src/gb/audio.c (view raw)
1/* Copyright (c) 2013-2016 Jeffrey Pfau
2 *
3 * This Source Code Form is subject to the terms of the Mozilla Public
4 * License, v. 2.0. If a copy of the MPL was not distributed with this
5 * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
6#include <mgba/internal/gb/audio.h>
7
8#include <mgba/core/blip_buf.h>
9#include <mgba/core/interface.h>
10#include <mgba/core/sync.h>
11#include <mgba/internal/gb/gb.h>
12#include <mgba/internal/gb/serialize.h>
13#include <mgba/internal/gb/io.h>
14
15#ifdef _3DS
16#define blip_add_delta blip_add_delta_fast
17#endif
18
19#define FRAME_CYCLES (DMG_LR35902_FREQUENCY >> 9)
20
21const uint32_t DMG_LR35902_FREQUENCY = 0x400000;
22static const int CLOCKS_PER_BLIP_FRAME = 0x1000;
23static const unsigned BLIP_BUFFER_SIZE = 0x4000;
24const int GB_AUDIO_VOLUME_MAX = 0x100;
25
26static bool _writeSweep(struct GBAudioSweep* sweep, uint8_t value);
27static void _writeDuty(struct GBAudioEnvelope* envelope, uint8_t value);
28static bool _writeEnvelope(struct GBAudioEnvelope* envelope, uint8_t value, enum GBAudioStyle style);
29
30static void _resetSweep(struct GBAudioSweep* sweep);
31static bool _resetEnvelope(struct GBAudioEnvelope* sweep);
32
33static void _updateEnvelope(struct GBAudioEnvelope* envelope);
34static void _updateEnvelopeDead(struct GBAudioEnvelope* envelope);
35static bool _updateSweep(struct GBAudioSquareChannel* sweep, bool initial);
36
37static void _updateSquareSample(struct GBAudioSquareChannel* ch);
38static int32_t _updateSquareChannel(struct GBAudioSquareChannel* ch);
39
40static void _updateFrame(struct mTiming* timing, void* user, uint32_t cyclesLate);
41static void _updateChannel1(struct mTiming* timing, void* user, uint32_t cyclesLate);
42static void _updateChannel2(struct mTiming* timing, void* user, uint32_t cyclesLate);
43static void _updateChannel3(struct mTiming* timing, void* user, uint32_t cyclesLate);
44static void _fadeChannel3(struct mTiming* timing, void* user, uint32_t cyclesLate);
45static void _updateChannel4(struct mTiming* timing, void* user, uint32_t cyclesLate);
46static void _sample(struct mTiming* timing, void* user, uint32_t cyclesLate);
47
48void GBAudioInit(struct GBAudio* audio, size_t samples, uint8_t* nr52, enum GBAudioStyle style) {
49 audio->samples = samples;
50 audio->left = blip_new(BLIP_BUFFER_SIZE);
51 audio->right = blip_new(BLIP_BUFFER_SIZE);
52 audio->clockRate = DMG_LR35902_FREQUENCY;
53 // Guess too large; we hang producing extra samples if we guess too low
54 blip_set_rates(audio->left, DMG_LR35902_FREQUENCY, 96000);
55 blip_set_rates(audio->right, DMG_LR35902_FREQUENCY, 96000);
56 audio->forceDisableCh[0] = false;
57 audio->forceDisableCh[1] = false;
58 audio->forceDisableCh[2] = false;
59 audio->forceDisableCh[3] = false;
60 audio->masterVolume = GB_AUDIO_VOLUME_MAX;
61 audio->nr52 = nr52;
62 audio->style = style;
63 if (style == GB_AUDIO_GBA) {
64 audio->timingFactor = 4;
65 } else {
66 audio->timingFactor = 1;
67 }
68
69 audio->frameEvent.context = audio;
70 audio->frameEvent.name = "GB Audio Frame Sequencer";
71 audio->frameEvent.callback = _updateFrame;
72 audio->frameEvent.priority = 0x10;
73 audio->ch1Event.context = audio;
74 audio->ch1Event.name = "GB Audio Channel 1";
75 audio->ch1Event.callback = _updateChannel1;
76 audio->ch1Event.priority = 0x11;
77 audio->ch2Event.context = audio;
78 audio->ch2Event.name = "GB Audio Channel 2";
79 audio->ch2Event.callback = _updateChannel2;
80 audio->ch2Event.priority = 0x12;
81 audio->ch3Event.context = audio;
82 audio->ch3Event.name = "GB Audio Channel 3";
83 audio->ch3Event.callback = _updateChannel3;
84 audio->ch3Event.priority = 0x13;
85 audio->ch3Fade.context = audio;
86 audio->ch3Fade.name = "GB Audio Channel 3 Memory";
87 audio->ch3Fade.callback = _fadeChannel3;
88 audio->ch3Fade.priority = 0x14;
89 audio->ch4Event.context = audio;
90 audio->ch4Event.name = "GB Audio Channel 4";
91 audio->ch4Event.callback = _updateChannel4;
92 audio->ch4Event.priority = 0x15;
93 audio->sampleEvent.context = audio;
94 audio->sampleEvent.name = "GB Audio Sample";
95 audio->sampleEvent.callback = _sample;
96 audio->ch1Event.priority = 0x18;
97}
98
99void GBAudioDeinit(struct GBAudio* audio) {
100 blip_delete(audio->left);
101 blip_delete(audio->right);
102}
103
104void GBAudioReset(struct GBAudio* audio) {
105 mTimingDeschedule(audio->timing, &audio->frameEvent);
106 mTimingDeschedule(audio->timing, &audio->ch1Event);
