/
resample.c
613 lines (537 loc) · 14.6 KB
1
/*
2
3
4
5
6
TiMidity -- Experimental MIDI to WAVE converter
Copyright (C) 1995 Tuukka Toivonen <toivonen@clinet.fi>
This program is free software; you can redistribute it and/or modify
7
it under the terms of the Perl Artistic License, available in COPYING.
8
9
10
11
12
13
14
resample.c
*/
#if HAVE_CONFIG_H
# include <config.h>
#endif
15
16
17
#include <math.h>
#include <stdio.h>
18
#include <stdlib.h>
19
20
21
22
23
#include "SDL.h"
#include "timidity.h"
#include "options.h"
24
25
26
27
28
29
#include "common.h"
#include "instrum.h"
#include "playmidi.h"
#include "tables.h"
#include "resample.h"
30
31
#define PRECALC_LOOP_COUNT(start, end, incr) (((end) - (start) + (incr) - 1) / (incr))
32
33
/*************** resampling with fixed increment *****************/
34
static sample_t *rs_plain(MidiSong *song, int v, Sint32 *countptr)
35
36
37
38
{
/* Play sample until end, then free the voice. */
39
sample_t v1, v2;
40
Voice
41
*vp=&(song->voice[v]);
42
sample_t
43
*dest=song->resample_buffer,
44
*src=vp->sample->data;
45
Sint32
46
47
48
49
ofs=vp->sample_offset,
incr=vp->sample_increment,
le=vp->sample->data_length,
count=*countptr;
50
Sint32 i, j;
51
52
53
54
55
if (incr<0) incr = -incr; /* In case we're coming out of a bidir loop */
/* Precalc how many times we should go through the loop.
NOTE: Assumes that incr > 0 and that ofs <= le */
56
i = PRECALC_LOOP_COUNT(ofs, le, incr);
57
58
59
60
61
62
63
64
if (i > count)
{
i = count;
count = 0;
}
else count -= i;
65
for (j = 0; j < i; j++)
66
{
67
68
69
v1 = src[ofs >> FRACTION_BITS];
v2 = src[(ofs >> FRACTION_BITS)+1];
*dest++ = v1 + (((v2 - v1) * (ofs & FRACTION_MASK)) >> FRACTION_BITS);
70
71
72
73
74
ofs += incr;
}
if (ofs >= le)
{
75
if (ofs == le)
76
*dest++ = src[(ofs>>FRACTION_BITS)-1]/2;
77
78
79
80
81
vp->status=VOICE_FREE;
*countptr-=count+1;
}
vp->sample_offset=ofs; /* Update offset */
82
return song->resample_buffer;
83
84
}
85
static sample_t *rs_loop(MidiSong *song, Voice *vp, Sint32 count)
86
87
88
89
{
/* Play sample until end-of-loop, skip back and continue. */
90
91
sample_t v1, v2;
Sint32
92
93
94
95
96
ofs=vp->sample_offset,
incr=vp->sample_increment,
le=vp->sample->loop_end,
ll=le - vp->sample->loop_start;
sample_t
97
*dest=song->resample_buffer,
98
*src=vp->sample->data;
99
Sint32 i, j;
100
101
102
while (count)
{
103
while (ofs >= le)
104
105
ofs -= ll;
/* Precalc how many times we should go through the loop */
106
i = PRECALC_LOOP_COUNT(ofs, le, incr);
107
108
109
110
111
112
if (i > count)
{
i = count;
count = 0;
}
else count -= i;
113
for (j = 0; j < i; j++)
114
{
115
116
117
v1 = src[ofs >> FRACTION_BITS];
v2 = src[(ofs >> FRACTION_BITS)+1];
*dest++ = v1 + (((v2 - v1) * (ofs & FRACTION_MASK)) >> FRACTION_BITS);
118
119
120
121
122
ofs += incr;
}
}
vp->sample_offset=ofs; /* Update offset */
123
return song->resample_buffer;
124
125
}
126
static sample_t *rs_bidir(MidiSong *song, Voice *vp, Sint32 count)
127
{
128
129
sample_t v1, v2;
Sint32
130
131
132
133
134
ofs=vp->sample_offset,
