all repos — mgba @ 0cf9bf75e28e632ca071bb59a15e4f1afa4b4b9c

mGBA Game Boy Advance Emulator

src/ds/audio.c (view raw)

  1/* Copyright (c) 2013-2017 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/ds/audio.h>
  7
  8#include <mgba/core/blip_buf.h>
  9#include <mgba/core/sync.h>
 10#include <mgba/internal/ds/ds.h>
 11
 12mLOG_DEFINE_CATEGORY(DS_AUDIO, "DS Audio", "ds.audio");
 13
 14static const unsigned BLIP_BUFFER_SIZE = 0x4000;
 15static const int CLOCKS_PER_FRAME = 0x4000;
 16const int DS_AUDIO_VOLUME_MAX = 0x100;
 17
 18static void _updateChannel(struct mTiming* timing, void* user, uint32_t cyclesLate);
 19static void _sample(struct mTiming* timing, void* user, uint32_t cyclesLate);
 20static void _updateMixer(struct DSAudio*);
 21
 22static const int _adpcmIndexTable[8] = {
 23	-1, -1, -1, -1, 2, 4, 6, 8
 24};
 25
 26static const uint16_t _adpcmTable[89] = {
 27	0x0007, 0x0008, 0x0009, 0x000A, 0x000B, 0x000C, 0x000D, 0x000E, 0x0010, 0x0011, 0x0013, 0x0015,
 28	0x0017, 0x0019, 0x001C, 0x001F, 0x0022, 0x0025, 0x0029, 0x002D, 0x0032, 0x0037, 0x003C, 0x0042,
 29	0x0049, 0x0050, 0x0058, 0x0061, 0x006B, 0x0076, 0x0082, 0x008F, 0x009D, 0x00AD, 0x00BE, 0x00D1,
 30	0x00E6, 0x00FD, 0x0117, 0x0133, 0x0151, 0x0173, 0x0198, 0x01C1, 0x01EE, 0x0220, 0x0256, 0x0292,
 31	0x02D4, 0x031C, 0x036C, 0x03C3, 0x0424, 0x048E, 0x0502, 0x0583, 0x0610, 0x06AB, 0x0756, 0x0812,
 32	0x08E0, 0x09C3, 0x0ABD, 0x0BD0, 0x0CFF, 0x0E4C, 0x0FBA, 0x114C, 0x1307, 0x14EE, 0x1706, 0x1954,
 33	0x1BDC, 0x1EA5, 0x21B6, 0x2515, 0x28CA, 0x2CDF, 0x315B, 0x364B, 0x3BB9, 0x41B2, 0x4844, 0x4F7E,
 34	0x5771, 0x602F, 0x69CE, 0x7462, 0x7FFF
 35};
 36
 37void DSAudioInit(struct DSAudio* audio, size_t samples) {
 38	audio->samples = samples;
 39	audio->left = blip_new(BLIP_BUFFER_SIZE);
 40	audio->right = blip_new(BLIP_BUFFER_SIZE);
 41
 42	audio->ch[0].updateEvent.name = "DS Audio Channel 0";
 43	audio->ch[1].updateEvent.name = "DS Audio Channel 1";
 44	audio->ch[2].updateEvent.name = "DS Audio Channel 2";
 45	audio->ch[3].updateEvent.name = "DS Audio Channel 3";
 46	audio->ch[4].updateEvent.name = "DS Audio Channel 4";
 47	audio->ch[5].updateEvent.name = "DS Audio Channel 5";
 48	audio->ch[6].updateEvent.name = "DS Audio Channel 6";
 49	audio->ch[7].updateEvent.name = "DS Audio Channel 7";
 50	audio->ch[8].updateEvent.name = "DS Audio Channel 8";
 51	audio->ch[9].updateEvent.name = "DS Audio Channel 9";
 52	audio->ch[10].updateEvent.name = "DS Audio Channel 10";
 53	audio->ch[11].updateEvent.name = "DS Audio Channel 11";
 54	audio->ch[12].updateEvent.name = "DS Audio Channel 12";
 55	audio->ch[13].updateEvent.name = "DS Audio Channel 13";
 56	audio->ch[14].updateEvent.name = "DS Audio Channel 14";
 57	audio->ch[15].updateEvent.name = "DS Audio Channel 15";
 58
 59	int ch;
 60	for (ch = 0; ch < 16; ++ch) {