107 mTimingDeschedule(audio->timing, &audio->ch2Event);
108 mTimingDeschedule(audio->timing, &audio->ch3Event);
109 mTimingDeschedule(audio->timing, &audio->ch3Fade);
110 mTimingDeschedule(audio->timing, &audio->ch4Event);
111 mTimingDeschedule(audio->timing, &audio->sampleEvent);
112 if (audio->style != GB_AUDIO_GBA) {
113 mTimingSchedule(audio->timing, &audio->sampleEvent, 0);
114 }
115 if (audio->style == GB_AUDIO_GBA) {
116 mTimingSchedule(audio->timing, &audio->frameEvent, 0);
117 }
118 audio->ch1 = (struct GBAudioSquareChannel) { .envelope = { .dead = 2 } };
119 audio->ch2 = (struct GBAudioSquareChannel) { .envelope = { .dead = 2 } };
120 audio->ch3 = (struct GBAudioWaveChannel) { .bank = 0 };
121 // TODO: DMG randomness
122 audio->ch3.wavedata8[0] = 0x00;
123 audio->ch3.wavedata8[1] = 0xFF;
124 audio->ch3.wavedata8[2] = 0x00;
125 audio->ch3.wavedata8[3] = 0xFF;
126 audio->ch3.wavedata8[4] = 0x00;
127 audio->ch3.wavedata8[5] = 0xFF;
128 audio->ch3.wavedata8[6] = 0x00;
129 audio->ch3.wavedata8[7] = 0xFF;
130 audio->ch3.wavedata8[8] = 0x00;
131 audio->ch3.wavedata8[9] = 0xFF;
132 audio->ch3.wavedata8[10] = 0x00;
133 audio->ch3.wavedata8[11] = 0xFF;
134 audio->ch3.wavedata8[12] = 0x00;
135 audio->ch3.wavedata8[13] = 0xFF;
136 audio->ch3.wavedata8[14] = 0x00;
137 audio->ch3.wavedata8[15] = 0xFF;
138 audio->ch4 = (struct GBAudioNoiseChannel) { .envelope = { .dead = 2 } };
139 audio->frame = 0;
140 audio->sampleInterval = 128;
141 audio->lastLeft = 0;
142 audio->lastRight = 0;
143 audio->capLeft = 0;
144 audio->capRight = 0;
145 audio->clock = 0;
146 audio->volumeRight = 0;
147 audio->volumeLeft = 0;
148 audio->ch1Right = false;
149 audio->ch2Right = false;
150 audio->ch3Right = false;
151 audio->ch4Right = false;
152 audio->ch1Left = false;
153 audio->ch2Left = false;
154 audio->ch3Left = false;
155 audio->ch4Left = false;
156 audio->playingCh1 = false;
157 audio->playingCh2 = false;
158 audio->playingCh3 = false;
159 audio->playingCh4 = false;
160 if (audio->p && (audio->p->model == GB_MODEL_DMG || audio->p->model == GB_MODEL_CGB)) {
161 audio->playingCh1 = true;
162 *audio->nr52 |= 0x01;
163 }
164}
165
166void GBAudioResizeBuffer(struct GBAudio* audio, size_t samples) {
167 mCoreSyncLockAudio(audio->p->sync);
168 audio->samples = samples;
169 blip_clear(audio->left);
170 blip_clear(audio->right);
171 audio->clock = 0;
172 mCoreSyncConsumeAudio(audio->p->sync);
173}
174
175void GBAudioWriteNR10(struct GBAudio* audio, uint8_t value) {
176 if (!_writeSweep(&audio->ch1.sweep, value)) {
177 mTimingDeschedule(audio->timing, &audio->ch1Event);
178 audio->playingCh1 = false;
179 *audio->nr52 &= ~0x0001;
180 }
181}
182
183void GBAudioWriteNR11(struct GBAudio* audio, uint8_t value) {
184 _writeDuty(&audio->ch1.envelope, value);
185 audio->ch1.control.length = 64 - audio->ch1.envelope.length;
186}
187
188void GBAudioWriteNR12(struct GBAudio* audio, uint8_t value) {
189 if (!_writeEnvelope(&audio->ch1.envelope, value, audio->style)) {
190 mTimingDeschedule(audio->timing, &audio->ch1Event);
191 audio->playingCh1 = false;
192 *audio->nr52 &= ~0x0001;
193 }
194}
195
196void GBAudioWriteNR13(struct GBAudio* audio, uint8_t value) {
197 audio->ch1.control.frequency &= 0x700;
198 audio->ch1.control.frequency |= GBAudioRegisterControlGetFrequency(value);
199}
200
201void GBAudioWriteNR14(struct GBAudio* audio, uint8_t value) {
202 audio->ch1.control.frequency &= 0xFF;
203 audio->ch1.control.frequency |= GBAudioRegisterControlGetFrequency(value << 8);
204 bool wasStop = audio->ch1.control.stop;
205 audio->ch1.control.stop = GBAudioRegisterControlGetStop(value << 8);
206 if (!wasStop && audio->ch1.control.stop && audio->ch1.control.length && !(audio->frame & 1)) {
207 --audio->ch1.control.length;
208 if (audio->ch1.control.length == 0) {
209 mTimingDeschedule(audio->timing, &audio->ch1Event);
210 audio->playingCh1 = false;
211 }
212 }
213 if (GBAudioRegisterControlIsRestart(value << 8)) {
214 audio->playingCh1 = _resetEnvelope(&audio->ch1.envelope);
215
216 if (audio->playingCh1) {
217 _updateSquareSample(&audio->ch1);
218 }
219
220 audio->ch1.sweep.realFrequency = audio->ch1.control.frequency;
221 _resetSweep(&audio->ch1.sweep);
222 if (audio->playingCh1 && audio->ch1.sweep.shift) {
223 audio->playingCh1 = _updateSweep(&audio->ch1, true);
224 }
225 if (!audio->ch1.control.length) {
226 audio->ch1.control.length = 64;
227 if (audio->ch1.control.stop && !(audio->frame & 1)) {
