DXR is a code search and navigation tool aimed at making sense of large projects. It supports full-text and regex searches as well as structural queries.

Implementation

Mercurial (d38398e5144e)

VCS Links

MediaDecoder

PlayState

ResourceCallback

ResourceSizes

Macros

Line Code
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 162 163 164 165 166 167 168 169 170 171 172 173 174 175 176 177 178 179 180 181 182 183 184 185 186 187 188 189 190 191 192 193 194 195 196 197 198 199 200 201 202 203 204 205 206 207 208 209 210 211 212 213 214 215 216 217 218 219 220 221 222 223 224 225 226 227 228 229 230 231 232 233 234 235 236 237 238 239 240 241 242 243 244 245 246 247 248 249 250 251 252 253 254 255 256 257 258 259 260 261 262 263 264 265 266 267 268 269 270 271 272 273 274 275 276 277 278 279 280 281 282 283 284 285 286 287 288 289 290 291 292 293 294 295 296 297 298 299 300 301 302 303 304 305 306 307 308 309 310 311 312 313 314 315 316 317 318 319 320 321 322 323 324 325 326 327 328 329 330 331 332 333 334 335 336 337 338 339 340 341 342 343 344 345 346 347 348 349 350 351 352 353 354 355 356 357 358 359 360 361 362 363 364 365 366 367 368 369 370 371 372 373 374 375 376 377 378 379 380 381 382 383 384 385 386 387 388 389 390 391 392 393 394 395 396 397 398 399 400 401 402 403 404 405 406 407 408 409 410 411 412 413 414 415 416 417 418 419 420 421 422 423 424 425 426 427 428 429 430 431 432 433 434 435 436 437 438 439 440 441 442 443 444 445 446 447 448 449 450 451 452 453 454 455 456 457 458 459 460 461 462 463 464 465 466 467 468 469 470 471 472 473 474 475 476 477 478 479 480 481 482 483 484 485 486 487 488 489 490 491 492 493 494 495 496 497 498 499 500 501 502 503 504 505 506 507 508 509 510 511 512 513 514 515 516 517 518 519 520 521 522 523 524 525 526 527 528 529 530 531 532 533 534 535 536 537 538 539 540 541 542 543 544 545 546 547 548 549 550 551 552 553 554 555 556 557 558 559 560 561 562 563 564 565 566 567 568 569 570 571 572 573 574 575 576 577 578 579 580 581 582 583 584 585 586 587 588 589 590 591 592 593 594 595 596 597 598 599 600 601 602 603 604 605 606 607 608 609 610 611 612 613 614 615 616 617 618 619 620 621 622 623 624 625 626 627 628 629 630 631 632 633 634 635 636 637 638 639 640 641 642 643 644 645 646 647 648 649 650 651 652 653 654 655 656 657 658 659 660 661 662 663 664 665 666 667 668 669 670 671 672 673 674 675 676 677 678 679 680 681 682 683 684 685 686 687 688 689 690 691 692 693 694 695 696 697 698 699 700 701 702 703 704 705 706 707 708 709 710 711 712 713 714 715 716 717 718 719 720 721 722 723 724 725 726 727 728 729 730 731 732 733 734 735 736 737 738 739 740 741 742 743 744 745 746 747 748 749 750 751 752 753 754 755 756 757 758 759 760 761 762 763 764 765 766 767 768 769 770 771 772 773 774 775 776 777 778 779 780 781 782 783 784 785 786 787 788 789 790 791 792 793 794 795 796 797 798 799 800 801 802 803 804 805 806 807 808 809 810 811 812 813 814 815 816 817 818 819 820 821 822 823 824 825 826 827 828 829 830 831 832 833 834 835 836 837 838 839 840 841 842 843 844 845 846 847 848 849 850 851 852 853 854 855 856 857 858 859 860 861 862 863 864 865 866 867 868 869 870 871 872 873 874 875 876 877 878 879 880 881 882 883 884 885 886 887 888 889 890 891 892 893 894
/* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
/* vim:set ts=2 sw=2 sts=2 et cindent: */
/* This Source Code Form is subject to the terms of the Mozilla Public
 * License, v. 2.0. If a copy of the MPL was not distributed with this
 * file, You can obtain one at http://mozilla.org/MPL/2.0/. */

