = 3;
REQUIRE(abs(b0 - coeffs[i].b0) <= EPSILON);
REQUIRE(abs(b1 - coeffs[i].b1) <= EPSILON);
REQUIRE(abs(b2 - coeffs[i].b2) <= EPSILON);
REQUIRE(abs(a1 - coeffs[i].a1) <= EPSILON);
REQUIRE(abs(a2 - coeffs[i].a2) <= EPSILON);
}
TEST_CASE("Parametric EQ coefficients", " Verify coefficients for a parametric filter"){
//******************************************************************************
// MATLAB coefficients were generated with the following code in
// MATLAB R14 with code hpeq1.m from
//
// Reference: Sophocles J. Orfanidis, "High-Order Digital Parametric Equalizer
// Design," J. Audio Eng. Soc., vol.53, pp. 1026-1046, November 2005.
//******************************************************************************
int filterOrder = 8;
double overallGain = 12.0;
const double EPSILON = 1.0e-4;
vector <Biquad> coeffs;
Butterworth butterworth;
bool designedCorrectly = butterworth.coefficientsEQ(Butterworth::kParametric,
40000, // fs
3500, // freq1
6500, // freq2 Df = 3kHz
filterOrder,
coeffs,
overallGain);
REQUIRE(designedCorrectly == true);
//******************************************************************************
// MATLAB coefficients: first section
//******************************************************************************
double b0 = 1.0356;
double b1 = -2.6699;
double b2 = 3.4403;
double b3 = -2.3905;
double b4 = 0.8435;
// double a0 = 1.0;
double a1 = -2.6478 * (-1);
double a2 = 3.4810 * (-1);
double a3 = -2.4127 * (-1);
double a4 = 0.8384 * (-1);
int i = 0;
REQUIRE(abs(b0 - coeffs[i].b0) <= EPSILON);
REQUIRE(abs(b1 - coeffs[i].b1) <= EPSILON);
REQUIRE(abs(b2 - coeffs[i].b2) <= EPSILON);
REQUIRE(abs(b3 - coeffs[i].b3) <= EPSILON);
REQUIRE(abs(b4 - coeffs[i].b4) <= EPSILON);
REQUIRE(abs(a1 - coeffs[i].a1) <= EPSILON);
REQUIRE(abs(a2 - coeffs[i].a2) <= EPSILON);
REQUIRE(abs(a3 - coeffs[i].a3) <= EPSILON);
REQUIRE(abs(a4 - coeffs[i].a4) <= EPSILON);
//******************************************************************************
// MATLAB coefficients: second section
//******************************************************************************
b0 = 1.0555;
b1 = -2.5476;
b2 = 2.9933;
b3 = -1.8553;
b4 = 0.5794;
// a0 = 1.0;
a1 = -2.4927 * (-1);
a2 = 3.0287 * (-1);
a3 = -1.9102 * (-1);
a4 = 0.5995 * (-1);
i = 1;
REQUIRE(abs(b0 - coeffs[i].b0) <= EPSILON);
REQUIRE(abs(b1 - coeffs[i].b1) <= EPSILON);
REQUIRE(abs(b2 - coeffs[i].b2) <= EPSILON);
REQUIRE(abs(b3 - coeffs[i].b3) <= EPSILON);
REQUIRE(abs(b4 - coeffs[i].b4) <= EPSILON);
REQUIRE(abs(a1 - coeffs[i].a1) <= EPSILON);
REQUIRE(abs(a2 - coeffs[i].a2) <= EPSILON);
REQUIRE(abs(a3 - coeffs[i].a3) <= EPSILON);
REQUIRE(abs(a4 - coeffs[i].a4) <= EPSILON);
}
TEST_CASE("Low shelf EQ coefficients", " Verify coefficients for a low shelf filter"){
//******************************************************************************
// MATLAB coefficients were generated with the following code in
// MATLAB R14 with code hpeq1.m from
//
// Reference: Sophocles J. Orfanidis, "High-Order Digital Parametric Equalizer
// Design," J. Audio Eng. Soc., vol.53, pp. 1026-1046, November 2005.