228 --audio->ch1.control.length;
229 }
230 }
231 if (audio->playingCh1 && audio->ch1.envelope.dead != 2 && !mTimingIsScheduled(audio->timing, &audio->ch1Event)) {
232 mTimingSchedule(audio->timing, &audio->ch1Event, 0);
233 }
234 }
235 *audio->nr52 &= ~0x0001;
236 *audio->nr52 |= audio->playingCh1;
237}
238
239void GBAudioWriteNR21(struct GBAudio* audio, uint8_t value) {
240 _writeDuty(&audio->ch2.envelope, value);
241 audio->ch2.control.length = 64 - audio->ch2.envelope.length;
242}
243
244void GBAudioWriteNR22(struct GBAudio* audio, uint8_t value) {
245 if (!_writeEnvelope(&audio->ch2.envelope, value, audio->style)) {
246 mTimingDeschedule(audio->timing, &audio->ch2Event);
247 audio->playingCh2 = false;
248 *audio->nr52 &= ~0x0002;
249 }
250}
251
252void GBAudioWriteNR23(struct GBAudio* audio, uint8_t value) {
253 audio->ch2.control.frequency &= 0x700;
254 audio->ch2.control.frequency |= GBAudioRegisterControlGetFrequency(value);
255}
256
257void GBAudioWriteNR24(struct GBAudio* audio, uint8_t value) {
258 audio->ch2.control.frequency &= 0xFF;
259 audio->ch2.control.frequency |= GBAudioRegisterControlGetFrequency(value << 8);
260 bool wasStop = audio->ch2.control.stop;
261 audio->ch2.control.stop = GBAudioRegisterControlGetStop(value << 8);
262 if (!wasStop && audio->ch2.control.stop && audio->ch2.control.length && !(audio->frame & 1)) {
263 --audio->ch2.control.length;
264 if (audio->ch2.control.length == 0) {
265 mTimingDeschedule(audio->timing, &audio->ch2Event);
266 audio->playingCh2 = false;
267 }
268 }
269 if (GBAudioRegisterControlIsRestart(value << 8)) {
270 audio->playingCh2 = _resetEnvelope(&audio->ch2.envelope);
271
272 if (audio->playingCh2) {
273 _updateSquareSample(&audio->ch2);
274 }
275
276 if (!audio->ch2.control.length) {
277 audio->ch2.control.length = 64;
278 if (audio->ch2.control.stop && !(audio->frame & 1)) {
279 --audio->ch2.control.length;
280 }
281 }
282 if (audio->playingCh2 && audio->ch2.envelope.dead != 2 && !mTimingIsScheduled(audio->timing, &audio->ch2Event)) {
283 mTimingSchedule(audio->timing, &audio->ch2Event, 0);
284 }
285 }
286 *audio->nr52 &= ~0x0002;
287 *audio->nr52 |= audio->playingCh2 << 1;
288}
289
290void GBAudioWriteNR30(struct GBAudio* audio, uint8_t value) {
291 audio->ch3.enable = GBAudioRegisterBankGetEnable(value);
292 if (!audio->ch3.enable) {
293 audio->playingCh3 = false;
294 *audio->nr52 &= ~0x0004;
295 }
296}
297
298void GBAudioWriteNR31(struct GBAudio* audio, uint8_t value) {
299 audio->ch3.length = 256 - value;
300}
301
302void GBAudioWriteNR32(struct GBAudio* audio, uint8_t value) {
303 audio->ch3.volume = GBAudioRegisterBankVolumeGetVolumeGB(value);
304}
305
306void GBAudioWriteNR33(struct GBAudio* audio, uint8_t value) {
307 audio->ch3.rate &= 0x700;
308 audio->ch3.rate |= GBAudioRegisterControlGetRate(value);
309}
310
311void GBAudioWriteNR34(struct GBAudio* audio, uint8_t value) {
312 audio->ch3.rate &= 0xFF;
313 audio->ch3.rate |= GBAudioRegisterControlGetRate(value << 8);
314 bool wasStop = audio->ch3.stop;
315 audio->ch3.stop = GBAudioRegisterControlGetStop(value << 8);
316 if (!wasStop && audio->ch3.stop && audio->ch3.length && !(audio->frame & 1)) {
317 --audio->ch3.length;
318 if (audio->ch3.length == 0) {
319 audio->playingCh3 = false;
320 }
321 }
322 bool wasEnable = audio->playingCh3;
323 if (GBAudioRegisterControlIsRestart(value << 8)) {
324 audio->playingCh3 = audio->ch3.enable;
325 if (!audio->ch3.length) {
326 audio->ch3.length = 256;
327 if (audio->ch3.stop && !(audio->frame & 1)) {
328 --audio->ch3.length;
329 }
330 }
331
332 if (audio->style == GB_AUDIO_DMG && wasEnable && audio->playingCh3 && audio->ch3.readable) {
333 if (audio->ch3.window < 8) {
334 audio->ch3.wavedata8[0] = audio->ch3.wavedata8[audio->ch3.window >> 1];
335 } else {
336 audio->ch3.wavedata8[0] = audio->ch3.wavedata8[((audio->ch3.window >> 1) & ~3)];
337 audio->ch3.wavedata8[1] = audio->ch3.wavedata8[((audio->ch3.window >> 1) & ~3) + 1];
338 audio->ch3.wavedata8[2] = audio->ch3.wavedata8[((audio->ch3.window >> 1) & ~3) + 2];
339 audio->ch3.wavedata8[3] = audio->ch3.wavedata8[((audio->ch3.window >> 1) & ~3) + 3];
340 }
341 }
342 audio->ch3.window = 0;
343 }
344 mTimingDeschedule(audio->timing, &audio->ch3Fade);
345 mTimingDeschedule(audio->timing, &audio->ch3Event);
346 if (audio->playingCh3) {
347 audio->ch3.readable = audio->style != GB_AUDIO_DMG;
348 // TODO: Where does this cycle delay come from?
