vrshoot: b2f14e535253 src/audio/stream.cc

vrshoot

view src/audio/stream.cc @ 0:b2f14e535253

initial commit

author	John Tsiombikas <nuclear@member.fsf.org>
date	Sat, 01 Feb 2014 19:58:19 +0200
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line source

1 #include <stdio.h>

2 #include <stdint.h>

3 #include <assert.h>

4 #include "openal.h"

5 #include "stream.h"

6 #include "logger.h"

7 #include "timer.h"

8 #include "kiss_fft.h"

10 struct FFTState {

11 kiss_fft_cfg kiss;

12 kiss_fft_cpx *inbuf, *outbuf;

13 int nsamples;

14 };

16 static ALenum alformat(AudioStreamBuffer *buf)

17 {

18 return buf->channels == 1 ? AL_FORMAT_MONO16 : AL_FORMAT_STEREO16;

19 }

21 AudioStream::AudioStream()

22 {

23 alsrc = 0;

24 poll_interval = 25;

25 done = true;

26 loop = false;

27 volume = 1.0;

29 freqhist = 0;

31 // by default disable FFT processing

32 use_fft = false;

34 pthread_mutex_init(&mutex, 0);

35 }

37 AudioStream::~AudioStream()

38 {

39 stop();

40 }

42 void AudioStream::enable_fft()

43 {

44 use_fft = true;

45 }

47 void AudioStream::disable_fft()

48 {

49 use_fft = false;

50 }

52 bool AudioStream::is_fft_enabled() const

53 {

54 return use_fft;

55 }

57 bool AudioStream::open(const char *fname)

58 {

59 return false;

60 }

62 void AudioStream::close()

63 {

64 }

66 void AudioStream::set_volume(float vol)

67 {

68 volume = vol;

70 pthread_mutex_lock(&mutex);

71 if(alsrc) {

72 alSourcef(alsrc, AL_GAIN, vol);

73 }

74 pthread_mutex_unlock(&mutex);

75 }

77 float AudioStream::get_volume() const

78 {

79 return volume;

80 }

82 static void *thread_func(void *arg)

83 {

84 AudioStream *astr = (AudioStream*)arg;

85 astr->poll_loop();

86 return 0;

87 }

89 void AudioStream::play(AUDIO_PLAYMODE mode)

90 {

91 loop = (mode == AUDIO_PLAYMODE_LOOP);

92 done = false;

94 if(pthread_create(&play_thread, 0, thread_func, this) != 0) {

95 error_log("failed to create music playback thread\n");

96 }

97 }

99 void AudioStream::stop()

100 {

101 pthread_mutex_lock(&mutex);

102

103 if(alsrc) {

104 done = true;

105 alSourceStop(alsrc);

106 printf("waiting for the music thread to stop\n");

107 pthread_mutex_unlock(&mutex);

108 pthread_join(play_thread, 0);

109 } else {

110 pthread_mutex_unlock(&mutex);

111 }

112 }

113

114 // gets an array of buffers and returns the index of the one matching id

115 static inline int find_buffer(unsigned int id, unsigned int *barr, int num)

116 {

117 for(int i=0; i<num; i++) {

118 if(barr[i] == id) {

119 return i;

120 }

121 }

122 return -1;

123 }

124

125

126 static int queued_idx_list[AUDIO_NUM_BUFFERS];

127 static int queued_idx_head = 0;

128 static int queued_idx_tail = 0;

129

130 #define BUFQ_UNQUEUE() \

131 do { \

132 queued_idx_tail = (queued_idx_tail + 1) % AUDIO_NUM_BUFFERS; \

133 } while(0)

134

135

136 #define BUFQ_QUEUE(idx) \

137 do { \

138 queued_idx_head = (queued_idx_head + 1) % AUDIO_NUM_BUFFERS; \

139 queued_idx_list[queued_idx_head] = idx; \

140 } while(0)

141

142 // thread function

143 void AudioStream::poll_loop()

144 {

145 long prev_msec = -1000;

146 unsigned int albuf[AUDIO_NUM_BUFFERS];

147 int freqbins[AUDIO_NUM_BUFFERS][AUDIO_FFT_BINS];

148

149 pthread_mutex_lock(&mutex);

150 alGenSources(1, &alsrc);