//******************************************************************************
int filterOrder = 4;
double overallGain = 12.0;
const double EPSILON = 1.0e-4;
vector <Biquad> coeffs; // second-order sections (sos)
Butterworth butterworth;
bool designedCorrectly = butterworth.coefficientsEQ(Butterworth::kLoShelf,
40000, // fs
0, // freq1
13000, // freq2 Df = 13kHz
filterOrder,
coeffs,
overallGain);
REQUIRE(designedCorrectly == true);
//******************************************************************************
// MATLAB coefficients: first section
//******************************************************************************
double b0 = 1.6392;
double b1 = 1.7241;
double b2 = 0.9170;
// double a0 = 1.0;
double a1 = 0.6565 * (-1);
double a2 = 0.4887 * (-1);
int i = 0;
REQUIRE(abs(b0 - coeffs[i].b0) <= EPSILON);
REQUIRE(abs(b1 - coeffs[i].b1) <= EPSILON);
REQUIRE(abs(b2 - coeffs[i].b2) <= EPSILON);
REQUIRE(abs(a1 - coeffs[i].a1) <= EPSILON);
REQUIRE(abs(a2 - coeffs[i].a2) <= EPSILON);
//******************************************************************************
// MATLAB coefficients: second section
//******************************************************************************
b0 = 1.5790;
b1 = 1.2663;
b2 = 0.2984;
// a0 = 1.0;
a1 = 0.4822 * (-1);
a2 = 0.0934 * (-1);
i = 1;
REQUIRE(abs(b0 - coeffs[i].b0) <= EPSILON);
REQUIRE(abs(b1 - coeffs[i].b1) <= EPSILON);
REQUIRE(abs(b2 - coeffs[i].b2) <= EPSILON);
REQUIRE(abs(a1 - coeffs[i].a1) <= EPSILON);
REQUIRE(abs(a2 - coeffs[i].a2) <= EPSILON);
//******************************************************************************
// test another set of lowshelf design requirements
//******************************************************************************
designedCorrectly = butterworth.coefficientsEQ(Butterworth::kLoShelf,
40000, // fs
2000, // freq1
2800, // freq2 Df = 0.8kHz
filterOrder,
coeffs,
overallGain);
REQUIRE(designedCorrectly == true);
//******************************************************************************
// MATLAB coefficients: first section
//******************************************************************************
b0 = 1.0222;
b1 = -1.8880;
b2 = 0.8949;
// a0 = 1.0;
a1 = -1.8953 * (-1);
a2 = 0.9099 * (-1);
i = 0;
REQUIRE(abs(b0 - coeffs[i].b0) <= EPSILON);
REQUIRE(abs(b1 - coeffs[i].b1) <= EPSILON);
REQUIRE(abs(b2 - coeffs[i].b2) <= EPSILON);
REQUIRE(abs(a1 - coeffs[i].a1) <= EPSILON);
REQUIRE(abs(a2 - coeffs[i].a2) <= EPSILON);
//******************************************************************************
// MATLAB coefficients: second section
//******************************************************************************
b0 = 1.0456;
b1 = -1.7749;
b2 = 0.7566;
// a0 = 1.0;
a1 = -1.7817 * (-1);
a2 = 0.7954 * (-1);
i = 1;
REQUIRE(abs(b0 - coeffs[i].b0) <= EPSILON);
REQUIRE(abs(b1 - coeffs[i].b1) <= EPSILON);
REQUIRE(abs(b2 - coeffs[i].b2) <= EPSILON);
REQUIRE(abs(a1 - coeffs[i].a1) <= EPSILON);
REQUIRE(abs(a2 - coeffs[i].a2) <= EPSILON);
}
//-------------------------------------------------------------------------------------------------
TEST_CASE("High shelf EQ coefficients", " Verify coefficients for a high shelf filter"){
//******************************************************************************
// MATLAB coefficients were generated with the following code in
// MATLAB R14 with code hpeq1.m from
//
// Reference: Sophocles J. Orfanidis, "High-Order Digital Parametric Equalizer
// Design," J. Audio Eng. Soc., vol.53, pp. 1026-1046, November 2005.