incr=vp->sample_increment,
le=vp->sample->loop_end,
ls=vp->sample->loop_start;
sample_t
135
*dest=song->resample_buffer,
136
*src=vp->sample->data;
137
Sint32
138
le2 = le<<1,
139
ls2 = ls<<1,
140
i, j;
141
142
/* Play normally until inside the loop region */
143
if (incr > 0 && ofs < ls)
144
145
146
147
{
/* NOTE: Assumes that incr > 0, which is NOT always the case
when doing bidirectional looping. I have yet to see a case
where both ofs <= ls AND incr < 0, however. */
148
i = PRECALC_LOOP_COUNT(ofs, ls, incr);
149
150
151
152
153
154
if (i > count)
{
i = count;
count = 0;
}
else count -= i;
155
for (j = 0; j < i; j++)
156
{
157
158
159
v1 = src[ofs >> FRACTION_BITS];
v2 = src[(ofs >> FRACTION_BITS)+1];
*dest++ = v1 + (((v2 - v1) * (ofs & FRACTION_MASK)) >> FRACTION_BITS);
160
161
162
163
164
165
166
167
168
ofs += incr;
}
}
/* Then do the bidirectional looping */
while(count)
{
/* Precalc how many times we should go through the loop */
169
i = PRECALC_LOOP_COUNT(ofs, incr > 0 ? le : ls, incr);
170
171
172
173
174
175
if (i > count)
{
i = count;
count = 0;
}
else count -= i;
176
for (j = 0; j < i; j++)
177
{
178
179
180
v1 = src[ofs >> FRACTION_BITS];
v2 = src[(ofs >> FRACTION_BITS)+1];
*dest++ = v1 + (((v2 - v1) * (ofs & FRACTION_MASK)) >> FRACTION_BITS);
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
ofs += incr;
}
if (ofs>=le)
{
/* fold the overshoot back in */
ofs = le2 - ofs;
incr *= -1;
}
else if (ofs <= ls)
{
ofs = ls2 - ofs;
incr *= -1;
}
}
vp->sample_increment=incr;
vp->sample_offset=ofs; /* Update offset */
198
return song->resample_buffer;
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
}
/*********************** vibrato versions ***************************/
/* We only need to compute one half of the vibrato sine cycle */
static int vib_phase_to_inc_ptr(int phase)
{
if (phase < VIBRATO_SAMPLE_INCREMENTS/2)
return VIBRATO_SAMPLE_INCREMENTS/2-1-phase;
else if (phase >= 3*VIBRATO_SAMPLE_INCREMENTS/2)
return 5*VIBRATO_SAMPLE_INCREMENTS/2-1-phase;
else
return phase-VIBRATO_SAMPLE_INCREMENTS/2;
}
214
static Sint32 update_vibrato(MidiSong *song, Voice *vp, int sign)
215
{
216
Sint32 depth;
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
int phase, pb;
double a;
if (vp->vibrato_phase++ >= 2*VIBRATO_SAMPLE_INCREMENTS-1)
vp->vibrato_phase=0;
phase=vib_phase_to_inc_ptr(vp->vibrato_phase);
if (vp->vibrato_sample_increment[phase])
{
if (sign)
return -vp->vibrato_sample_increment[phase];
else
return vp->vibrato_sample_increment[phase];
}
/* Need to compute this sample increment. */
depth=vp->sample->vibrato_depth<<7;
if (vp->vibrato_sweep)
{
/* Need to update sweep */
vp->vibrato_sweep_position += vp->vibrato_sweep;
if (vp->vibrato_sweep_position >= (1<<SWEEP_SHIFT))
vp->vibrato_sweep=0;
else
{
/* Adjust depth */
depth *= vp->vibrato_sweep_position;
depth >>= SWEEP_SHIFT;
}
}
a = FSCALE(((double)(vp->sample->sample_rate) *
(double)(vp->frequency)) /
((double)(vp->sample->root_freq) *
253
(double)(song->rate)),
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