151 alSourcei(alsrc, AL_LOOPING, AL_FALSE);

152 alSourcef(alsrc, AL_GAIN, volume);

153 alGenBuffers(AUDIO_NUM_BUFFERS, albuf);

154 AudioStreamBuffer *buf = new AudioStreamBuffer;

155

156 FFTState fft;

157 fft.kiss = kiss_fft_alloc(AUDIO_FFT_SAMPLES, 0, 0, 0);

158 assert(fft.kiss);

159 fft.inbuf = new kiss_fft_cpx[AUDIO_FFT_SAMPLES];

160 fft.outbuf = new kiss_fft_cpx[AUDIO_FFT_SAMPLES];

161 assert(fft.inbuf && fft.outbuf);

162 fft.nsamples = AUDIO_FFT_SAMPLES;

163

164 // zero out the inbuf array to get rid of the imaginary parts

165 memset(fft.inbuf, 0, AUDIO_FFT_SAMPLES * sizeof *fft.inbuf);

166

167 for(int i=0; i<AUDIO_NUM_BUFFERS; i++) {

168 if(more_samples(buf)) {

169 int bufsz = buf->num_samples * buf->channels * 2; // 2 is for 16bit samples

170 alBufferData(albuf[i], alformat(buf), buf->samples, bufsz, buf->sample_rate);

171

172 if(alGetError()) {

173 fprintf(stderr, "failed to load sample data into OpenAL buffer\n");

174 }

175

176 alSourceQueueBuffers(alsrc, 1, albuf + i);

177 BUFQ_QUEUE(i);

178

179 if(alGetError()) {

180 fprintf(stderr, "failed to start streaming audio buffers\n");

181 }

182

183 // also calculate the frequencies

184 calc_freq(buf, freqbins[i], &fft);

185 } else {

186 break;

187 }

188 }

189

190 // start playback

191 alSourcePlay(alsrc);

192 while(!done) {

193 // XXX this doesn't work

194 /*

195 // first let's figure out which buffer is currently playing

196 int cur_buf;

197 alGetSourcei(alsrc, AL_BUFFER, &cur_buf);

198 int cur_buf_idx = find_buffer(cur_buf, albuf, AUDIO_NUM_BUFFERS);

199

200 // make the fft histogram pointer point to the correct frequency bin array

201 freqhist = cur_buf_idx != -1 ? freqbins[cur_buf_idx] : 0;

202 if(!freqhist) {

203 debug_log("skata\n");

204 }

205 */

206

207 /* find out how many (if any) of the queued buffers are

208 * done, and free to be reused.

209 */

210 int num_buf_done;

211 alGetSourcei(alsrc, AL_BUFFERS_PROCESSED, &num_buf_done);

212 for(int i=0; i<num_buf_done; i++) {

213 int err;

214 // unqueue a buffer...

215 unsigned int buf_id;

216 alSourceUnqueueBuffers(alsrc, 1, &buf_id);

217

218 if((err = alGetError())) {

219 fprintf(stderr, "failed to unqueue used buffer (error: %x)\n", err);

220 num_buf_done = i;

221 break;

222 }

223 BUFQ_UNQUEUE();

224

225 // find out which one of our al buffers we just unqueued

226 int bidx = find_buffer(buf_id, albuf, AUDIO_NUM_BUFFERS);

227 assert(bidx != -1);

228

229 int looping;

230

231 alGetSourcei(alsrc, AL_LOOPING, &looping);

232 assert(looping == AL_FALSE);

233 /*if((unsigned int)cur_buf == buf_id) {

234 continue;

235 }*/

236

237 // if there are more data, fill it up and requeue it

238 if(more_samples(buf)) {

239 int bufsz = buf->num_samples * buf->channels * 2; // 2 is for 16bit samples

240 alBufferData(buf_id, alformat(buf), buf->samples, bufsz, buf->sample_rate);

241 if((err = alGetError())) {

242 fprintf(stderr, "failed to load sample data into OpenAL buffer (error: %x)\n", err);

243 }

244

245 alSourceQueueBuffers(alsrc, 1, &buf_id);

246 if(alGetError()) {

247 fprintf(stderr, "failed to start streaming audio buffers\n");

248 }

249 BUFQ_QUEUE(bidx);

250

251 // also calculate the frequencies if required

252 if(use_fft) {

253 calc_freq(buf, freqbins[bidx], &fft);

254 }

255 } else {

256 // no more data...