#if !defined(MediaDecoder_h_)
#define MediaDecoder_h_

#include "mozilla/Atomics.h"
#include "mozilla/CDMProxy.h"
#include "mozilla/MozPromise.h"
#include "mozilla/ReentrantMonitor.h"
#include "mozilla/StateMirroring.h"
#include "mozilla/StateWatching.h"

#include "mozilla/dom/AudioChannelBinding.h"

#include "necko-config.h"
#include "nsAutoPtr.h"
#include "nsCOMPtr.h"
#include "nsIObserver.h"
#include "nsISupports.h"
#include "nsITimer.h"

#include "AbstractMediaDecoder.h"
#include "DecoderDoctorDiagnostics.h"
#include "MediaDecoderOwner.h"
#include "MediaEventSource.h"
#include "MediaMetadataManager.h"
#include "MediaResource.h"
#include "MediaResourceCallback.h"
#include "MediaStatistics.h"
#include "MediaStreamGraph.h"
#include "TimeUnits.h"
#include "SeekTarget.h"

class nsIStreamListener;
class nsIPrincipal;

namespace mozilla {

namespace dom {
class Promise;
class HTMLMediaElement;
}

class AbstractThread;
class VideoFrameContainer;
class MediaDecoderStateMachine;

enum class MediaEventType : int8_t;

// GetCurrentTime is defined in winbase.h as zero argument macro forwarding to
// GetTickCount() and conflicts with MediaDecoder::GetCurrentTime implementation.
#ifdef GetCurrentTime
#undef GetCurrentTime
#endif

class MediaDecoder : public AbstractMediaDecoder
{
public:
  // Used to register with MediaResource to receive notifications which will
  // be forwarded to MediaDecoder.
  class ResourceCallback : public MediaResourceCallback
  {
    // Throttle calls to MediaDecoder::NotifyDataArrived()
    // to be at most once per 500ms.
    static const uint32_t sDelay = 500;

  public:
    explicit ResourceCallback(AbstractThread* aMainThread);
    // Start to receive notifications from ResourceCallback.
    void Connect(MediaDecoder* aDecoder);
    // Called upon shutdown to stop receiving notifications.
    void Disconnect();

  private:
    /* MediaResourceCallback functions */
    MediaDecoderOwner* GetMediaOwner() const override;
    void SetInfinite(bool aInfinite) override;
    void NotifyNetworkError() override;
    void NotifyDecodeError() override;
    void NotifyDataArrived() override;
    void NotifyBytesDownloaded() override;
    void NotifyDataEnded(nsresult aStatus) override;
    void NotifyPrincipalChanged() override;
    void NotifySuspendedStatusChanged() override;
    void NotifyBytesConsumed(int64_t aBytes, int64_t aOffset) override;

    static void TimerCallback(nsITimer* aTimer, void* aClosure);

    // The decoder to send notifications. Main-thread only.
    MediaDecoder* mDecoder = nullptr;
    nsCOMPtr<nsITimer> mTimer;
    bool mTimerArmed = false;
    const RefPtr<AbstractThread> mAbstractMainThread;
  };

  typedef MozPromise<bool /* aIgnored */, bool /* aIgnored */,
                     /* IsExclusive = */ true>
    SeekPromise;

  NS_DECL_THREADSAFE_ISUPPORTS

  // Enumeration for the valid play states (see mPlayState)
  enum PlayState
  {
    PLAY_STATE_START,
    PLAY_STATE_LOADING,
    PLAY_STATE_PAUSED,
    PLAY_STATE_PLAYING,
    PLAY_STATE_ENDED,
    PLAY_STATE_SHUTDOWN
  };

  // Must be called exactly once, on the main thread, during startup.
  static void InitStatics();

  explicit MediaDecoder(MediaDecoderOwner* aOwner);

