src/media/filters/audio_renderer_impl.cc

   1 // Copyright (c) 2012 The Chromium Authors. All rights reserved.
   2 // Use of this source code is governed by a BSD-style license that can be
   3 // found in the LICENSE file.
   4
   5 #include "media/filters/audio_renderer_impl.h"
   6
   7 #include <math.h>
   8
   9 #include <algorithm>
  10
  11 #include "base/bind.h"
  12 #include "base/callback.h"
  13 #include "base/callback_helpers.h"
  14 #include "base/logging.h"
  15 #include "base/metrics/histogram.h"
  16 #include "base/single_thread_task_runner.h"
  17 #include "media/base/audio_buffer.h"
  18 #include "media/base/audio_splicer.h"
  19 #include "media/base/bind_to_current_loop.h"
  20 #include "media/base/demuxer_stream.h"
  21 #include "media/filters/decrypting_demuxer_stream.h"
  22
  23 namespace media {
  24
  25 namespace {
  26
  27 enum AudioRendererEvent {
  28   INITIALIZED,
  29   RENDER_ERROR,
  30   MAX_EVENTS
  31 };
  32
  33 void HistogramRendererEvent(AudioRendererEvent event) {
  34   UMA_HISTOGRAM_ENUMERATION("Media.AudioRendererEvents", event, MAX_EVENTS);
  35 }
  36
  37 }  // namespace
  38
  39 AudioRendererImpl::AudioRendererImpl(
  40     const scoped_refptr<base::SingleThreadTaskRunner>& task_runner,
  41     media::AudioRendererSink* sink,
  42     ScopedVector<AudioDecoder> decoders,
  43     const SetDecryptorReadyCB& set_decryptor_ready_cb)
  44     : task_runner_(task_runner),
  45       weak_factory_(this),
  46       sink_(sink),
  47       decoder_selector_(new AudioDecoderSelector(
  48           task_runner, decoders.Pass(), set_decryptor_ready_cb)),
  49       now_cb_(base::Bind(&base::TimeTicks::Now)),
  50       state_(kUninitialized),
  51       sink_playing_(false),
  52       pending_read_(false),
  53       received_end_of_stream_(false),
  54       rendered_end_of_stream_(false),
  55       audio_time_buffered_(kNoTimestamp()),
  56       current_time_(kNoTimestamp()),
  57       underflow_disabled_(false),
  58       preroll_aborted_(false) {
  59 }
  60
  61 AudioRendererImpl::~AudioRendererImpl() {
  62   // Stop() should have been called and |algorithm_| should have been destroyed.
  63   DCHECK(state_ == kUninitialized || state_ == kStopped);
  64   DCHECK(!algorithm_.get());
  65 }
  66
  67 void AudioRendererImpl::Play(const base::Closure& callback) {
  68   DCHECK(task_runner_->BelongsToCurrentThread());
  69
  70   base::AutoLock auto_lock(lock_);
  71   DCHECK_EQ(state_, kPaused);
  72   ChangeState_Locked(kPlaying);
  73   callback.Run();
  74   earliest_end_time_ = now_cb_.Run();
  75
  76   if (algorithm_->playback_rate() != 0)
  77     DoPlay_Locked();
  78   else
  79     DCHECK(!sink_playing_);
  80 }
  81
  82 void AudioRendererImpl::DoPlay_Locked() {
  83   DCHECK(task_runner_->BelongsToCurrentThread());
  84   lock_.AssertAcquired();
  85   earliest_end_time_ = now_cb_.Run();
  86
  87   if ((state_ == kPlaying || state_ == kRebuffering || state_ == kUnderflow) &&
