all repos — mgba @ 91eb813e564f9ddd1b60dfc371b2a6c793e46e14

mGBA Game Boy Advance Emulator

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