349 mTimingSchedule(audio->timing, &audio->ch3Event, audio->timingFactor * 4 + 2 * (2048 - audio->ch3.rate));
350 }
351 *audio->nr52 &= ~0x0004;
352 *audio->nr52 |= audio->playingCh3 << 2;
353}
354
355void GBAudioWriteNR41(struct GBAudio* audio, uint8_t value) {
356 _writeDuty(&audio->ch4.envelope, value);
357 audio->ch4.length = 64 - audio->ch4.envelope.length;
358}
359
360void GBAudioWriteNR42(struct GBAudio* audio, uint8_t value) {
361 if (!_writeEnvelope(&audio->ch4.envelope, value, audio->style)) {
362 mTimingDeschedule(audio->timing, &audio->ch4Event);
363 audio->playingCh4 = false;
364 *audio->nr52 &= ~0x0008;
365 }
366}
367
368void GBAudioWriteNR43(struct GBAudio* audio, uint8_t value) {
369 audio->ch4.ratio = GBAudioRegisterNoiseFeedbackGetRatio(value);
370 audio->ch4.frequency = GBAudioRegisterNoiseFeedbackGetFrequency(value);
371 audio->ch4.power = GBAudioRegisterNoiseFeedbackGetPower(value);
372}
373
374void GBAudioWriteNR44(struct GBAudio* audio, uint8_t value) {
375 bool wasStop = audio->ch4.stop;
376 audio->ch4.stop = GBAudioRegisterNoiseControlGetStop(value);
377 if (!wasStop && audio->ch4.stop && audio->ch4.length && !(audio->frame & 1)) {
378 --audio->ch4.length;
379 if (audio->ch4.length == 0) {
380 mTimingDeschedule(audio->timing, &audio->ch4Event);
381 audio->playingCh4 = false;
382 }
383 }
384 if (GBAudioRegisterNoiseControlIsRestart(value)) {
385 audio->playingCh4 = _resetEnvelope(&audio->ch4.envelope);
386
387 if (audio->ch4.power) {
388 audio->ch4.lfsr = 0x40;
389 } else {
390 audio->ch4.lfsr = 0x4000;
391 }
392 if (!audio->ch4.length) {
393 audio->ch4.length = 64;
394 if (audio->ch4.stop && !(audio->frame & 1)) {
395 --audio->ch4.length;
396 }
397 }
398 if (audio->playingCh4 && audio->ch4.envelope.dead != 2 && !mTimingIsScheduled(audio->timing, &audio->ch4Event)) {
399 mTimingSchedule(audio->timing, &audio->ch4Event, 0);
400 }
401 }
402 *audio->nr52 &= ~0x0008;
403 *audio->nr52 |= audio->playingCh4 << 3;
404}
405
406void GBAudioWriteNR50(struct GBAudio* audio, uint8_t value) {
407 audio->volumeRight = GBRegisterNR50GetVolumeRight(value);
408 audio->volumeLeft = GBRegisterNR50GetVolumeLeft(value);
409}
410
411void GBAudioWriteNR51(struct GBAudio* audio, uint8_t value) {
412 audio->ch1Right = GBRegisterNR51GetCh1Right(value);
413 audio->ch2Right = GBRegisterNR51GetCh2Right(value);
414 audio->ch3Right = GBRegisterNR51GetCh3Right(value);
415 audio->ch4Right = GBRegisterNR51GetCh4Right(value);
416 audio->ch1Left = GBRegisterNR51GetCh1Left(value);
417 audio->ch2Left = GBRegisterNR51GetCh2Left(value);
418 audio->ch3Left = GBRegisterNR51GetCh3Left(value);
419 audio->ch4Left = GBRegisterNR51GetCh4Left(value);
420}
421
422void GBAudioWriteNR52(struct GBAudio* audio, uint8_t value) {
423 bool wasEnable = audio->enable;
424 audio->enable = GBAudioEnableGetEnable(value);
425 if (!audio->enable) {
426 audio->playingCh1 = 0;
427 audio->playingCh2 = 0;
428 audio->playingCh3 = 0;
429 audio->playingCh4 = 0;
430 GBAudioWriteNR10(audio, 0);
431 GBAudioWriteNR12(audio, 0);
432 GBAudioWriteNR13(audio, 0);
433 GBAudioWriteNR14(audio, 0);
434 GBAudioWriteNR22(audio, 0);
435 GBAudioWriteNR23(audio, 0);
436 GBAudioWriteNR24(audio, 0);
437 GBAudioWriteNR30(audio, 0);
438 GBAudioWriteNR32(audio, 0);
439 GBAudioWriteNR33(audio, 0);
440 GBAudioWriteNR34(audio, 0);
441 GBAudioWriteNR42(audio, 0);
442 GBAudioWriteNR43(audio, 0);
443 GBAudioWriteNR44(audio, 0);
444 GBAudioWriteNR50(audio, 0);
445 GBAudioWriteNR51(audio, 0);
446 if (audio->style != GB_AUDIO_DMG) {
447 GBAudioWriteNR11(audio, 0);
448 GBAudioWriteNR21(audio, 0);
449 GBAudioWriteNR31(audio, 0);
450 GBAudioWriteNR41(audio, 0);
451 }
452
453 if (audio->p) {
454 audio->p->memory.io[REG_NR10] = 0;
455 audio->p->memory.io[REG_NR11] = 0;
456 audio->p->memory.io[REG_NR12] = 0;
457 audio->p->memory.io[REG_NR13] = 0;
458 audio->p->memory.io[REG_NR14] = 0;
459 audio->p->memory.io[REG_NR21] = 0;
460 audio->p->memory.io[REG_NR22] = 0;
461 audio->p->memory.io[REG_NR23] = 0;
462 audio->p->memory.io[REG_NR24] = 0;
463 audio->p->memory.io[REG_NR30] = 0;
464 audio->p->memory.io[REG_NR31] = 0;
465 audio->p->memory.io[REG_NR32] = 0;
466 audio->p->memory.io[REG_NR33] = 0;
467 audio->p->memory.io[REG_NR34] = 0;
468 audio->p->memory.io[REG_NR42] = 0;
469 audio->p->memory.io[REG_NR43] = 0;
470 audio->p->memory.io[REG_NR44] = 0;
471 audio->p->memory.io[REG_NR50] = 0;
472 audio->p->memory.io[REG_NR51] = 0;
473 if (audio->style != GB_AUDIO_DMG) {
474 audio->p->memory.io[REG_NR11] = 0;
475 audio->p->memory.io[REG_NR21] = 0;
476 audio->p->memory.io[REG_NR31] = 0;
477 audio->p->memory.io[REG_NR41] = 0;
478 }
479 }
480 *audio->nr52 &= ~0x000F;
481 } else if (!wasEnable) {
482 audio->frame = 7;
483 }
484}
485
486void _updateFrame(struct mTiming* timing, void* user, uint32_t cyclesLate) {
487 struct GBAudio* audio = user;
488 GBAudioUpdateFrame(audio, timing);
489 if (audio->style == GB_AUDIO_GBA) {
490 mTimingSchedule(timing, &audio->frameEvent, audio->timingFactor * FRAME_CYCLES - cyclesLate);
