1/* 2** Copyright 2011, The Android Open-Source Project 3** 4** Licensed under the Apache License, Version 2.0 (the "License"); 5** you may not use this file except in compliance with the License. 6** You may obtain a copy of the License at 7** 8** http://www.apache.org/licenses/LICENSE-2.0 9** 10** Unless required by applicable law or agreed to in writing, software 11** distributed under the License is distributed on an "AS IS" BASIS, 12** WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 13** See the License for the specific language governing permissions and 14** limitations under the License. 15*/ 16 17//#define LOG_NDEBUG 0 18#define LOG_TAG "echo_reference" 19 20#include <errno.h> 21#include <inttypes.h> 22#include <pthread.h> 23#include <stdlib.h> 24 25#include <log/log.h> 26#include <system/audio.h> 27#include <audio_utils/resampler.h> 28#include <audio_utils/echo_reference.h> 29 30// echo reference state: bit field indicating if read, write or both are active. 31enum state { 32 ECHOREF_IDLE = 0x00, // idle 33 ECHOREF_READING = 0x01, // reading is active 34 ECHOREF_WRITING = 0x02 // writing is active 35}; 36 37struct echo_reference { 38 struct echo_reference_itfe itfe; 39 int status; // init status 40 uint32_t state; // active state: reading, writing or both 41 audio_format_t rd_format; // read sample format 42 uint32_t rd_channel_count; // read number of channels 43 uint32_t rd_sampling_rate; // read sampling rate in Hz 44 size_t rd_frame_size; // read frame size (bytes per sample) 45 audio_format_t wr_format; // write sample format 46 uint32_t wr_channel_count; // write number of channels 47 uint32_t wr_sampling_rate; // write sampling rate in Hz 48 size_t wr_frame_size; // write frame size (bytes per sample) 49 void *buffer; // main buffer 50 size_t buf_size; // main buffer size in frames 51 size_t frames_in; // number of frames in main buffer 52 void *wr_buf; // buffer for input conversions 53 size_t wr_buf_size; // size of conversion buffer in frames 54 size_t wr_frames_in; // number of frames in conversion buffer 55 size_t wr_curr_frame_size; // number of frames given to current write() function 56 void *wr_src_buf; // resampler input buf (either wr_buf or buffer used by write()) 57 struct timespec wr_render_time; // latest render time indicated by write() 58 // default ALSA gettimeofday() format 59 int32_t playback_delay; // playback buffer delay indicated by last write() 60 int16_t prev_delta_sign; // sign of previous delay difference: 61 // 1: positive, -1: negative, 0: unknown 62 uint16_t delta_count; // number of consecutive delay differences with same sign 63 pthread_mutex_t lock; // mutex protecting read/write concurrency 64 pthread_cond_t cond; // condition signaled when data is ready to read 65 struct resampler_itfe *resampler; // input resampler 66 struct resampler_buffer_provider provider; // resampler buffer provider 67}; 68 69 70int echo_reference_get_next_buffer(struct resampler_buffer_provider *buffer_provider, 71 struct resampler_buffer* buffer) 72{ 73 struct echo_reference *er; 74 75 if (buffer_provider == NULL) { 76 return -EINVAL; 77 } 78 79 er = (struct echo_reference *)((char *)buffer_provider - 80 offsetof(struct echo_reference, provider)); 81 82 if (er->wr_src_buf == NULL || er->wr_frames_in == 0) { 83 buffer->raw = NULL; 84 buffer->frame_count = 0; 85 return -ENODATA; 86 } 87 88 buffer->frame_count = (buffer->frame_count > er->wr_frames_in) ? 