  88       !sink_playing_) {
  89     {
  90       base::AutoUnlock auto_unlock(lock_);
  91       sink_->Play();
  92     }
  93
  94     sink_playing_ = true;
  95   }
  96 }
  97
  98 void AudioRendererImpl::Pause(const base::Closure& callback) {
  99   DCHECK(task_runner_->BelongsToCurrentThread());
 100
 101   base::AutoLock auto_lock(lock_);
 102   DCHECK(state_ == kPlaying || state_ == kUnderflow ||
 103          state_ == kRebuffering) << "state_ == " << state_;
 104   ChangeState_Locked(kPaused);
 105
 106   DoPause_Locked();
 107
 108   callback.Run();
 109 }
 110
 111 void AudioRendererImpl::DoPause_Locked() {
 112   DCHECK(task_runner_->BelongsToCurrentThread());
 113   lock_.AssertAcquired();
 114
 115   if (sink_playing_) {
 116     {
 117       base::AutoUnlock auto_unlock(lock_);
 118       sink_->Pause();
 119     }
 120     sink_playing_ = false;
 121   }
 122 }
 123
 124 void AudioRendererImpl::Flush(const base::Closure& callback) {
 125   DCHECK(task_runner_->BelongsToCurrentThread());
 126
 127   base::AutoLock auto_lock(lock_);
 128   DCHECK_EQ(state_, kPaused);
 129   DCHECK(flush_cb_.is_null());
 130
 131   flush_cb_ = callback;
 132
 133   if (pending_read_) {
 134     ChangeState_Locked(kFlushing);
 135     return;
 136   }
 137
 138   DoFlush_Locked();
 139 }
 140
 141 void AudioRendererImpl::DoFlush_Locked() {
 142   DCHECK(task_runner_->BelongsToCurrentThread());
 143   lock_.AssertAcquired();
 144
 145   DCHECK(!pending_read_);
 146   DCHECK_EQ(state_, kPaused);
 147
 148   if (decrypting_demuxer_stream_) {
 149     decrypting_demuxer_stream_->Reset(
 150         base::Bind(&AudioRendererImpl::ResetDecoder, weak_this_));
 151     return;
 152   }
 153
 154   ResetDecoder();
 155 }
 156
 157 void AudioRendererImpl::ResetDecoder() {
 158   DCHECK(task_runner_->BelongsToCurrentThread());
 159   decoder_->Reset(base::Bind(&AudioRendererImpl::ResetDecoderDone, weak_this_));
 160 }
 161
 162 void AudioRendererImpl::ResetDecoderDone() {
 163   DCHECK(task_runner_->BelongsToCurrentThread());
 164   {
 165     base::AutoLock auto_lock(lock_);
 166     if (state_ == kStopped)
 167       return;
 168
 169     DCHECK_EQ(state_, kPaused);
 170     DCHECK(!flush_cb_.is_null());
 171
 172     audio_time_buffered_ = kNoTimestamp();
 173     current_time_ = kNoTimestamp();
 174     received_end_of_stream_ = false;
 175     rendered_end_of_stream_ = false;
 176     preroll_aborted_ = false;
 177
 178     earliest_end_time_ = now_cb_.Run();
 179     splicer_->Reset();
 180     algorithm_->FlushBuffers();
 181   }
 182   base::ResetAndReturn(&flush_cb_).Run();
 183 }
 184
 185 void AudioRendererImpl::Stop(const base::Closure& callback) {
 186   DCHECK(task_runner_->BelongsToCurrentThread());
 187   DCHECK(!callback.is_null());
 188   DCHECK(stop_cb_.is_null());
 189
 190   stop_cb_ = callback;
 191
 192   // TODO(scherkus): Consider invalidating |weak_factory_| and replacing
 193   // task-running guards that check |state_| with DCHECK().