 61		audio->ch[ch].index = ch;
 62		audio->ch[ch].updateEvent.priority = 0x10 | ch;
 63		audio->ch[ch].updateEvent.context = &audio->ch[ch];
 64		audio->ch[ch].updateEvent.callback = _updateChannel;
 65		audio->ch[ch].p = audio;
 66		audio->forceDisableCh[ch] = false;
 67	}
 68	audio->masterVolume = DS_AUDIO_VOLUME_MAX;
 69
 70	audio->sampleEvent.name = "DS Audio Sample";
 71	audio->sampleEvent.context = audio;
 72	audio->sampleEvent.callback = _sample;
 73	audio->sampleEvent.priority = 0x110;
 74
 75	blip_set_rates(audio->left, DS_ARM7TDMI_FREQUENCY, 96000);
 76	blip_set_rates(audio->right, DS_ARM7TDMI_FREQUENCY, 96000);
 77}
 78
 79void DSAudioDeinit(struct DSAudio* audio) {
 80	blip_delete(audio->left);
 81	blip_delete(audio->right);
 82}
 83
 84void DSAudioReset(struct DSAudio* audio) {
 85	mTimingDeschedule(&audio->p->ds7.timing, &audio->sampleEvent);
 86	mTimingSchedule(&audio->p->ds7.timing, &audio->sampleEvent, 0);
 87	audio->sampleRate = 0x8000;
 88	audio->sampleInterval = DS_ARM7TDMI_FREQUENCY / audio->sampleRate;
 89
 90	int ch;
 91	for (ch = 0; ch < 16; ++ch) {
 92		audio->ch[ch].source = 0;
 93		audio->ch[ch].loopPoint = 0;
 94		audio->ch[ch].length = 0;
 95		audio->ch[ch].offset = 0;
 96		audio->ch[ch].sample = 0;
 97		audio->ch[ch].adpcmOffset = 0;
 98		audio->ch[ch].adpcmStartSample = 0;
 99		audio->ch[ch].adpcmStartIndex = 0;
100		audio->ch[ch].adpcmSample = 0;
101		audio->ch[ch].adpcmIndex = 0;
102	}
103
104	blip_clear(audio->left);
105	blip_clear(audio->right);
106	audio->clock = 0;
107	audio->bias = 0x200;
108}
109
110void DSAudioResizeBuffer(struct DSAudio* audio, size_t samples) {
111	// TODO: Share between other cores
112	mCoreSyncLockAudio(audio->p->sync);
113	audio->samples = samples;
114	blip_clear(audio->left);
115	blip_clear(audio->right);
116	audio->clock = 0;
117	mCoreSyncConsumeAudio(audio->p->sync);
118}
119
120void DSAudioWriteSOUNDCNT_LO(struct DSAudio* audio, int chan, uint16_t value) {
121	audio->ch[chan].volume = DSRegisterSOUNDxCNTGetVolumeMul(value);
122	audio->ch[chan].divider = DSRegisterSOUNDxCNTGetVolumeDiv(value);
123	if (audio->ch[chan].divider == 3) {
124		++audio->ch[chan].divider;
125	}
126}
127
128void DSAudioWriteSOUNDCNT_HI(struct DSAudio* audio, int chan, uint16_t value) {
129	DSRegisterSOUNDxCNT reg = value << 16;
130	struct DSAudioChannel* ch = &audio->ch[chan];
131
132	ch->panning = DSRegisterSOUNDxCNTGetPanning(reg);
133	ch->repeat = DSRegisterSOUNDxCNTGetRepeat(reg);
134	ch->format = DSRegisterSOUNDxCNTGetFormat(reg);
135
136	if (ch->format > 2) {
137		mLOG(DS_AUDIO, STUB, "Unimplemented audio format %i", ch->format);
138	}
139
140	if (ch->enable && !DSRegisterSOUNDxCNTIsBusy(reg)) {
141		mTimingDeschedule(&audio->p->ds7.timing, &ch->updateEvent);
142	} else if (!ch->enable && DSRegisterSOUNDxCNTIsBusy(reg)) {