89 er->wr_frames_in : buffer->frame_count; 90 // this is er->rd_channel_count here as we resample after stereo to mono conversion if any 91 buffer->i16 = (int16_t *)er->wr_src_buf + (er->wr_curr_frame_size - er->wr_frames_in) * 92 er->rd_channel_count; 93 94 return 0; 95} 96 97void echo_reference_release_buffer(struct resampler_buffer_provider *buffer_provider, 98 struct resampler_buffer* buffer) 99{ 100 struct echo_reference *er; 101 102 if (buffer_provider == NULL) { 103 return; 104 } 105 106 er = (struct echo_reference *)((char *)buffer_provider - 107 offsetof(struct echo_reference, provider)); 108 109 er->wr_frames_in -= buffer->frame_count; 110} 111 112static void echo_reference_reset_l(struct echo_reference *er) 113{ 114 ALOGV("echo_reference_reset_l()"); 115 free(er->buffer); 116 er->buffer = NULL; 117 er->buf_size = 0; 118 er->frames_in = 0; 119 free(er->wr_buf); 120 er->wr_buf = NULL; 121 er->wr_buf_size = 0; 122 er->wr_render_time.tv_sec = 0; 123 er->wr_render_time.tv_nsec = 0; 124 er->delta_count = 0; 125 er->prev_delta_sign = 0; 126} 127 128/* additional space in resampler buffer allowing for extra samples to be returned 129 * by speex resampler when sample rates ratio is not an integer. 130 */ 131#define RESAMPLER_HEADROOM_SAMPLES 10 132 133static int echo_reference_write(struct echo_reference_itfe *echo_reference, 134 struct echo_reference_buffer *buffer) 135{ 136 struct echo_reference *er = (struct echo_reference *)echo_reference; 137 int status = 0; 138 139 if (er == NULL) { 140 return -EINVAL; 141 } 142 143 pthread_mutex_lock(&er->lock); 144 145 if (buffer == NULL) { 146 ALOGV("echo_reference_write() stop write"); 147 er->state &= ~ECHOREF_WRITING; 148 echo_reference_reset_l(er); 149 goto exit; 150 } 151 152 ALOGV("echo_reference_write() START trying to write %zu frames", buffer->frame_count); 153 ALOGV("echo_reference_write() playbackTimestamp:[%d].[%d], er->playback_delay:[%" PRId32 "]", 154 (int)buffer->time_stamp.tv_sec, 155 (int)buffer->time_stamp.tv_nsec, er->playback_delay); 156 157 //ALOGV("echo_reference_write() %d frames", buffer->frame_count); 158 // discard writes until a valid time stamp is provided. 159 160 if ((buffer->time_stamp.tv_sec == 0) && (buffer->time_stamp.tv_nsec == 0) && 161 (er->wr_render_time.tv_sec == 0) && (er->wr_render_time.tv_nsec == 0)) { 162 goto exit; 163 } 164 165 if ((er->state & ECHOREF_WRITING) == 0) { 166 ALOGV("echo_reference_write() start write"); 167 if (er->resampler != NULL) { 168 er->resampler->reset(er->resampler); 169 } 170 er->state |= ECHOREF_WRITING; 171 } 172 173 if ((er->state & ECHOREF_READING) == 0) { 174 goto exit; 175 } 176 177 er->wr_render_time.tv_sec = buffer->time_stamp.tv_sec; 178 er->wr_render_time.tv_nsec = buffer->time_stamp.tv_nsec; 179 180 er->playback_delay = buffer->delay_ns; 181 182 // this will be used in the get_next_buffer, to support variable input buffer sizes 183 er->wr_curr_frame_size = buffer->frame_count; 184 185 void *srcBuf; 186 size_t inFrames; 187 // do stereo to mono and down sampling if necessary 188 if (er->rd_channel_count != er->wr_channel_count || 189 er->rd_sampling_rate != er->wr_sampling_rate) { 190 size_t wrBufSize = buffer->frame_count; 191 192 inFrames = buffer->frame_count; 193 194 if (er->rd_sampling_rate != er->wr_sampling_rate) { 195 inFrames = (buffer->frame_count * er->rd_sampling_rate) / er->wr_sampling_rate + 196 RESAMPLER_HEADROOM_SAMPLES; 197 // wr_buf is not only used as resampler output but also for stereo to mono conversion 198 // output so buffer size is driven by both write and read sample rates 199 if (inFrames > wrBufSize) { 200 wrBufSize = inFrames; 201 } 202 } 203 204 if (er->wr_buf_size < wrBufSize) { 205 ALOGV("echo_reference_write() increasing write buffer size from %zu to %zu", 206 er->wr_buf_size, wrBufSize); 207 er->wr_buf_size = wrBufSize; 208 er->wr_buf = realloc(er->wr_buf, er->wr_buf_size * er->rd_frame_size); 209 } 210 211 if (er->rd_channel_count != er->wr_channel_count) { 212 // must be stereo to mono 213 int16_t *src16 = (int16_t *)buffer->raw; 214 int16_t *dst16 = (int16_t *)er->wr_buf; 215 size_t frames = buffer->frame_count; 216 while (frames--) { 217 *dst16++ = (int16_t)(((int32_t)*src16 + (int32_t)*(src16 + 1)) >> 1); 218 src16 += 2; 219 } 220 } 221 if (er->wr_sampling_rate != er->rd_sampling_rate) { 222 if (er->resampler == NULL) { 223 int rc; 224 ALOGV("echo_reference_write() new ReSampler(%d, %d)", 225 er->wr_sampling_rate, er->rd_sampling_rate); 226 er->provider.get_next_buffer = echo_reference_get_next_buffer; 227 er->provider.release_buffer = echo_reference_release_buffer; 228 rc = create_resampler(er->wr_sampling_rate, 229 er->rd_sampling_rate, 230 er->rd_channel_count, 231 RESAMPLER_QUALITY_DEFAULT, 232 &er->provider, 233 &er->resampler); 234 if (rc != 0) { 235 er->resampler = NULL; 236 ALOGV("echo_reference_write() failure to create resampler %d", rc); 237 status = -ENODEV; 238 goto exit; 239 } 240 } 241 // er->wr_src_buf and er->wr_frames_in are used by getNexBuffer() called by the 242 // resampler to get new frames 243 if (er->rd_channel_count != er->wr_channel_count) { 244 er->wr_src_buf = er->wr_buf; 245 } else { 246 er->wr_src_buf = buffer->raw; 247 } 248 er->wr_frames_in = buffer->frame_count; 249 // inFrames is always more than we need here to get frames remaining from previous runs 250 // inFrames is updated by resample() with the number of frames produced 251 ALOGV("echo_reference_write() ReSampling(%d, %d)", 252 er->wr_sampling_rate, er->rd_sampling_rate); 253 er->resampler->resample_from_provider(er->resampler, 254 (int16_t *)er->wr_buf, &inFrames); 255 ALOGV_IF(er->wr_frames_in != 0, 256 "echo_reference_write() er->wr_frames_in not 0 (%d) after resampler", 257 er->wr_frames_in); 258 } 259 srcBuf = er->wr_buf; 260 } else { 261 inFrames = buffer->frame_count; 262 srcBuf = buffer->raw; 263 } 264 265 if (er->frames_in + inFrames > er->buf_size) { 266 ALOGV("echo_reference_write() increasing buffer size from %zu to %zu", 267 er->buf_size, er->frames_in + inFrames); 268 er->buf_size = er->frames_in + inFrames; 269 er->buffer = realloc(er->buffer, er->buf_size * er->rd_frame_size); 270 } 271 memcpy((char *)er->buffer + er->frames_in * er->rd_frame_size, 272 srcBuf, 273 inFrames * er->rd_frame_size); 274 er->frames_in += inFrames; 275 276 ALOGV("echo_reference_write() frames written:[%zu], frames total:[%zu] buffer size:[%zu]\n" 277 " er->wr_render_time:[%d].