491 }
492}
493
494void GBAudioUpdateFrame(struct GBAudio* audio, struct mTiming* timing) {
495 int frame = (audio->frame + 1) & 7;
496 audio->frame = frame;
497
498 switch (frame) {
499 case 2:
500 case 6:
501 if (audio->ch1.sweep.enable) {
502 --audio->ch1.sweep.step;
503 if (audio->ch1.sweep.step == 0) {
504 audio->playingCh1 = _updateSweep(&audio->ch1, false);
505 *audio->nr52 &= ~0x0001;
506 *audio->nr52 |= audio->playingCh1;
507 }
508 }
509 // Fall through
510 case 0:
511 case 4:
512 if (audio->ch1.control.length && audio->ch1.control.stop) {
513 --audio->ch1.control.length;
514 if (audio->ch1.control.length == 0) {
515 mTimingDeschedule(timing, &audio->ch1Event);
516 audio->playingCh1 = 0;
517 *audio->nr52 &= ~0x0001;
518 }
519 }
520
521 if (audio->ch2.control.length && audio->ch2.control.stop) {
522 --audio->ch2.control.length;
523 if (audio->ch2.control.length == 0) {
524 mTimingDeschedule(timing, &audio->ch2Event);
525 audio->playingCh2 = 0;
526 *audio->nr52 &= ~0x0002;
527 }
528 }
529
530 if (audio->ch3.length && audio->ch3.stop) {
531 --audio->ch3.length;
532 if (audio->ch3.length == 0) {
533 mTimingDeschedule(timing, &audio->ch3Event);
534 audio->playingCh3 = 0;
535 *audio->nr52 &= ~0x0004;
536 }
537 }
538
539 if (audio->ch4.length && audio->ch4.stop) {
540 --audio->ch4.length;
541 if (audio->ch4.length == 0) {
542 mTimingDeschedule(timing, &audio->ch4Event);
543 audio->playingCh4 = 0;
544 *audio->nr52 &= ~0x0008;
545 }
546 }
547 break;
548 case 7:
549 if (audio->playingCh1 && !audio->ch1.envelope.dead) {
550 --audio->ch1.envelope.nextStep;
551 if (audio->ch1.envelope.nextStep == 0) {
552 _updateEnvelope(&audio->ch1.envelope);
553 if (audio->ch1.envelope.dead == 2) {
554 mTimingDeschedule(timing, &audio->ch1Event);
555 }
556 _updateSquareSample(&audio->ch1);
557 }
558 }
559
560 if (audio->playingCh2 && !audio->ch2.envelope.dead) {
561 --audio->ch2.envelope.nextStep;
562 if (audio->ch2.envelope.nextStep == 0) {
563 _updateEnvelope(&audio->ch2.envelope);
564 if (audio->ch2.envelope.dead == 2) {
565 mTimingDeschedule(timing, &audio->ch2Event);
566 }
567 _updateSquareSample(&audio->ch2);
568 }
569 }
570
571 if (audio->playingCh4 && !audio->ch4.envelope.dead) {
572 --audio->ch4.envelope.nextStep;
573 if (audio->ch4.envelope.nextStep == 0) {
574 int8_t sample = (audio->ch4.sample > 0) * 0x8;
575 _updateEnvelope(&audio->ch4.envelope);
576 if (audio->ch4.envelope.dead == 2) {
577 mTimingDeschedule(timing, &audio->ch4Event);
578 }
579 audio->ch4.sample = sample * audio->ch4.envelope.currentVolume;
580 }
581 }
582 break;
583 }
584}
585
586void GBAudioSamplePSG(struct GBAudio* audio, int16_t* left, int16_t* right) {
587 int sampleLeft = 0;
588 int sampleRight = 0;
589
590 if (audio->playingCh1 && !audio->forceDisableCh[0]) {
591 if (audio->ch1Left) {
592 sampleLeft += audio->ch1.sample;
593 }
594
595 if (audio->ch1Right) {
596 sampleRight += audio->ch1.sample;
597 }
598 }
599
600 if (audio->playingCh2 && !audio->forceDisableCh[1]) {
601 if (audio->ch2Left) {
602 sampleLeft += audio->ch2.sample;
603 }
604
605 if (audio->ch2Right) {
606 sampleRight += audio->ch2.sample;
607 }
608 }
609
610 if (audio->playingCh3 && !audio->forceDisableCh[2]) {
611 if (audio->ch3Left) {
612 sampleLeft += audio->ch3.sample;
613 }
614
615 if (audio->ch3Right) {
616 sampleRight += audio->ch3.sample;
617 }
618 }
619
620 if (audio->playingCh4 && !audio->forceDisableCh[3]) {
621 if (audio->ch4Left) {
622 sampleLeft += audio->ch4.sample;
623 }
624
625 if (audio->ch4Right) {
626 sampleRight += audio->ch4.sample;
627 }
628 }
629
630 int dcOffset = audio->style == GB_AUDIO_GBA ? 0 : 0x1FC;
631 *left = (sampleLeft - dcOffset) * (1 + audio->volumeLeft);
632 *right = (sampleRight - dcOffset) * (1 + audio->volumeRight);
633}
634
635static void _sample(struct mTiming* timing, void* user, uint32_t cyclesLate) {
636 struct GBAudio* audio = user;
637 int16_t sampleLeft = 0;
638 int16_t sampleRight = 0;
639 GBAudioSamplePSG(audio, &sampleLeft, &sampleRight);
640 sampleLeft = (sampleLeft * audio->masterVolume) >> 6;
641 sampleRight = (sampleRight * audio->masterVolume) >> 6;
642
643 mCoreSyncLockAudio(audio->p->sync);
644 unsigned produced;
645
646 int16_t degradedLeft = sampleLeft - (audio->capLeft >> 16);
647 int16_t degradedRight = sampleRight - (audio->capRight >> 16);
648 audio->capLeft = (sampleLeft << 16) - degradedLeft * 65184;
649 audio->capRight = (sampleRight << 16) - degradedRight * 65184;
650 sampleLeft = degradedLeft;
651 sampleRight = degradedRight;
652
653 if ((size_t) blip_samples_avail(audio->left) < audio->samples) {
654 blip_add_delta(audio->left, audio->clock, sampleLeft - audio->lastLeft);
655 blip_add_delta(audio->right, audio->clock, sampleRight - audio->lastRight);
656 audio->clock += audio->sampleInterval;
657 if (audio->clock >= CLOCKS_PER_BLIP_FRAME) {
658 blip_end_frame(audio->left, CLOCKS_PER_BLIP_FRAME);
659 blip_end_frame(audio->right, CLOCKS_PER_BLIP_FRAME);
660 audio->clock -= CLOCKS_PER_BLIP_FRAME;