143		ch->offset = 0;
144		mTimingDeschedule(&audio->p->ds7.timing, &ch->updateEvent);
145		mTimingSchedule(&audio->p->ds7.timing, &ch->updateEvent, 0);
146		if (ch->format == 2) {
147			uint32_t header = audio->p->ds7.cpu->memory.load32(audio->p->ds7.cpu, ch->source, NULL);
148			ch->offset += 4;
149			ch->adpcmStartSample = header &= 0xFFFF;
150			ch->adpcmStartIndex = header >> 16;
151		}
152	}
153	ch->enable = DSRegisterSOUNDxCNTIsBusy(reg);
154}
155
156void DSAudioWriteSOUNDTMR(struct DSAudio* audio, int chan, uint16_t value) {
157	audio->ch[chan].period = (0x10000 - value) << 1;
158}
159
160void DSAudioWriteSOUNDPNT(struct DSAudio* audio, int chan, uint16_t value) {
161	audio->ch[chan].loopPoint = value << 2;
162}
163
164void DSAudioWriteSOUNDSAD(struct DSAudio* audio, int chan, uint32_t value) {
165	audio->ch[chan].source = value;
166}
167
168void DSAudioWriteSOUNDLEN(struct DSAudio* audio, int chan, uint32_t value) {
169	audio->ch[chan].length = value << 2;
170}
171
172static void _updateMixer(struct DSAudio* audio) {
173	int32_t sampleLeft = 0;
174	int32_t sampleRight = 0;
175	int ch;
176	for (ch = 0; ch < 16; ++ch) {
177		if (!audio->ch[ch].enable) {
178			continue;
179		}
180		int32_t sample = audio->ch[ch].sample << 4;
181		sample >>= audio->ch[ch].divider;
182		sample *= audio->ch[ch].volume;
183		sample >>= 2;
184
185		int32_t left = sample * (0x7F - audio->ch[ch].panning);
186		int32_t right = sample * audio->ch[ch].panning;
187		sampleLeft += left >>= 16;
188		sampleRight += right >>= 16;
189	}
190	audio->sampleLeft = sampleLeft >> 6;
191	audio->sampleRight = sampleRight >> 6;
192}
193
194static void _updateAdpcm(struct DSAudioChannel* ch, int sample) {
195	if (ch->adpcmIndex < 0) {
196		ch->adpcmIndex = 0;
197	} else if (ch->adpcmIndex > 88) {
198		ch->adpcmIndex = 88;
199	}
200	int16_t diff = _adpcmTable[ch->adpcmIndex] >> 3;
201	if (sample & 1) {
202		diff += _adpcmTable[ch->adpcmIndex] >> 2;
203	}
204	if (sample & 2) {
205		diff += _adpcmTable[ch->adpcmIndex] >> 1;
206	}
207	if (sample & 4) {
208		diff += _adpcmTable[ch->adpcmIndex];
209	}
210	if (sample & 8) {
211		int32_t newSample = ch->adpcmSample - diff;
212		if (newSample < -0x7FFF) {
213			ch->adpcmSample = -0x7FFF;
214		} else {
215			ch->adpcmSample = newSample;
216		}
217	} else {
218		int32_t newSample = ch->adpcmSample + diff;
219		if (newSample > 0x7FFF) {
220			ch->adpcmSample = 0x7FFF;
221		} else {
222			ch->adpcmSample = newSample;
223		}
224	}
225	ch->sample = ch->adpcmSample;
226	ch->adpcmIndex += _adpcmIndexTable[sample & 0x7];
227}
228
229static void _updateChannel(struct mTiming* timing, void* user, uint32_t cyclesLate) {
230	struct DSAudioChannel* ch = user;
231	struct ARMCore* cpu = ch->p->p->ds7.cpu;
232	switch (ch->format) {
233	case 0:
234		ch->sample = cpu->memory.load8(cpu, ch->offset + ch->source, NULL) << 8;