 194
 195   {
 196     base::AutoLock auto_lock(lock_);
 197     if (state_ == kInitializing) {
 198       decoder_selector_->Abort();
 199       return;
 200     }
 201
 202     if (state_ == kStopped) {
 203       task_runner_->PostTask(FROM_HERE, base::ResetAndReturn(&stop_cb_));
 204       return;
 205     }
 206
 207     ChangeState_Locked(kStopped);
 208     algorithm_.reset();
 209     underflow_cb_.Reset();
 210     time_cb_.Reset();
 211     flush_cb_.Reset();
 212   }
 213
 214   if (sink_) {
 215     sink_->Stop();
 216     sink_ = NULL;
 217   }
 218
 219   if (decrypting_demuxer_stream_) {
 220     decrypting_demuxer_stream_->Stop(
 221         base::Bind(&AudioRendererImpl::StopDecoder, weak_this_));
 222     return;
 223   }
 224
 225   StopDecoder();
 226 }
 227
 228 void AudioRendererImpl::StopDecoder() {
 229   DCHECK(task_runner_->BelongsToCurrentThread());
 230   DCHECK(!stop_cb_.is_null());
 231
 232   if (decoder_) {
 233     decoder_->Stop(base::ResetAndReturn(&stop_cb_));
 234     return;
 235   }
 236
 237   task_runner_->PostTask(FROM_HERE, base::ResetAndReturn(&stop_cb_));
 238 }
 239
 240 void AudioRendererImpl::Preroll(base::TimeDelta time,
 241                                 const PipelineStatusCB& cb) {
 242   DCHECK(task_runner_->BelongsToCurrentThread());
 243
 244   base::AutoLock auto_lock(lock_);
 245   DCHECK(!sink_playing_);
 246   DCHECK_EQ(state_, kPaused);
 247   DCHECK(!pending_read_) << "Pending read must complete before seeking";
 248   DCHECK(preroll_cb_.is_null());
 249
 250   ChangeState_Locked(kPrerolling);
 251   preroll_cb_ = cb;
 252   preroll_timestamp_ = time;
 253
 254   AttemptRead_Locked();
 255 }
 256
 257 void AudioRendererImpl::Initialize(DemuxerStream* stream,
 258                                    const PipelineStatusCB& init_cb,
 259                                    const StatisticsCB& statistics_cb,
 260                                    const base::Closure& underflow_cb,
 261                                    const TimeCB& time_cb,
 262                                    const base::Closure& ended_cb,
 263                                    const base::Closure& disabled_cb,
 264                                    const PipelineStatusCB& error_cb) {
 265   DCHECK(task_runner_->BelongsToCurrentThread());
 266   DCHECK(stream);
 267   DCHECK_EQ(stream->type(), DemuxerStream::AUDIO);
 268   DCHECK(!init_cb.is_null());
 269   DCHECK(!statistics_cb.is_null());
 270   DCHECK(!underflow_cb.is_null());
 271   DCHECK(!time_cb.is_null());
 272   DCHECK(!ended_cb.is_null());
 273   DCHECK(!disabled_cb.is_null());
 274   DCHECK(!error_cb.is_null());
 275   DCHECK_EQ(kUninitialized, state_);
 276   DCHECK(sink_);
 277
 278   state_ = kInitializing;
 279
 280   weak_this_ = weak_factory_.GetWeakPtr();
 281   init_cb_ = init_cb;
 282   statistics_cb_ = statistics_cb;
 283   underflow_cb_ = underflow_cb;
 284   time_cb_ = time_cb;
 285   ended_cb_ = ended_cb;
 286   disabled_cb_ = disabled_cb;
 287   error_cb_ = error_cb;
 288
 289   decoder_selector_->SelectDecoder(
 290       stream,
 291       statistics_cb,
 292       base::Bind(&AudioRendererImpl::OnDecoderSelected, weak_this_));
 293 }
 294
 295 void AudioRendererImpl::OnDecoderSelected(
 296     scoped_ptr<AudioDecoder> decoder,
 297     scoped_ptr<DecryptingDemuxerStream> decrypting_demuxer_stream) {
 298   DCHECK(task_runner_->BelongsToCurrentThread());
 299
 300   scoped_ptr<AudioDecoderSelector> deleter(decoder_selector_.Pass());
 301   decoder_ = decoder.Pass();
 302
 303   if (!decoder_ || !stop_cb_.is_null()) {
 304     {
 305       base::AutoLock auto_lock(lock_);
 306       ChangeState_Locked(kUninitialized);
 307     }
 308     // Stop() called during initialization.
 309     if (!stop_cb_.is_null()) {
 310       base::ResetAndReturn(&init_cb_).Run(PIPELINE_ERROR_ABORT);
 311       Stop(base::ResetAndReturn(&stop_cb_));
 312     } else {
 313       base::ResetAndReturn(&init_cb_).Run(DECODER_ERROR_NOT_SUPPORTED);
 314     }
 315     return;
 316   }
 317
 318   base::AutoLock auto_lock(lock_);
 319   decrypting_demuxer_stream_ = decrypting_demuxer_stream.Pass();
 320
 321   int sample_rate = decoder_->samples_per_second();
 322
 323   // The actual buffer size is controlled via the size of the AudioBus
 324   // provided to Render(), so just choose something reasonable here for looks.