FRACTION_BITS);
pb=(int)((sine(vp->vibrato_phase *
(SINE_CYCLE_LENGTH/(2*VIBRATO_SAMPLE_INCREMENTS)))
* (double)(depth) * VIBRATO_AMPLITUDE_TUNING));
if (pb<0)
{
pb=-pb;
a /= bend_fine[(pb>>5) & 0xFF] * bend_coarse[pb>>13];
}
else
a *= bend_fine[(pb>>5) & 0xFF] * bend_coarse[pb>>13];
/* If the sweep's over, we can store the newly computed sample_increment */
if (!vp->vibrato_sweep)
270
vp->vibrato_sample_increment[phase]=(Sint32) a;
271
272
273
274
if (sign)
a = -a; /* need to preserve the loop direction */
275
return (Sint32) a;
276
277
}
278
static sample_t *rs_vib_plain(MidiSong *song, int v, Sint32 *countptr)
279
280
281
282
{
/* Play sample until end, then free the voice. */
283
284
sample_t v1, v2;
Voice *vp=&(song->voice[v]);
285
sample_t
286
*dest=song->resample_buffer,
287
*src=vp->sample->data;
288
Sint32
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
le=vp->sample->data_length,
ofs=vp->sample_offset,
incr=vp->sample_increment,
count=*countptr;
int
cc=vp->vibrato_control_counter;
/* This has never been tested */
if (incr<0) incr = -incr; /* In case we're coming out of a bidir loop */
while (count--)
{
if (!cc--)
{
cc=vp->vibrato_control_ratio;
305
incr=update_vibrato(song, vp, 0);
306
}
307
308
309
v1 = src[ofs >> FRACTION_BITS];
v2 = src[(ofs >> FRACTION_BITS)+1];
*dest++ = v1 + (((v2 - v1) * (ofs & FRACTION_MASK)) >> FRACTION_BITS);
310
311
312
ofs += incr;
if (ofs >= le)
{
313
if (ofs == le)
314
*dest++ = src[(ofs>>FRACTION_BITS)-1]/2;
315
316
317
318
319
320
321
322
323
vp->status=VOICE_FREE;
*countptr-=count+1;
break;
}
}
vp->vibrato_control_counter=cc;
vp->sample_increment=incr;
vp->sample_offset=ofs; /* Update offset */
324
return song->resample_buffer;
325
326
}
327
static sample_t *rs_vib_loop(MidiSong *song, Voice *vp, Sint32 count)
328
329
330
331
{
/* Play sample until end-of-loop, skip back and continue. */
332
333
sample_t v1, v2;
Sint32
334
335
336
337
338
ofs=vp->sample_offset,
incr=vp->sample_increment,
le=vp->sample->loop_end,
ll=le - vp->sample->loop_start;
sample_t
339
*dest=song->resample_buffer,
340
341
342
*src=vp->sample->data;
int
cc=vp->vibrato_control_counter;
343
Sint32 i, j;
344
345
346
347
348
349
int
vibflag=0;
while (count)
{
/* Hopefully the loop is longer than an increment */
350
while(ofs >= le)
351
352
353
ofs -= ll;
/* Precalc how many times to go through the loop, taking
the vibrato control ratio into account this time. */
354
i = PRECALC_LOOP_COUNT(ofs, le, incr);
355
356
357
358
359
360
361
362
if(i > count) i = count;
if(i > cc)
{
i = cc;
vibflag = 1;
}
else cc -= i;
count -= i;
363
for (j = 0; j < i; j++)
364
{
365
366
367
v1 = src[ofs >> FRACTION_BITS];
v2 = src[(ofs >> FRACTION_BITS)+1];
*dest++ = v1 + (((v2 - v1) * (ofs & FRACTION_MASK)) >> FRACTION_BITS);
368
369
370
371
372
ofs += incr;
}
if(vibflag)
{
cc = vp->vibrato_control_ratio;
373
incr = update_vibrato(song, vp, 0);
374
375
376
377
378
379
380
vibflag = 0;
}
}
vp->vibrato_control_counter=cc;
vp->sample_increment=incr;
vp->sample_offset=ofs; /* Update offset */
381