235		++ch->offset;
236		break;
237	case 1:
238		ch->sample = cpu->memory.load16(cpu, ch->offset + ch->source, NULL);
239		ch->offset += 2;
240		break;
241	case 2:
242		_updateAdpcm(ch, (cpu->memory.load8(cpu, ch->offset + ch->source, NULL) >> ch->adpcmOffset) & 0xF);
243		ch->offset += ch->adpcmOffset >> 2;
244		ch->adpcmOffset ^= 4;
245		if (ch->offset == ch->loopPoint && !ch->adpcmOffset) {
246			ch->adpcmStartSample = ch->adpcmSample;
247			ch->adpcmStartIndex = ch->adpcmIndex;
248		}
249		break;
250	}
251	_updateMixer(ch->p);
252	switch (ch->repeat) {
253	case 1:
254		if (ch->offset >= ch->length + ch->loopPoint) {
255			ch->offset = ch->loopPoint;
256			if (ch->format == 2) {
257				ch->adpcmSample = ch->adpcmStartSample;
258				ch->adpcmIndex = ch->adpcmStartIndex;
259			}
260		}
261		break;
262	case 2:
263		if (ch->offset >= ch->length + ch->loopPoint) {
264			ch->enable = false;
265			ch->p->p->memory.io7[(DS7_REG_SOUND0CNT_HI + (ch->index << 4)) >> 1] &= 0x7FFF;
266		}
267		break;
268	}
269	if (ch->enable) {
270		mTimingSchedule(timing, &ch->updateEvent, ch->period - cyclesLate);
271	}
272}
273
274static int _applyBias(struct DSAudio* audio, int sample) {
275	sample += audio->bias;
276	if (sample >= 0x400) {
277		sample = 0x3FF;
278	} else if (sample < 0) {
279		sample = 0;
280	}
281	return ((sample - audio->bias) * audio->masterVolume) >> 3;
282}
283
284static void _sample(struct mTiming* timing, void* user, uint32_t cyclesLate) {
285	struct DSAudio* audio = user;
286
287	int16_t sampleLeft = _applyBias(audio, audio->sampleLeft);
288	int16_t sampleRight = _applyBias(audio, audio->sampleRight);
289
290	mCoreSyncLockAudio(audio->p->sync);
291	unsigned produced;
292	if ((size_t) blip_samples_avail(audio->left) < audio->samples) {
293		blip_add_delta(audio->left, audio->clock, sampleLeft - audio->lastLeft);
294		blip_add_delta(audio->right, audio->clock, sampleRight - audio->lastRight);
295		audio->lastLeft = sampleLeft;
296		audio->lastRight = sampleRight;
297		audio->clock += audio->sampleInterval;
298		if (audio->clock >= CLOCKS_PER_FRAME) {
299			blip_end_frame(audio->left, audio->clock);
300			blip_end_frame(audio->right, audio->clock);
301			audio->clock -= CLOCKS_PER_FRAME;
302		}
303	}
304	produced = blip_samples_avail(audio->left);
305	if (audio->p->stream && audio->p->stream->postAudioFrame) {
306		audio->p->stream->postAudioFrame(audio->p->stream, sampleLeft, sampleRight);
307	}
308	bool wait = produced >= audio->samples;
309	mCoreSyncProduceAudio(audio->p->sync, wait);
310
311	if (wait && audio->p->stream && audio->p->stream->postAudioBuffer) {
312		audio->p->stream->postAudioBuffer(audio->p->stream, audio->left, audio->right);
313	}
314	mTimingSchedule(timing, &audio->sampleEvent, audio->sampleInterval - cyclesLate);
315}