 325   int buffer_size = decoder_->samples_per_second() / 100;
 326   audio_parameters_ = AudioParameters(
 327       AudioParameters::AUDIO_PCM_LOW_LATENCY, decoder_->channel_layout(),
 328       sample_rate, decoder_->bits_per_channel(), buffer_size);
 329   if (!audio_parameters_.IsValid()) {
 330     ChangeState_Locked(kUninitialized);
 331     base::ResetAndReturn(&init_cb_).Run(PIPELINE_ERROR_INITIALIZATION_FAILED);
 332     return;
 333   }
 334
 335   splicer_.reset(new AudioSplicer(sample_rate));
 336
 337   // We're all good! Continue initializing the rest of the audio renderer
 338   // based on the decoder format.
 339   algorithm_.reset(new AudioRendererAlgorithm());
 340   algorithm_->Initialize(0, audio_parameters_);
 341
 342   ChangeState_Locked(kPaused);
 343
 344   HistogramRendererEvent(INITIALIZED);
 345
 346   {
 347     base::AutoUnlock auto_unlock(lock_);
 348     sink_->Initialize(audio_parameters_, weak_this_.get());
 349     sink_->Start();
 350
 351     // Some sinks play on start...
 352     sink_->Pause();
 353   }
 354
 355   DCHECK(!sink_playing_);
 356
 357   base::ResetAndReturn(&init_cb_).Run(PIPELINE_OK);
 358 }
 359
 360 void AudioRendererImpl::ResumeAfterUnderflow() {
 361   DCHECK(task_runner_->BelongsToCurrentThread());
 362   base::AutoLock auto_lock(lock_);
 363   if (state_ == kUnderflow) {
 364     // The "!preroll_aborted_" is a hack. If preroll is aborted, then we
 365     // shouldn't even reach the kUnderflow state to begin with. But for now
 366     // we're just making sure that the audio buffer capacity (i.e. the
 367     // number of bytes that need to be buffered for preroll to complete)
 368     // does not increase due to an aborted preroll.
 369     // TODO(vrk): Fix this bug correctly! (crbug.com/151352)
 370     if (!preroll_aborted_)
 371       algorithm_->IncreaseQueueCapacity();
 372
 373     ChangeState_Locked(kRebuffering);
 374   }
 375 }
 376
 377 void AudioRendererImpl::SetVolume(float volume) {
 378   DCHECK(task_runner_->BelongsToCurrentThread());
 379   DCHECK(sink_);
 380   sink_->SetVolume(volume);
 381 }
 382
 383 void AudioRendererImpl::DecodedAudioReady(
 384     AudioDecoder::Status status,
 385     const scoped_refptr<AudioBuffer>& buffer) {
 386   DVLOG(1) << __FUNCTION__ << "(" << status << ")";
 387   DCHECK(task_runner_->BelongsToCurrentThread());
 388
 389   base::AutoLock auto_lock(lock_);
 390   DCHECK(state_ != kUninitialized);
 391
 392   CHECK(pending_read_);
 393   pending_read_ = false;
 394
 395   if (status == AudioDecoder::kAborted) {
 396     HandleAbortedReadOrDecodeError(false);
 397     return;
 398   }
 399
 400   if (status == AudioDecoder::kDecodeError) {
 401     HandleAbortedReadOrDecodeError(true);
 402     return;
 403   }
 404
 405   DCHECK_EQ(status, AudioDecoder::kOk);
 406   DCHECK(buffer.get());
 407
 408   if (state_ == kFlushing) {
 409     ChangeState_Locked(kPaused);
 410     DoFlush_Locked();
 411     return;
 412   }
 413
 414   if (!splicer_->AddInput(buffer)) {
 415     HandleAbortedReadOrDecodeError(true);
 416     return;
 417   }
 418
 419   if (!splicer_->HasNextBuffer()) {
 420     AttemptRead_Locked();
 421     return;
 422   }
 423
 424   bool need_another_buffer = false;
 425   while (splicer_->HasNextBuffer())
 426     need_another_buffer = HandleSplicerBuffer(splicer_->GetNextBuffer());
 427
 428   if (!need_another_buffer && !CanRead_Locked())
 429     return;
 430
 431   AttemptRead_Locked();
 432 }
 433
 434 bool AudioRendererImpl::HandleSplicerBuffer(
 435     const scoped_refptr<AudioBuffer>& buffer) {
 436   if (buffer->end_of_stream()) {
 437     received_end_of_stream_ = true;
 438
 439     // Transition to kPlaying if we are currently handling an underflow since
 440     // no more data will be arriving.