661 }
662 }
663 audio->lastLeft = sampleLeft;
664 audio->lastRight = sampleRight;
665 produced = blip_samples_avail(audio->left);
666 if (audio->p->stream && audio->p->stream->postAudioFrame) {
667 audio->p->stream->postAudioFrame(audio->p->stream, sampleLeft, sampleRight);
668 }
669 bool wait = produced >= audio->samples;
670 mCoreSyncProduceAudio(audio->p->sync, wait);
671
672 if (wait && audio->p->stream && audio->p->stream->postAudioBuffer) {
673 audio->p->stream->postAudioBuffer(audio->p->stream, audio->left, audio->right);
674 }
675 mTimingSchedule(timing, &audio->sampleEvent, audio->sampleInterval * audio->timingFactor - cyclesLate);
676}
677
678bool _resetEnvelope(struct GBAudioEnvelope* envelope) {
679 envelope->currentVolume = envelope->initialVolume;
680 _updateEnvelopeDead(envelope);
681 if (!envelope->dead) {
682 envelope->nextStep = envelope->stepTime;
683 }
684 return envelope->initialVolume || envelope->direction;
685}
686
687void _resetSweep(struct GBAudioSweep* sweep) {
688 sweep->step = sweep->time;
689 sweep->enable = (sweep->step != 8) || sweep->shift;
690 sweep->occurred = false;
691}
692
693bool _writeSweep(struct GBAudioSweep* sweep, uint8_t value) {
694 sweep->shift = GBAudioRegisterSquareSweepGetShift(value);
695 bool oldDirection = sweep->direction;
696 sweep->direction = GBAudioRegisterSquareSweepGetDirection(value);
697 bool on = true;
698 if (sweep->occurred && oldDirection && !sweep->direction) {
699 on = false;
700 }
701 sweep->occurred = false;
702 sweep->time = GBAudioRegisterSquareSweepGetTime(value);
703 if (!sweep->time) {
704 sweep->time = 8;
705 }
706 return on;
707}
708
709void _writeDuty(struct GBAudioEnvelope* envelope, uint8_t value) {
710 envelope->length = GBAudioRegisterDutyGetLength(value);
711 envelope->duty = GBAudioRegisterDutyGetDuty(value);
712}
713
714bool _writeEnvelope(struct GBAudioEnvelope* envelope, uint8_t value, enum GBAudioStyle style) {
715 envelope->stepTime = GBAudioRegisterSweepGetStepTime(value);
716 envelope->direction = GBAudioRegisterSweepGetDirection(value);
717 envelope->initialVolume = GBAudioRegisterSweepGetInitialVolume(value);
718 if (style == GB_AUDIO_DMG && !envelope->stepTime) {
719 // TODO: Improve "zombie" mode
720 ++envelope->currentVolume;
721 envelope->currentVolume &= 0xF;
722 }
723 _updateEnvelopeDead(envelope);
724 return (envelope->initialVolume || envelope->direction) && envelope->dead != 2;
725}
726
727static void _updateSquareSample(struct GBAudioSquareChannel* ch) {
728 ch->sample = ch->control.hi * ch->envelope.currentVolume * 0x8;
729}
730
731static int32_t _updateSquareChannel(struct GBAudioSquareChannel* ch) {
732 ch->control.hi = !ch->control.hi;
733 _updateSquareSample(ch);
734 int period = 4 * (2048 - ch->control.frequency);
735 switch (ch->envelope.duty) {
736 case 0:
737 return ch->control.hi ? period : period * 7;
738 case 1:
739 return ch->control.hi ? period * 2 : period * 6;
740 case 2:
741 return period * 4;
742 case 3:
743 return ch->control.hi ? period * 6 : period * 2;
744 default:
745 // This should never be hit
746 return period * 4;
747 }
748}
749
750static void _updateEnvelope(struct GBAudioEnvelope* envelope) {
751 if (envelope->direction) {
752 ++envelope->currentVolume;
753 } else {
754 --envelope->currentVolume;
755 }
756 if (envelope->currentVolume >= 15) {
757 envelope->currentVolume = 15;
758 envelope->dead = 1;
759 } else if (envelope->currentVolume <= 0) {
760 envelope->currentVolume = 0;
761 envelope->dead = 2;
762 } else {
763 envelope->nextStep = envelope->stepTime;
764 }
765}
766
767static void _updateEnvelopeDead(struct GBAudioEnvelope* envelope) {
768 if (!envelope->stepTime) {
769 envelope->dead = envelope->currentVolume ? 1 : 2;
770 } else if (!envelope->direction && !envelope->currentVolume) {
771 envelope->dead = 2;
772 } else if (envelope->direction && envelope->currentVolume == 0xF) {
773 envelope->dead = 1;
774 } else {
775 envelope->dead = 0;
776 }
777}
778
779static bool _updateSweep(struct GBAudioSquareChannel* ch, bool initial) {
780 if (initial || ch->sweep.time != 8) {
781 int frequency = ch->sweep.realFrequency;
782 if (ch->sweep.direction) {
783 frequency -= frequency >> ch->sweep.shift;
784 if (!initial && frequency >= 0) {
785 ch->control.frequency = frequency;
786 ch->sweep.realFrequency = frequency;
787 }
788 } else {
789 frequency += frequency >> ch->sweep.shift;
790 if (frequency < 2048) {
791 if (!initial && ch->sweep.shift) {
792 ch->control.frequency = frequency;
793 ch->sweep.realFrequency = frequency;
794 if (!_updateSweep(ch, true)) {
795 return false;
796 }
797 }
798 } else {
799 return false;
800 }
801 }
802 ch->sweep.occurred = true;
803 }
804 ch->sweep.step = ch->sweep.time;
805 return true;
806}
807
808static void _updateChannel1(struct mTiming* timing, void* user, uint32_t cyclesLate) {
809 struct GBAudio* audio = user;
810 struct GBAudioSquareChannel* ch = &audio->ch1;
811 int cycles = _updateSquareChannel(ch);