257 if(loop) {

258 rewind();

259 } else {

260 done = true;

261 }

262 }

263 }

264 if(use_fft) {

265 freqhist = freqbins[queued_idx_list[queued_idx_tail]];

266 }

267

268 if(num_buf_done) {

269 // make sure playback didn't stop

270 int state;

271 alGetSourcei(alsrc, AL_SOURCE_STATE, &state);

272 if(state != AL_PLAYING) {

273 alSourcePlay(alsrc);

274 }

275 }

276

277 pthread_mutex_unlock(&mutex);

278 long msec = get_time_msec();

279 long dt = msec - prev_msec;

280 prev_msec = msec;

281

282 if(dt < poll_interval - 5) {

283 sleep_msec(poll_interval - dt);

284 } else {

285 sched_yield();

286 }

287 pthread_mutex_lock(&mutex);

288 }

289

290

291 // done with the data, wait for the source to stop playing before cleanup

292 int state;

293 while(alGetSourcei(alsrc, AL_SOURCE_STATE, &state), state == AL_PLAYING) {

294 sched_yield();

295 }

296

297 freqhist = 0;

298

299 alDeleteBuffers(AUDIO_NUM_BUFFERS, albuf);

300 alDeleteSources(1, &alsrc);

301 alsrc = 0;

302 pthread_mutex_unlock(&mutex);

303

304 delete buf;

305

306 delete [] fft.inbuf;

307 delete [] fft.outbuf;

308 kiss_fft_free(fft.kiss);

309 }

310

311 int AudioStream::freq_count(int bin) const

312 {

313 if(!freqhist || !use_fft || bin < 0 || bin >= AUDIO_BUFFER_SAMPLES) {

314 return 0;

315 }

316 return freqhist[bin];

317 }

318

319 #define NORM_FACTOR (1.0f / (float)AUDIO_FFT_SAMPLES)

320 float AudioStream::freq_normalized(int bin) const

321 {

322 // TODO remove the fudge factor

323 return freq_count(bin) * NORM_FACTOR * 0.25;

324 }

325

326 // frequency range in hertz

327 int AudioStream::freq_count(int range_start, int range_end) const

328 {

329 // NOTE this will probably be something like sampling freq / num-bins Hz per bin...

330 return 0; // TODO

331 }

332

333 // TODO ok this might be inefficient, copying the data around a lot, optimize later

334 void AudioStream::calc_freq(AudioStreamBuffer *buf, int *bins, FFTState *fft)

335 {

336 kiss_fft_cpx *inptr = fft->inbuf;

337 int16_t *samples = (int16_t*)buf->samples;

338 for(int i=0; i<AUDIO_BUFFER_SAMPLES; i++) {

339

340 inptr->i = 0;

341 if(i < buf->num_samples) {

342 int left = samples[i * 2];

343 int right = samples[i * 2 + 1];

344

345 (inptr++)->r = (left + right) / 2;

346 } else {

347 (inptr++)->r = 0;

348 }

349 }

350

351 kiss_fft(fft->kiss, fft->inbuf, fft->outbuf);

352

353 // then copy all the relevant data to the bins array

354 int num_out_samples = AUDIO_BUFFER_SAMPLES / 2;

355 int samples_per_bin = num_out_samples / AUDIO_FFT_BINS;

356

357 long abins[AUDIO_FFT_BINS];

358

359 int prev_bidx = -1;

360 // ignore the DC bin (0)

361 for(int i=1; i<num_out_samples; i++) {

362 int bidx = i * AUDIO_FFT_BINS / num_out_samples;

363 float x = fft->outbuf[i].r;

364 float y = fft->outbuf[i].i;

365 int val = x * x + y * y;

366

367 if(bidx != prev_bidx) {

368 abins[bidx] = val;

369 prev_bidx = bidx;

370 } else {

371 abins[bidx] += val;

372 }

373 }

374

375 for(int i=0; i<AUDIO_FFT_BINS; i++) {

376 long res = abins[i] / (long)samples_per_bin;

377 bins[i] = res;

378 assert(bins[i] == res);

379 }

380 }