 441     if (state_ == kUnderflow || state_ == kRebuffering)
 442       ChangeState_Locked(kPlaying);
 443   } else {
 444     if (state_ == kPrerolling) {
 445       if (IsBeforePrerollTime(buffer))
 446         return true;
 447
 448       // Trim off any additional time before the preroll timestamp.
 449       const base::TimeDelta trim_time =
 450           preroll_timestamp_ - buffer->timestamp();
 451       if (trim_time > base::TimeDelta()) {
 452         buffer->TrimStart(buffer->frame_count() *
 453                           (static_cast<double>(trim_time.InMicroseconds()) /
 454                            buffer->duration().InMicroseconds()));
 455       }
 456       // If the entire buffer was trimmed, request a new one.
 457       if (!buffer->frame_count())
 458         return true;
 459     }
 460
 461     if (state_ != kUninitialized && state_ != kStopped)
 462       algorithm_->EnqueueBuffer(buffer);
 463   }
 464
 465   switch (state_) {
 466     case kUninitialized:
 467     case kInitializing:
 468     case kFlushing:
 469       NOTREACHED();
 470       return false;
 471
 472     case kPaused:
 473       DCHECK(!pending_read_);
 474       return false;
 475
 476     case kPrerolling:
 477       if (!buffer->end_of_stream() && !algorithm_->IsQueueFull())
 478         return true;
 479       ChangeState_Locked(kPaused);
 480       base::ResetAndReturn(&preroll_cb_).Run(PIPELINE_OK);
 481       return false;
 482
 483     case kPlaying:
 484     case kUnderflow:
 485       return false;
 486
 487     case kRebuffering:
 488       if (!algorithm_->IsQueueFull())
 489         return true;
 490       ChangeState_Locked(kPlaying);
 491       return false;
 492
 493     case kStopped:
 494       return false;
 495   }
 496   return false;
 497 }
 498
 499 void AudioRendererImpl::AttemptRead() {
 500   base::AutoLock auto_lock(lock_);
 501   AttemptRead_Locked();
 502 }
 503
 504 void AudioRendererImpl::AttemptRead_Locked() {
 505   DCHECK(task_runner_->BelongsToCurrentThread());
 506   lock_.AssertAcquired();
 507
 508   if (!CanRead_Locked())
 509     return;
 510
 511   pending_read_ = true;
 512   decoder_->Read(base::Bind(&AudioRendererImpl::DecodedAudioReady, weak_this_));
 513 }
 514
 515 bool AudioRendererImpl::CanRead_Locked() {
 516   lock_.AssertAcquired();
 517
 518   switch (state_) {
 519     case kUninitialized:
 520     case kInitializing:
 521     case kPaused:
 522     case kFlushing:
 523     case kStopped:
 524       return false;
 525
 526     case kPrerolling:
 527     case kPlaying:
 528     case kUnderflow:
 529     case kRebuffering:
 530       break;
 531   }
 532
 533   return !pending_read_ && !received_end_of_stream_ &&
 534       !algorithm_->IsQueueFull();
 535 }
 536
 537 void AudioRendererImpl::SetPlaybackRate(float playback_rate) {
 538   DVLOG(1) << __FUNCTION__ << "(" << playback_rate << ")";
 539   DCHECK(task_runner_->BelongsToCurrentThread());
 540   DCHECK_GE(playback_rate, 0);
 541   DCHECK(sink_);
 542
 543   base::AutoLock auto_lock(lock_);
 544
 545   // We have two cases here:
 546   // Play: current_playback_rate == 0 && playback_rate != 0
 547   // Pause: current_playback_rate != 0 && playback_rate == 0
 548   float current_playback_rate = algorithm_->playback_rate();
 549   if (current_playback_rate == 0 && playback_rate != 0)
 550     DoPlay_Locked();
 551   else if (current_playback_rate != 0 && playback_rate == 0)
 552     DoPause_Locked();
 553
 554   algorithm_->SetPlaybackRate(playback_rate);
 555 }
 556
 557 bool AudioRendererImpl::IsBeforePrerollTime(
 558     const scoped_refptr<AudioBuffer>& buffer) {
 559   DCHECK_EQ(state_, kPrerolling);
 560   return buffer && !buffer->end_of_stream() &&
 561          (buffer->timestamp() + buffer->duration()) < preroll_timestamp_;