  // Return a callback object used to register with MediaResource to receive
  // notifications.
  MediaResourceCallback* GetResourceCallback() const;

  // Create a new decoder of the same type as this one.
  // Subclasses must implement this.
  virtual MediaDecoder* Clone(MediaDecoderOwner* aOwner) = 0;
  // Create a new state machine to run this decoder.
  // Subclasses must implement this.
  virtual MediaDecoderStateMachine* CreateStateMachine() = 0;

  // Cleanup internal data structures. Must be called on the main
  // thread by the owning object before that object disposes of this object.
  virtual void Shutdown();

  // Notified by the shutdown manager that XPCOM shutdown has begun.
  // The decoder should notify its owner to drop the reference to the decoder
  // to prevent further calls into the decoder.
  void NotifyXPCOMShutdown();

  // Start downloading the media. Decode the downloaded data up to the
  // point of the first frame of data.
  // This is called at most once per decoder, after Init().
  virtual nsresult Load(nsIStreamListener** aListener);

  // Called in |Load| to open mResource.
  nsresult OpenResource(nsIStreamListener** aStreamListener);

  // Called if the media file encounters a network error.
  void NetworkError();

  // Get the current MediaResource being used. Its URI will be returned
  // by currentSrc. Returns what was passed to Load(), if Load() has been called.
  // Note: The MediaResource is refcounted, but it outlives the MediaDecoder,
  // so it's OK to use the reference returned by this function without
  // refcounting, *unless* you need to store and use the reference after the
  // MediaDecoder has been destroyed. You might need to do this if you're
  // wrapping the MediaResource in some kind of byte stream interface to be
  // passed to a platform decoder.
  MediaResource* GetResource() const final override
  {
    return mResource;
  }
  void SetResource(MediaResource* aResource)
  {
    MOZ_ASSERT(NS_IsMainThread());
    mResource = aResource;
  }

  // Return the principal of the current URI being played or downloaded.
  virtual already_AddRefed<nsIPrincipal> GetCurrentPrincipal();

  // Return the time position in the video stream being
  // played measured in seconds.
  virtual double GetCurrentTime();

  // Seek to the time position in (seconds) from the start of the video.
  // If aDoFastSeek is true, we'll seek to the sync point/keyframe preceeding
  // the seek target.
  virtual nsresult Seek(double aTime, SeekTarget::Type aSeekType,
                        dom::Promise* aPromise = nullptr);

  // Initialize state machine and schedule it.
  nsresult InitializeStateMachine();

  // Start playback of a video. 'Load' must have previously been
  // called.
  virtual nsresult Play();

  // Notify activity of the decoder owner is changed.
  virtual void NotifyOwnerActivityChanged(bool aIsVisible);

  // Pause video playback.
  virtual void Pause();
  // Adjust the speed of the playback, optionally with pitch correction,
  virtual void SetVolume(double aVolume);

  virtual void SetPlaybackRate(double aPlaybackRate);
  void SetPreservesPitch(bool aPreservesPitch);

  // Directs the decoder to not preroll extra samples until the media is
  // played. This reduces the memory overhead of media elements that may
  // not be played. Note that seeking also doesn't cause us start prerolling.
  void SetMinimizePrerollUntilPlaybackStarts();

  bool GetMinimizePreroll() const { return mMinimizePreroll; }

  // All MediaStream-related data is protected by mReentrantMonitor.
  // We have at most one DecodedStreamData per MediaDecoder. Its stream
  // is used as the input for each ProcessedMediaStream created by calls to
  // captureStream(UntilEnded). Seeking creates a new source stream, as does
  // replaying after the input as ended. In the latter case, the new source is
  // not connected to streams created by captureStreamUntilEnded.