812 mTimingSchedule(timing, &audio->ch1Event, audio->timingFactor * cycles - cyclesLate);
813}
814
815static void _updateChannel2(struct mTiming* timing, void* user, uint32_t cyclesLate) {
816 struct GBAudio* audio = user;
817 struct GBAudioSquareChannel* ch = &audio->ch2;
818 int cycles = _updateSquareChannel(ch);
819 mTimingSchedule(timing, &audio->ch2Event, audio->timingFactor * cycles - cyclesLate);
820}
821
822static void _updateChannel3(struct mTiming* timing, void* user, uint32_t cyclesLate) {
823 struct GBAudio* audio = user;
824 struct GBAudioWaveChannel* ch = &audio->ch3;
825 int i;
826 int volume;
827 switch (ch->volume) {
828 case 0:
829 volume = 0;
830 break;
831 case 1:
832 volume = 4;
833 break;
834 case 2:
835 volume = 2;
836 break;
837 case 3:
838 volume = 1;
839 break;
840 default:
841 volume = 3;
842 break;
843 }
844 int start;
845 int end;
846 switch (audio->style) {
847 case GB_AUDIO_DMG:
848 default:
849 ++ch->window;
850 ch->window &= 0x1F;
851 ch->sample = ch->wavedata8[ch->window >> 1];
852 if (!(ch->window & 1)) {
853 ch->sample >>= 4;
854 }
855 ch->sample &= 0xF;
856 break;
857 case GB_AUDIO_GBA:
858 if (ch->size) {
859 start = 7;
860 end = 0;
861 } else if (ch->bank) {
862 start = 7;
863 end = 4;
864 } else {
865 start = 3;
866 end = 0;
867 }
868 uint32_t bitsCarry = ch->wavedata32[end] & 0x000000F0;
869 uint32_t bits;
870 for (i = start; i >= end; --i) {
871 bits = ch->wavedata32[i] & 0x000000F0;
872 ch->wavedata32[i] = ((ch->wavedata32[i] & 0x0F0F0F0F) << 4) | ((ch->wavedata32[i] & 0xF0F0F000) >> 12);
873 ch->wavedata32[i] |= bitsCarry << 20;
874 bitsCarry = bits;
875 }
876 ch->sample = bitsCarry >> 4;
877 break;
878 }
879 ch->sample *= volume * 2;
880 audio->ch3.readable = true;
881 if (audio->style == GB_AUDIO_DMG) {
882 mTimingDeschedule(audio->timing, &audio->ch3Fade);
883 mTimingSchedule(timing, &audio->ch3Fade, 2 - cyclesLate);
884 }
885 int cycles = 2 * (2048 - ch->rate);
886 mTimingSchedule(timing, &audio->ch3Event, audio->timingFactor * cycles - cyclesLate);
887}
888static void _fadeChannel3(struct mTiming* timing, void* user, uint32_t cyclesLate) {
889 UNUSED(timing);
890 UNUSED(cyclesLate);
891 struct GBAudio* audio = user;
892 audio->ch3.readable = false;
893}
894
895static void _updateChannel4(struct mTiming* timing, void* user, uint32_t cyclesLate) {
896 struct GBAudio* audio = user;
897 struct GBAudioNoiseChannel* ch = &audio->ch4;
898
899 int32_t baseCycles = ch->ratio ? 2 * ch->ratio : 1;
900 baseCycles <<= ch->frequency;
901 baseCycles *= 8 * audio->timingFactor;
902 int32_t cycles = 0;
903
904 do {
905 int lsb = ch->lfsr & 1;
906 ch->sample = lsb * 0x8;
907 ch->sample *= ch->envelope.currentVolume;
908 ch->lfsr >>= 1;
909 ch->lfsr ^= (lsb * 0x60) << (ch->power ? 0 : 8);
910 cycles += baseCycles;
911 } while (cycles + baseCycles < audio->sampleInterval);
912 mTimingSchedule(timing, &audio->ch4Event, cycles - cyclesLate);
913}
914
915void GBAudioPSGSerialize(const struct GBAudio* audio, struct GBSerializedPSGState* state, uint32_t* flagsOut) {
916 uint32_t flags = 0;
917 uint32_t ch1Flags = 0;
918 uint32_t ch2Flags = 0;
919 uint32_t ch4Flags = 0;
920
921 flags = GBSerializedAudioFlagsSetFrame(flags, audio->frame);
922 STORE_32LE(audio->frameEvent.when - mTimingCurrentTime(audio->timing), 0, &state->ch1.nextFrame);
923
924 flags = GBSerializedAudioFlagsSetCh1Volume(flags, audio->ch1.envelope.currentVolume);
925 flags = GBSerializedAudioFlagsSetCh1Dead(flags, audio->ch1.envelope.dead);
926 flags = GBSerializedAudioFlagsSetCh1Hi(flags, audio->ch1.control.hi);
927 flags = GBSerializedAudioFlagsSetCh1SweepEnabled(flags, audio->ch1.sweep.enable);
928 flags = GBSerializedAudioFlagsSetCh1SweepOccurred(flags, audio->ch1.sweep.occurred);
929 ch1Flags = GBSerializedAudioEnvelopeSetLength(ch1Flags, audio->ch1.control.length);
930 ch1Flags = GBSerializedAudioEnvelopeSetNextStep(ch1Flags, audio->ch1.envelope.nextStep);
931 ch1Flags = GBSerializedAudioEnvelopeSetFrequency(ch1Flags, audio->ch1.sweep.realFrequency);
932 STORE_32LE(ch1Flags, 0, &state->ch1.envelope);
933 STORE_32LE(audio->ch1Event.when - mTimingCurrentTime(audio->timing), 0, &state->ch1.nextEvent);
934
935 flags = GBSerializedAudioFlagsSetCh2Volume(flags, audio->ch2.envelope.currentVolume);
936 flags = GBSerializedAudioFlagsSetCh2Dead(flags, audio->ch2.envelope.dead);
937 flags = GBSerializedAudioFlagsSetCh2Hi(flags, audio->ch2.control.hi);
938 ch2Flags = GBSerializedAudioEnvelopeSetLength(ch2Flags, audio->ch2.control.length);
939 ch2Flags = GBSerializedAudioEnvelopeSetNextStep(ch2Flags, audio->ch2.envelope.nextStep);
940 STORE_32LE(ch2Flags, 0, &state->ch2.envelope);
941 STORE_32LE(audio->ch2Event.when - mTimingCurrentTime(audio->timing), 0, &state->ch2.nextEvent);
942
943 flags = GBSerializedAudioFlagsSetCh3Readable(flags, audio->ch3.readable);
944 memcpy(state->ch3.wavebanks, audio->ch3.wavedata32, sizeof(state->ch3.wavebanks));
945 STORE_16LE(audio->ch3.length, 0, &state->ch3.length);
946 STORE_32LE(audio->ch3Event.when - mTimingCurrentTime(audio->timing), 0, &state->ch3.nextEvent);