//******************************************************************************
int filterOrder = 4;
double overallGain = 12.0;
const double EPSILON = 1.0e-4;
vector <Biquad> coeffs; // second-order sections (sos)
Butterworth butterworth;
bool designedCorrectly = butterworth.coefficientsEQ(Butterworth::kHiShelf,
40000, // fs
0, // freq1
13000, // freq2 Df = 13kHz
filterOrder,
coeffs,
overallGain);
REQUIRE(designedCorrectly == true);
//******************************************************************************
// MATLAB coefficients: first section
//******************************************************************************
double b0 = 1.6392;
double b1 = -1.7241;
double b2 = 0.9170;
// double a0 = 1.0;
double a1 = -0.6565 * (-1);
double a2 = 0.4887 * (-1);
int i = 0;
REQUIRE(abs(b0 - coeffs[i].b0) <= EPSILON);
REQUIRE(abs(b1 - coeffs[i].b1) <= EPSILON);
REQUIRE(abs(b2 - coeffs[i].b2) <= EPSILON);
REQUIRE(abs(a1 - coeffs[i].a1) <= EPSILON);
REQUIRE(abs(a2 - coeffs[i].a2) <= EPSILON);
//******************************************************************************
// MATLAB coefficients: second section
//******************************************************************************
b0 = 1.5790;
b1 = -1.2663;
b2 = 0.2984;
// a0 = 1.0;
a1 = -0.4822 * (-1);
a2 = 0.0934 * (-1);
i = 1;
REQUIRE(abs(b0 - coeffs[i].b0) <= EPSILON);
REQUIRE(abs(b1 - coeffs[i].b1) <= EPSILON);
REQUIRE(abs(b2 - coeffs[i].b2) <= EPSILON);
REQUIRE(abs(a1 - coeffs[i].a1) <= EPSILON);
REQUIRE(abs(a2 - coeffs[i].a2) <= EPSILON);
//******************************************************************************
// test another set of highshelf design requirements
//******************************************************************************
designedCorrectly = butterworth.coefficientsEQ(Butterworth::kHiShelf,
40000, // fs
2000, // freq1
2800, // freq2 Df = 13kHz
filterOrder,
coeffs,
overallGain);
REQUIRE(designedCorrectly == true);
//******************************************************************************
// MATLAB coefficients: first section
//******************************************************************************
b0 = 1.0222;
b1 = 1.8880;
b2 = 0.8949;
// a0 = 1.0;
a1 = 1.8953 * (-1);
a2 = 0.9099 * (-1);
i = 0;
REQUIRE(abs(b0 - coeffs[i].b0) <= EPSILON);
REQUIRE(abs(b1 - coeffs[i].b1) <= EPSILON);
REQUIRE(abs(b2 - coeffs[i].b2) <= EPSILON);
REQUIRE(abs(a1 - coeffs[i].a1) <= EPSILON);
REQUIRE(abs(a2 - coeffs[i].a2) <= EPSILON);
//******************************************************************************
// MATLAB coefficients: second section
//******************************************************************************
b0 = 1.0456;
b1 = 1.7749;
b2 = 0.7566;
// a0 = 1.0;
a1 = 1.7817 * (-1);
a2 = 0.7954 * (-1);
i = 1;
REQUIRE(abs(b0 - coeffs[i].b0) <= EPSILON);
REQUIRE(abs(b1 - coeffs[i].b1) <= EPSILON);
REQUIRE(abs(b2 - coeffs[i].b2) <= EPSILON);
REQUIRE(abs(a1 - coeffs[i].a1) <= EPSILON);
REQUIRE(abs(a2 - coeffs[i].a2) <= EPSILON);
}
//-------------------------------------------------------------------------------------------------
#define BUFFER_LEN 1024
#define MAX_CHANNELS 6
static void process_data (double *data, int count, int channels)
{
int k;
/* Process the data here.
** If the soundfile contains more then 1 channel you need to take care of
** the data interleaving youself.
** Current we just apply a channel dependant gain.
*/
for (k = 0 ; k < count ; k+= 1)
data [k] *= 1.0;
return ;
}
static void read_write_file (const char *infilename, const char *outfilename)
{
static double data [BUFFER_LEN] ;
SNDFILE *infile, *outfile ;
SF_INFO sfinfo ;
int readcount ;
memset (&sfinfo, 0, sizeof (sfinfo)) ;
if (! (infile = sf_open (infilename, SFM_READ, &sfinfo)))
{
printf ("Not able to open input file %s.\n", infilename) ;
puts (sf_strerror (NULL)) ;
return;
}
if (sfinfo.channels > MAX_CHANNELS)
{ printf ("Not able to process more than %d channels\n", MAX_CHANNELS) ;
return;
}
if (! (outfile = sf_open (outfilename, SFM_WRITE, &sfinfo)))
{ printf ("Not able to open output file %s.\n", outfilename) ;
puts (sf_strerror (NULL)) ;
return;
}
while ((readcount = sf_read_double (infile, data, BUFFER_LEN)))
{ process_data (data, readcount, sfinfo.channels) ;
sf_write_double (outfile, data, readcount) ;
}
sf_close (infile); sf_close (outfile) ;
return;
}
TEST_CASE("Test gain control issue #3"){
//******************************************************************************
// For this test you will need libsndfile.a which lives in
// /opt/local/lib/libsndfile.a installed on MacOS via macports
// https://trac.macports.org/browser/trunk/dports/audio/libsndfile/Portfile
//******************************************************************************
const char * infilename = "sweep_0_20K.wav" ;
const char * outfilename = "sweep_0_20K_filtered.wav" ;
read_write_file(infilename,outfilename);
}