[%d], er->playback_delay:[%" PRId32 "]", 278 inFrames, er->frames_in, er->buf_size, 279 (int)er->wr_render_time.tv_sec, (int)er->wr_render_time.tv_nsec, er->playback_delay); 280 281 pthread_cond_signal(&er->cond); 282exit: 283 pthread_mutex_unlock(&er->lock); 284 ALOGV("echo_reference_write() END"); 285 return status; 286} 287 288// delay jump threshold to update ref buffer: 6 samples at 8kHz in nsecs 289#define MIN_DELAY_DELTA_NS (375000*2) 290// number of consecutive delta with same sign between expected and actual delay before adjusting 291// the buffer 292#define MIN_DELTA_NUM 4 293 294 295static int echo_reference_read(struct echo_reference_itfe *echo_reference, 296 struct echo_reference_buffer *buffer) 297{ 298 struct echo_reference *er = (struct echo_reference *)echo_reference; 299 300 if (er == NULL) { 301 return -EINVAL; 302 } 303 304 pthread_mutex_lock(&er->lock); 305 306 if (buffer == NULL) { 307 ALOGV("echo_reference_read() stop read"); 308 er->state &= ~ECHOREF_READING; 309 goto exit; 310 } 311 312 ALOGV("echo_reference_read() START, delayCapture:[%" PRId32 "], " 313 "er->frames_in:[%zu],buffer->frame_count:[%zu]", 314 buffer->delay_ns, er->frames_in, buffer->frame_count); 315 316 if ((er->state & ECHOREF_READING) == 0) { 317 ALOGV("echo_reference_read() start read"); 318 echo_reference_reset_l(er); 319 er->state |= ECHOREF_READING; 320 } 321 322 if ((er->state & ECHOREF_WRITING) == 0) { 323 memset(buffer->raw, 0, er->rd_frame_size * buffer->frame_count); 324 buffer->delay_ns = 0; 325 goto exit; 326 } 327 328// ALOGV("echo_reference_read() %d frames", buffer->frame_count); 329 330 // allow some time for new frames to arrive if not enough frames are ready for read 331 if (er->frames_in < buffer->frame_count) { 332 uint32_t timeoutMs = (uint32_t)((1000 * buffer->frame_count) / er->rd_sampling_rate / 2); 333 struct timespec ts = {0, 0}; 334 335 clock_gettime(CLOCK_REALTIME, &ts); 336 337 ts.tv_sec += timeoutMs/1000; 338 ts.tv_nsec += (timeoutMs%1000) * 1000000; 339 if (ts.tv_nsec >= 1000000000) { 340 ts.tv_nsec -= 1000000000; 341 ts.tv_sec += 1; 342 } 343 344 pthread_cond_timedwait(&er->cond, &er->lock, &ts); 345 346 ALOGV_IF((er->frames_in < buffer->frame_count), 347 "echo_reference_read() waited %d ms but still not enough frames"\ 348 " er->frames_in: %d, buffer->frame_count = %d", 349 timeoutMs, er->frames_in, buffer->frame_count); 350 } 351 352 int64_t timeDiff; 353 struct timespec tmp; 354 355 if ((er->wr_render_time.tv_sec == 0 && er->wr_render_time.tv_nsec == 0) || 356 (buffer->time_stamp.tv_sec == 0 && buffer->time_stamp.tv_nsec == 0)) { 357 ALOGV("echo_reference_read(): NEW:timestamp is zero---------setting timeDiff = 0, "\ 358 "not updating delay this time"); 359 timeDiff = 0; 360 } else { 361 if (buffer->time_stamp.tv_nsec < er->wr_render_time.tv_nsec) { 362 tmp.tv_sec = buffer->time_stamp.tv_sec - er->wr_render_time.tv_sec - 1; 363 tmp.tv_nsec = 1000000000 + buffer->time_stamp.tv_nsec - er->wr_render_time.tv_nsec; 364 } else { 365 tmp.tv_sec = buffer->time_stamp.tv_sec - er->wr_render_time.tv_sec; 366 tmp.tv_nsec = buffer->time_stamp.tv_nsec - er->wr_render_time.tv_nsec; 367 } 368 timeDiff = (((int64_t)tmp.tv_sec * 1000000000 + tmp.tv_nsec)); 369 370 int64_t expectedDelayNs = er->playback_delay + buffer->delay_ns - timeDiff; 371 372 if (er->resampler != NULL) { 373 // Resampler already compensates part of the delay 374 int32_t rsmp_delay = er->resampler->delay_ns(er->resampler); 375 expectedDelayNs -= rsmp_delay; 376 } 377 378 ALOGV("echo_reference_read(): expectedDelayNs[%" PRId64 "] = " 379 "er->playback_delay[%" PRId32 "] + delayCapture[%" PRId32 380 "] - timeDiff[%" PRId64 "]", 381 expectedDelayNs, er->playback_delay, buffer->delay_ns, timeDiff); 382 383 if (expectedDelayNs > 0) { 384 int64_t delayNs = ((int64_t)er->frames_in * 1000000000) / er->rd_sampling_rate; 385 386 int64_t deltaNs = delayNs - expectedDelayNs; 387 388 ALOGV("echo_reference_read(): EchoPathDelayDeviation between reference and DMA [%" 389 PRId64 "]", deltaNs); 390 if (llabs(deltaNs) >= MIN_DELAY_DELTA_NS) { 391 // smooth the variation and update the reference buffer only 392 // if a deviation in the same direction is observed for more than MIN_DELTA_NUM 393 // consecutive reads. 394 int16_t delay_sign = (deltaNs >= 0) ? 1 : -1; 395 if (delay_sign == er->prev_delta_sign) { 396 er->delta_count++; 397 } else { 398 er->delta_count = 1; 399 } 400 er->prev_delta_sign = delay_sign; 401 402 if (er->delta_count > MIN_DELTA_NUM) { 403 size_t previousFrameIn = er->frames_in; 404 er->frames_in = (size_t)((expectedDelayNs * er->rd_sampling_rate)/1000000000); 405 int offset = er->frames_in - previousFrameIn; 406 407 ALOGV("echo_reference_read(): deltaNs ENOUGH and %s: " 408 "er->frames_in: %zu, previousFrameIn = %zu", 409 delay_sign ? "positive" : "negative", er->frames_in, previousFrameIn); 410 411 if (deltaNs < 0) { 412 // Less data available in the reference buffer than expected 413 if (er->frames_in > er->buf_size) { 414 er->buf_size = er->frames_in; 415 er->buffer = realloc(er->buffer, er->buf_size * er->rd_frame_size); 416 ALOGV("echo_reference_read(): increasing buffer size to %zu", 417 er->buf_size); 418 } 419 420 if (offset > 0) { 421 memset((char *)er->buffer + previousFrameIn * er->rd_frame_size, 422 0, offset * er->rd_frame_size); 423 ALOGV("echo_reference_read(): pushing ref buffer by [%d]", offset); 424 } 425 } else { 426 // More data available in the reference buffer than expected 427 offset = -offset; 428 if (offset > 0) { 429 memcpy(er->buffer, (char *)er->buffer + (offset * er->rd_frame_size), 430 er->frames_in * er->rd_frame_size); 431 ALOGV("echo_reference_read(): shifting ref buffer by [%zu]", 432 er->frames_in); 433 } 434 } 435 } 436 } else { 437 er->delta_count = 0; 438 er->prev_delta_sign = 0; 439 ALOGV("echo_reference_read(): Constant EchoPathDelay - difference " 440 "between reference and DMA %" PRId64, deltaNs); 441 } 442 } else { 443 ALOGV("echo_reference_read(): NEGATIVE expectedDelayNs[%" PRId64 444 "] = er->playback_delay[%" PRId32 "] + delayCapture[%" PRId32 445 "] - timeDiff[%" PRId64 "]", 446 expectedDelayNs, er->playback_delay, buffer->delay_ns, timeDiff); 447 } 448 } 449 450 if (er->frames_in < buffer->frame_count) { 451 if (buffer->frame_count > er->buf_size) { 452 er->buf_size = buffer->frame_count; 453 er->buffer = realloc(er->buffer, er->buf_size * er->rd_frame_size); 454 ALOGV("echo_reference_read(): increasing buffer size to %zu", er->buf_size); 455 } 456 // filling up the reference buffer with 0s to match the expected delay. 457 memset((char *)er->buffer + er->frames_in * er->rd_frame_size, 458 0, (buffer->frame_count - er->frames_in) * er->rd_frame_size); 459 er->frames_in = buffer->frame_count; 460 } 461 462 memcpy(buffer->raw, 463 (char *)er->buffer, 464 buffer->frame_count * er->rd_frame_size); 465 466 er->frames_in -= buffer->frame_count; 467 memcpy(er->buffer, 468 (char *)er->buffer + buffer->frame_count * er->rd_frame_size, 469 er->frames_in * er->rd_frame_size); 470 471 // As the reference buffer is now time aligned to the microphone signal there is a zero delay 472 buffer->delay_ns = 0; 473 474 ALOGV("echo_reference_read() END %zu frames, total frames in %zu", 475 buffer->frame_count, er->frames_in); 476 477 pthread_cond_signal(&er->cond); 478 479exit: 480 pthread_mutex_unlock(&er->lock); 481 return 0; 482} 483 484 485int create_echo_reference(audio_format_t rdFormat, 486 uint32_t rdChannelCount, 487 uint32_t rdSamplingRate, 488 audio_format_t wrFormat, 489 uint32_t wrChannelCount, 490 uint32_t wrSamplingRate, 491 struct echo_reference_itfe **echo_reference) 492{ 493 struct echo_reference *er; 494 495 ALOGV("create_echo_reference()"); 496 497 if (echo_reference == NULL) { 498 return -EINVAL; 499 } 500 501 *echo_reference = NULL; 502 503 if (rdFormat != AUDIO_FORMAT_PCM_16_BIT || 504 rdFormat != wrFormat) { 505 ALOGW("create_echo_reference bad format rd %d, wr %d", rdFormat, wrFormat); 506 return -EINVAL; 507 } 508 if ((rdChannelCount != 1 && rdChannelCount != 2) || 509 wrChannelCount != 2) { 510 ALOGW("create_echo_reference bad channel count rd %d, wr %d", rdChannelCount, 511 wrChannelCount); 512 return -EINVAL; 513 } 514 515 er = (struct echo_reference *)calloc(1, sizeof(struct echo_reference)); 516 517 er->itfe.read = echo_reference_read; 518 er->itfe.write = echo_reference_write; 519 520 er->state = ECHOREF_IDLE; 521 er->rd_format = rdFormat; 522 er->rd_channel_count = rdChannelCount; 523 er->rd_sampling_rate = rdSamplingRate; 524 er->wr_format = wrFormat; 525 er->wr_channel_count = wrChannelCount; 526 er->wr_sampling_rate = wrSamplingRate; 527 er->rd_frame_size = audio_bytes_per_sample(rdFormat) * rdChannelCount; 528 er->wr_frame_size = audio_bytes_per_sample(wrFormat) * wrChannelCount; 529 *echo_reference = &er->itfe; 530 return 0; 531} 532 533void release_echo_reference(struct echo_reference_itfe *echo_reference) { 534 struct echo_reference *er = (struct echo_reference *)echo_reference; 535 536 if (er == NULL) { 537 return; 538 } 539 540 ALOGV("EchoReference dstor"); 541 echo_reference_reset_l(er); 542 if (er->resampler != NULL) { 543 release_resampler(er->resampler); 544 } 545 free(er); 546} 547 548