return song->resample_buffer;
382
383
}
384
static sample_t *rs_vib_bidir(MidiSong *song, Voice *vp, Sint32 count)
385
{
386
387
sample_t v1, v2;
Sint32
388
389
390
391
392
ofs=vp->sample_offset,
incr=vp->sample_increment,
le=vp->sample->loop_end,
ls=vp->sample->loop_start;
sample_t
393
*dest=song->resample_buffer,
394
395
396
*src=vp->sample->data;
int
cc=vp->vibrato_control_counter;
397
Sint32
398
399
le2=le<<1,
ls2=ls<<1,
400
i, j;
401
402
403
404
int
vibflag = 0;
/* Play normally until inside the loop region */
405
while (count && incr > 0 && ofs < ls)
406
{
407
i = PRECALC_LOOP_COUNT(ofs, ls, incr);
408
409
410
411
412
413
414
415
if (i > count) i = count;
if (i > cc)
{
i = cc;
vibflag = 1;
}
else cc -= i;
count -= i;
416
for (j = 0; j < i; j++)
417
{
418
419
420
v1 = src[ofs >> FRACTION_BITS];
v2 = src[(ofs >> FRACTION_BITS)+1];
*dest++ = v1 + (((v2 - v1) * (ofs & FRACTION_MASK)) >> FRACTION_BITS);
421
422
423
424
425
ofs += incr;
}
if (vibflag)
{
cc = vp->vibrato_control_ratio;
426
incr = update_vibrato(song, vp, 0);
427
428
429
430
431
432
433
434
435
vibflag = 0;
}
}
/* Then do the bidirectional looping */
while (count)
{
/* Precalc how many times we should go through the loop */
436
i = PRECALC_LOOP_COUNT(ofs, incr > 0 ? le : ls, incr);
437
438
439
440
441
442
443
444
445
446
if(i > count) i = count;
if(i > cc)
{
i = cc;
vibflag = 1;
}
else cc -= i;
count -= i;
while (i--)
{
447
448
449
v1 = src[ofs >> FRACTION_BITS];
v2 = src[(ofs >> FRACTION_BITS)+1];
*dest++ = v1 + (((v2 - v1) * (ofs & FRACTION_MASK)) >> FRACTION_BITS);
450
451
452
453
454
ofs += incr;
}
if (vibflag)
{
cc = vp->vibrato_control_ratio;
455
incr = update_vibrato(song, vp, (incr < 0));
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
vibflag = 0;
}
if (ofs >= le)
{
/* fold the overshoot back in */
ofs = le2 - ofs;
incr *= -1;
}
else if (ofs <= ls)
{
ofs = ls2 - ofs;
incr *= -1;
}
}
vp->vibrato_control_counter=cc;
vp->sample_increment=incr;
vp->sample_offset=ofs; /* Update offset */
474
return song->resample_buffer;
475
476
}
477
sample_t *resample_voice(MidiSong *song, int v, Sint32 *countptr)
478
{
479
480
481
Sint32 ofs;
Uint8 modes;
Voice *vp=&(song->voice[v]);
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
if (!(vp->sample->sample_rate))
{
/* Pre-resampled data -- just update the offset and check if
we're out of data. */
ofs=vp->sample_offset >> FRACTION_BITS; /* Kind of silly to use
FRACTION_BITS here... */
if (*countptr >= (vp->sample->data_length>>FRACTION_BITS) - ofs)
{
/* Note finished. Free the voice. */
vp->status = VOICE_FREE;
/* Let the caller know how much data we had left */
*countptr = (vp->sample->data_length>>FRACTION_BITS) - ofs;
}
else
vp->sample_offset += *countptr << FRACTION_BITS;
500
return vp->sample->data+ofs;
501
502
503
504
505
506
507
508
509
510
511
512
}
/* Need to resample. Use the proper function. */
modes=vp->sample->modes;
if (vp->vibrato_control_ratio)
{
if ((modes & MODES_LOOPING) &&
((modes & MODES_ENVELOPE) ||
(vp->status==VOICE_ON || vp->status==VOICE_SUSTAINED)))