947 STORE_32LE(audio->ch3Fade.when - mTimingCurrentTime(audio->timing), 0, &state->ch1.nextCh3Fade);
948
949 flags = GBSerializedAudioFlagsSetCh4Volume(flags, audio->ch4.envelope.currentVolume);
950 flags = GBSerializedAudioFlagsSetCh4Dead(flags, audio->ch4.envelope.dead);
951 STORE_32LE(audio->ch4.lfsr, 0, &state->ch4.lfsr);
952 ch4Flags = GBSerializedAudioEnvelopeSetLength(ch4Flags, audio->ch4.length);
953 ch4Flags = GBSerializedAudioEnvelopeSetNextStep(ch4Flags, audio->ch4.envelope.nextStep);
954 STORE_32LE(ch4Flags, 0, &state->ch4.envelope);
955 STORE_32LE(audio->ch4Event.when - mTimingCurrentTime(audio->timing), 0, &state->ch4.nextEvent);
956
957 STORE_32LE(flags, 0, flagsOut);
958}
959
960void GBAudioPSGDeserialize(struct GBAudio* audio, const struct GBSerializedPSGState* state, const uint32_t* flagsIn) {
961 uint32_t flags;
962 uint32_t ch1Flags = 0;
963 uint32_t ch2Flags = 0;
964 uint32_t ch4Flags = 0;
965 uint32_t when;
966
967 audio->playingCh1 = !!(*audio->nr52 & 0x0001);
968 audio->playingCh2 = !!(*audio->nr52 & 0x0002);
969 audio->playingCh3 = !!(*audio->nr52 & 0x0004);
970 audio->playingCh4 = !!(*audio->nr52 & 0x0008);
971 audio->enable = GBAudioEnableGetEnable(*audio->nr52);
972
973 if (audio->style == GB_AUDIO_GBA) {
974 LOAD_32LE(when, 0, &state->ch1.nextFrame);
975 mTimingSchedule(audio->timing, &audio->frameEvent, when);
976 }
977
978 LOAD_32LE(flags, 0, flagsIn);
979 audio->frame = GBSerializedAudioFlagsGetFrame(flags);
980
981 LOAD_32LE(ch1Flags, 0, &state->ch1.envelope);
982 audio->ch1.envelope.currentVolume = GBSerializedAudioFlagsGetCh1Volume(flags);
983 audio->ch1.envelope.dead = GBSerializedAudioFlagsGetCh1Dead(flags);
984 audio->ch1.control.hi = GBSerializedAudioFlagsGetCh1Hi(flags);
985 audio->ch1.sweep.enable = GBSerializedAudioFlagsGetCh1SweepEnabled(flags);
986 audio->ch1.sweep.occurred = GBSerializedAudioFlagsGetCh1SweepOccurred(flags);
987 audio->ch1.control.length = GBSerializedAudioEnvelopeGetLength(ch1Flags);
988 audio->ch1.envelope.nextStep = GBSerializedAudioEnvelopeGetNextStep(ch1Flags);
989 audio->ch1.sweep.realFrequency = GBSerializedAudioEnvelopeGetFrequency(ch1Flags);
990 LOAD_32LE(when, 0, &state->ch1.nextEvent);
991 if (audio->ch1.envelope.dead < 2 && audio->playingCh1) {
992 mTimingSchedule(audio->timing, &audio->ch1Event, when);
993 }
994
995 LOAD_32LE(ch2Flags, 0, &state->ch2.envelope);
996 audio->ch2.envelope.currentVolume = GBSerializedAudioFlagsGetCh2Volume(flags);
997 audio->ch2.envelope.dead = GBSerializedAudioFlagsGetCh2Dead(flags);
998 audio->ch2.control.hi = GBSerializedAudioFlagsGetCh2Hi(flags);
999 audio->ch2.control.length = GBSerializedAudioEnvelopeGetLength(ch2Flags);
1000 audio->ch2.envelope.nextStep = GBSerializedAudioEnvelopeGetNextStep(ch2Flags);
1001 LOAD_32LE(when, 0, &state->ch2.nextEvent);
1002 if (audio->ch2.envelope.dead < 2 && audio->playingCh2) {
1003 mTimingSchedule(audio->timing, &audio->ch2Event, when);
1004 }
1005
1006 audio->ch3.readable = GBSerializedAudioFlagsGetCh3Readable(flags);
1007 // TODO: Big endian?
1008 memcpy(audio->ch3.wavedata32, state->ch3.wavebanks, sizeof(audio->ch3.wavedata32));
1009 LOAD_16LE(audio->ch3.length, 0, &state->ch3.length);
1010 LOAD_32LE(when, 0, &state->ch3.nextEvent);
1011 if (audio->playingCh3) {
1012 mTimingSchedule(audio->timing, &audio->ch3Event, when);
1013 }
1014 LOAD_32LE(when, 0, &state->ch1.nextCh3Fade);
1015 if (audio->ch3.readable && audio->style == GB_AUDIO_DMG) {
1016 mTimingSchedule(audio->timing, &audio->ch3Fade, when);
1017 }
1018
1019 LOAD_32LE(ch4Flags, 0, &state->ch4.envelope);
1020 audio->ch4.envelope.currentVolume = GBSerializedAudioFlagsGetCh4Volume(flags);
1021 audio->ch4.envelope.dead = GBSerializedAudioFlagsGetCh4Dead(flags);
1022 audio->ch4.length = GBSerializedAudioEnvelopeGetLength(ch4Flags);
1023 audio->ch4.envelope.nextStep = GBSerializedAudioEnvelopeGetNextStep(ch4Flags);
1024 LOAD_32LE(audio->ch4.lfsr, 0, &state->ch4.lfsr);
1025 LOAD_32LE(when, 0, &state->ch4.nextEvent);
1026 if (audio->ch4.envelope.dead < 2 && audio->playingCh4) {
1027 mTimingSchedule(audio->timing, &audio->ch4Event, when);
1028 }
1029}
1030
1031void GBAudioSerialize(const struct GBAudio* audio, struct GBSerializedState* state) {
1032 GBAudioPSGSerialize(audio, &state->audio.psg, &state->audio.flags);
1033 STORE_32LE(audio->capLeft, 0, &state->audio.capLeft);
1034 STORE_32LE(audio->capRight, 0, &state->audio.capRight);
1035 STORE_32LE(audio->sampleEvent.when - mTimingCurrentTime(audio->timing), 0, &state->audio.nextSample);
1036}
1037
1038void GBAudioDeserialize(struct GBAudio* audio, const struct GBSerializedState* state) {
1039 GBAudioPSGDeserialize(audio, &state->audio.psg, &state->audio.flags);
1040 LOAD_32LE(audio->capLeft, 0, &state->audio.capLeft);
1041 LOAD_32LE(audio->capRight, 0, &state->audio.capRight);
1042 uint32_t when;
1043 LOAD_32LE(when, 0, &state->audio.nextSample);
1044 mTimingSchedule(audio->timing, &audio->sampleEvent, when);
1045}