 562 }
 563
 564 int AudioRendererImpl::Render(AudioBus* audio_bus,
 565                               int audio_delay_milliseconds) {
 566   const int requested_frames = audio_bus->frames();
 567   base::TimeDelta current_time = kNoTimestamp();
 568   base::TimeDelta max_time = kNoTimestamp();
 569   base::TimeDelta playback_delay = base::TimeDelta::FromMilliseconds(
 570       audio_delay_milliseconds);
 571
 572   int frames_written = 0;
 573   base::Closure underflow_cb;
 574   {
 575     base::AutoLock auto_lock(lock_);
 576
 577     // Ensure Stop() hasn't destroyed our |algorithm_| on the pipeline thread.
 578     if (!algorithm_)
 579       return 0;
 580
 581     float playback_rate = algorithm_->playback_rate();
 582     if (playback_rate == 0)
 583       return 0;
 584
 585     // Mute audio by returning 0 when not playing.
 586     if (state_ != kPlaying)
 587       return 0;
 588
 589     // We use the following conditions to determine end of playback:
 590     //   1) Algorithm can not fill the audio callback buffer
 591     //   2) We received an end of stream buffer
 592     //   3) We haven't already signalled that we've ended
 593     //   4) Our estimated earliest end time has expired
 594     //
 595     // TODO(enal): we should replace (4) with a check that the browser has no
 596     // more audio data or at least use a delayed callback.
 597     //
 598     // We use the following conditions to determine underflow:
 599     //   1) Algorithm can not fill the audio callback buffer
 600     //   2) We have NOT received an end of stream buffer
 601     //   3) We are in the kPlaying state
 602     //
 603     // Otherwise the buffer has data we can send to the device.
 604     frames_written = algorithm_->FillBuffer(audio_bus, requested_frames);
 605     if (frames_written == 0) {
 606       const base::TimeTicks now = now_cb_.Run();
 607
 608       if (received_end_of_stream_ && !rendered_end_of_stream_ &&
 609           now >= earliest_end_time_) {
 610         rendered_end_of_stream_ = true;
 611         ended_cb_.Run();
 612       } else if (!received_end_of_stream_ && state_ == kPlaying &&
 613                  !underflow_disabled_) {
 614         ChangeState_Locked(kUnderflow);
 615         underflow_cb = underflow_cb_;
 616       } else {
 617         // We can't write any data this cycle. For example, we may have
 618         // sent all available data to the audio device while not reaching
 619         // |earliest_end_time_|.
 620       }
 621     }
 622
 623     if (CanRead_Locked()) {
 624       task_runner_->PostTask(FROM_HERE, base::Bind(
 625           &AudioRendererImpl::AttemptRead, weak_this_));
 626     }
 627
 628     // The |audio_time_buffered_| is the ending timestamp of the last frame
 629     // buffered at the audio device. |playback_delay| is the amount of time
 630     // buffered at the audio device. The current time can be computed by their
 631     // difference.
 632     if (audio_time_buffered_ != kNoTimestamp()) {
 633       // Adjust the delay according to playback rate.
 634       base::TimeDelta adjusted_playback_delay =
 635           base::TimeDelta::FromMicroseconds(ceil(
 636               playback_delay.InMicroseconds() * playback_rate));
 637
 638       base::TimeDelta previous_time = current_time_;
 639       current_time_ = audio_time_buffered_ - adjusted_playback_delay;
 640
 641       // Time can change in one of two ways:
 642       //   1) The time of the audio data at the audio device changed, or
 643       //   2) The playback delay value has changed
 644       //
 645       // We only want to set |current_time| (and thus execute |time_cb_|) if
 646       // time has progressed and we haven't signaled end of stream yet.