  // Add an output stream. All decoder output will be sent to the stream.
  // The stream is initially blocked. The decoder is responsible for unblocking
  // it while it is playing back.
  virtual void AddOutputStream(ProcessedMediaStream* aStream,
                               bool aFinishWhenEnded);
  // Remove an output stream added with AddOutputStream.
  virtual void RemoveOutputStream(MediaStream* aStream);

  // Return the duration of the video in seconds.
  virtual double GetDuration();

  // Return true if the stream is infinite (see SetInfinite).
  bool IsInfinite() const;

  // Called by MediaResource when some data has been received.
  // Call on the main thread only.
  virtual void NotifyBytesDownloaded();

  // Called as data arrives on the stream and is read into the cache.  Called
  // on the main thread only.
  void NotifyDataArrived();

  // Return true if we are currently seeking in the media resource.
  // Call on the main thread only.
  bool IsSeeking() const;

  // Return true if the decoder has reached the end of playback.
  bool IsEnded() const;

  // True if we are playing a MediaSource object.
  virtual bool IsMSE() const { return false; }

  // Return true if the MediaDecoderOwner's error attribute is not null.
  // Must be called before Shutdown().
  bool OwnerHasError() const;

  already_AddRefed<GMPCrashHelper> GetCrashHelper() override;

protected:
  // Updates the media duration. This is called while the media is being
  // played, calls before the media has reached loaded metadata are ignored.
  // The duration is assumed to be an estimate, and so a degree of
  // instability is expected; if the incoming duration is not significantly
  // different from the existing duration, the change request is ignored.
  // If the incoming duration is significantly different, the duration is
  // changed, this causes a durationchanged event to fire to the media
  // element.
  void UpdateEstimatedMediaDuration(int64_t aDuration) override;

public:
  // Returns true if this media supports random seeking. False for example with
  // chained ogg files.
  bool IsMediaSeekable();
  // Returns true if seeking is supported on a transport level (e.g. the server
  // supports range requests, we are playing a file, etc.).
  bool IsTransportSeekable();

  // Return the time ranges that can be seeked into.
  virtual media::TimeIntervals GetSeekable();

  // Set the end time of the media resource. When playback reaches
  // this point the media pauses. aTime is in seconds.
  virtual void SetFragmentEndTime(double aTime);

  // Invalidate the frame.
  void Invalidate();
  void InvalidateWithFlags(uint32_t aFlags);

  // Suspend any media downloads that are in progress. Called by the
  // media element when it is sent to the bfcache, or when we need
  // to throttle the download. Call on the main thread only. This can
  // be called multiple times, there's an internal "suspend count".
  virtual void Suspend();

  // Resume any media downloads that have been suspended. Called by the
  // media element when it is restored from the bfcache, or when we need
  // to stop throttling the download. Call on the main thread only.
  // The download will only actually resume once as many Resume calls
  // have been made as Suspend calls.
  virtual void Resume();

  // Moves any existing channel loads into or out of background. Background
  // loads don't block the load event. This is called when we stop or restart
  // delaying the load event. This also determines whether any new loads
  // initiated (for example to seek) will be in the background.  This calls
  // SetLoadInBackground() on mResource.
  void SetLoadInBackground(bool aLoadInBackground);

  MediaDecoderStateMachine* GetStateMachine() const;
  void SetStateMachine(MediaDecoderStateMachine* aStateMachine);

  // Constructs the time ranges representing what segments of the media
  // are buffered and playable.
  virtual media::TimeIntervals GetBuffered();

  // Returns the size, in bytes, of the heap memory used by the currently
  // queued decoded video and audio data.
  size_t SizeOfVideoQueue();
  size_t SizeOfAudioQueue();

  // Helper struct for accumulating resource sizes that need to be measured
  // asynchronously. Once all references are dropped the callback will be
  // invoked.
  struct ResourceSizes
  {
    typedef MozPromise<size_t, size_t, true> SizeOfPromise;
    NS_INLINE_DECL_THREADSAFE_REFCOUNTING(ResourceSizes)
    explicit ResourceSizes(MallocSizeOf aMallocSizeOf)
      : mMallocSizeOf(aMallocSizeOf)
      , mByteSize(0)
      , mCallback()
    {
    }

    mozilla::MallocSizeOf mMallocSizeOf;
    mozilla::Atomic<size_t> mByteSize;