{
if (modes & MODES_PINGPONG)
513
return rs_vib_bidir(song, vp, *countptr);
514
else
515
return rs_vib_loop(song, vp, *countptr);
516
517
}
else
518
return rs_vib_plain(song, v, countptr);
519
520
521
522
523
524
525
526
}
else
{
if ((modes & MODES_LOOPING) &&
((modes & MODES_ENVELOPE) ||
(vp->status==VOICE_ON || vp->status==VOICE_SUSTAINED)))
{
if (modes & MODES_PINGPONG)
527
return rs_bidir(song, vp, *countptr);
528
else
529
return rs_loop(song, vp, *countptr);
530
531
}
else
532
return rs_plain(song, v, countptr);
533
534
535
}
}
536
void pre_resample(MidiSong *song, Sample *sp)
537
538
{
double a, xdiff;
539
Sint32 incr, ofs, newlen, count;
540
541
Sint16 *newdata, *dest, *src = (Sint16 *) sp->data, *vptr;
Sint32 v, v1, v2, v3, v4, v5, i;
542
#ifdef DEBUG_CHATTER
543
544
545
546
547
static const char note_name[12][3] =
{
"C", "C#", "D", "D#", "E", "F", "F#", "G", "G#", "A", "A#", "B"
};
548
549
550
551
SNDDBG((" * pre-resampling for note %d (%s%d)\n",
sp->note_to_use,
note_name[sp->note_to_use % 12], (sp->note_to_use & 0x7F) / 12));
#endif
552
553
554
555
556
557
558
a = ((double) (sp->root_freq) * song->rate) /
((double) (sp->sample_rate) * freq_table[(int) (sp->note_to_use)]);
if(sp->data_length * a >= 0x7fffffffL) { /* Too large to compute */
SNDDBG((" *** Can't pre-resampling for note %d\n", sp->note_to_use));
return;
}
559
560
newlen = (Sint32)(sp->data_length * a);
561
562
563
count = (newlen >> FRACTION_BITS) - 1;
ofs = incr = (sp->data_length - (1 << FRACTION_BITS)) / count;
564
565
566
567
568
569
570
571
572
if((double)newlen + incr >= 0x7fffffffL) { /* Too large to compute */
SNDDBG((" *** Can't pre-resampling for note %d\n", sp->note_to_use));
return;
}
dest = newdata = (Sint16 *) safe_malloc((newlen >> (FRACTION_BITS - 1)) + 2);
if (!dest)
return;
573
574
575
576
577
if (--count)
*dest++ = src[0];
/* Since we're pre-processing and this doesn't have to be done in
real-time, we go ahead and do the full sliding cubic interpolation. */
578
579
count--;
for(i = 0; i < count; i++)
580
581
{
vptr = src + (ofs >> FRACTION_BITS);
582
v1 = ((vptr>=src+1)? *(vptr - 1):0);
583
584
585
v2 = *vptr;
v3 = *(vptr + 1);
v4 = *(vptr + 2);
586
v5 = v2 - v3;
587
xdiff = FSCALENEG(ofs & FRACTION_MASK, FRACTION_BITS);
588
589
590
v = (Sint32)(v2 + xdiff * (1.0/6.0) * (3 * (v3 - v5) - 2 * v1 - v4 +
xdiff * (3 * (v1 - v2 - v5) + xdiff * (3 * v5 + v4 - v1))));
*dest++ = (Sint16)((v > 32767) ? 32767 : ((v < -32768) ? -32768 : v));
591
592
593
594
595
596
597
ofs += incr;
}
if (ofs & FRACTION_MASK)
{
v1 = src[ofs >> FRACTION_BITS];
v2 = src[(ofs >> FRACTION_BITS) + 1];
598
*dest++ = (Sint16)(v1 + (((v2 - v1) * (ofs & FRACTION_MASK)) >> FRACTION_BITS));
599
600
601
602
}
else
*dest++ = src[ofs >> FRACTION_BITS];
603
604
605
606
*dest = *(dest - 1) / 2;
++dest;
*dest = *(dest - 1) / 2;
607
sp->data_length = newlen;
608
609
sp->loop_start = (Sint32)(sp->loop_start * a);
sp->loop_end = (Sint32)(sp->loop_end * a);
610
611
612
613
free(sp->data);
sp->data = (sample_t *) newdata;
sp->sample_rate = 0;
}