 647       //
 648       // Why? The current latency of the system results in getting the last call
 649       // to FillBuffer() later than we'd like, which delays firing the 'ended'
 650       // event, which delays the looping/trigging performance of short sound
 651       // effects.
 652       //
 653       // TODO(scherkus): revisit this and switch back to relying on playback
 654       // delay after we've revamped our audio IPC subsystem.
 655       if (current_time_ > previous_time && !rendered_end_of_stream_) {
 656         current_time = current_time_;
 657       }
 658     }
 659
 660     // The call to FillBuffer() on |algorithm_| has increased the amount of
 661     // buffered audio data. Update the new amount of time buffered.
 662     max_time = algorithm_->GetTime();
 663     audio_time_buffered_ = max_time;
 664
 665     if (frames_written > 0) {
 666       UpdateEarliestEndTime_Locked(
 667           frames_written, playback_delay, now_cb_.Run());
 668     }
 669   }
 670
 671   if (current_time != kNoTimestamp() && max_time != kNoTimestamp())
 672     time_cb_.Run(current_time, max_time);
 673
 674   if (!underflow_cb.is_null())
 675     underflow_cb.Run();
 676
 677   DCHECK_LE(frames_written, requested_frames);
 678   return frames_written;
 679 }
 680
 681 void AudioRendererImpl::UpdateEarliestEndTime_Locked(
 682     int frames_filled, const base::TimeDelta& playback_delay,
 683     const base::TimeTicks& time_now) {
 684   DCHECK_GT(frames_filled, 0);
 685
 686   base::TimeDelta predicted_play_time = base::TimeDelta::FromMicroseconds(
 687       static_cast<float>(frames_filled) * base::Time::kMicrosecondsPerSecond /
 688       audio_parameters_.sample_rate());
 689
 690   lock_.AssertAcquired();
 691   earliest_end_time_ = std::max(
 692       earliest_end_time_, time_now + playback_delay + predicted_play_time);
 693 }
 694
 695 void AudioRendererImpl::OnRenderError() {
 696   HistogramRendererEvent(RENDER_ERROR);
 697   disabled_cb_.Run();
 698 }
 699
 700 void AudioRendererImpl::DisableUnderflowForTesting() {
 701   underflow_disabled_ = true;
 702 }
 703
 704 void AudioRendererImpl::HandleAbortedReadOrDecodeError(bool is_decode_error) {
 705   lock_.AssertAcquired();
 706
 707   PipelineStatus status = is_decode_error ? PIPELINE_ERROR_DECODE : PIPELINE_OK;
 708   switch (state_) {
 709     case kUninitialized:
 710     case kInitializing:
 711       NOTREACHED();
 712       return;
 713     case kPaused:
 714       if (status != PIPELINE_OK)
 715         error_cb_.Run(status);
 716       return;
 717     case kFlushing:
 718       ChangeState_Locked(kPaused);
 719
 720       if (status == PIPELINE_OK) {
 721         DoFlush_Locked();
 722         return;
 723       }
 724
 725       error_cb_.Run(status);
 726       base::ResetAndReturn(&flush_cb_).Run();
 727       return;
 728     case kPrerolling:
 729       // This is a signal for abort if it's not an error.
 730       preroll_aborted_ = !is_decode_error;
 731       ChangeState_Locked(kPaused);
 732       base::ResetAndReturn(&preroll_cb_).Run(status);
 733       return;
 734     case kPlaying:
 735     case kUnderflow:
 736     case kRebuffering:
 737     case kStopped:
 738       if (status != PIPELINE_OK)
 739         error_cb_.Run(status);
 740       return;
 741   }
 742 }
 743
 744 void AudioRendererImpl::ChangeState_Locked(State new_state) {
 745   DVLOG(1) << __FUNCTION__ << " : " << state_ << " -> " << new_state;
 746   lock_.AssertAcquired();
 747   state_ = new_state;
 748 }
 749
 750 }  // namespace media