    RefPtr<SizeOfPromise> Promise()
    {
      return mCallback.Ensure(__func__);
    }

private:
    ~ResourceSizes()
    {
      mCallback.ResolveIfExists(mByteSize, __func__);
    }

    MozPromiseHolder<SizeOfPromise> mCallback;
  };

  virtual void AddSizeOfResources(ResourceSizes* aSizes);

  VideoFrameContainer* GetVideoFrameContainer() final override
  {
    return mVideoFrameContainer;
  }
  layers::ImageContainer* GetImageContainer() override;

  // Fire timeupdate events if needed according to the time constraints
  // outlined in the specification.
  void FireTimeUpdate();

  // Something has changed that could affect the computed playback rate,
  // so recompute it. The monitor must be held.
  virtual void UpdatePlaybackRate();

  // The actual playback rate computation. The monitor must be held.
  void ComputePlaybackRate();

  // Returns true if we can play the entire media through without stopping
  // to buffer, given the current download and playback rates.
  virtual bool CanPlayThrough();

  void SetAudioChannel(dom::AudioChannel aChannel) { mAudioChannel = aChannel; }
  dom::AudioChannel GetAudioChannel() { return mAudioChannel; }

  // Called from HTMLMediaElement when owner document activity changes
  virtual void SetElementVisibility(bool aIsVisible);

  // Force override the visible state to hidden.
  // Called from HTMLMediaElement when testing of video decode suspend from mochitests.
  void SetForcedHidden(bool aForcedHidden);

  /******
   * The following methods must only be called on the main
   * thread.
   ******/

  // Change to a new play state. This updates the mState variable and
  // notifies any thread blocking on this object's monitor of the
  // change. Call on the main thread only.
  virtual void ChangeState(PlayState aState);

  // Called from MetadataLoaded(). Creates audio tracks and adds them to its
  // owner's audio track list, and implies to video tracks respectively.
  // Call on the main thread only.
  void ConstructMediaTracks();

  // Removes all audio tracks and video tracks that are previously added into
  // the track list. Call on the main thread only.
  void RemoveMediaTracks();

  // Called when the video has completed playing.
  // Call on the main thread only.
  void PlaybackEnded();

  void OnSeekRejected();
  void OnSeekResolved();

  void SeekingChanged()
  {
    // Stop updating the bytes downloaded for progress notifications when
    // seeking to prevent wild changes to the progress notification.
    MOZ_ASSERT(NS_IsMainThread());
    mIgnoreProgressData = mLogicallySeeking;
  }

  // Seeking has started. Inform the element on the main thread.
  void SeekingStarted();

  void UpdateLogicalPositionInternal();
  void UpdateLogicalPosition()
  {
    MOZ_ASSERT(NS_IsMainThread());
    MOZ_DIAGNOSTIC_ASSERT(!IsShutdown());
    // Per spec, offical position remains stable during pause and seek.
    if (mPlayState == PLAY_STATE_PAUSED || IsSeeking()) {
      return;
    }
    UpdateLogicalPositionInternal();
  }

  // Find the end of the cached data starting at the current decoder
  // position.
  int64_t GetDownloadPosition();

  // Notifies the element that decoding has failed.
  void DecodeError(const MediaResult& aError);

  // Indicate whether the media is same-origin with the element.
  void UpdateSameOriginStatus(bool aSameOrigin);

  MediaDecoderOwner* GetOwner() const override;

  AbstractThread* AbstractMainThread() const final override
  {
    return mAbstractMainThread;
  }

  typedef MozPromise<RefPtr<CDMProxy>, bool /* aIgnored */,
                     /* IsExclusive = */ true>
    CDMProxyPromise;

  // Resolved when a CDMProxy is available and the capabilities are known or
  // rejected when this decoder is about to shut down.
  RefPtr<CDMProxyPromise> RequestCDMProxy() const;

  void SetCDMProxy(CDMProxy* aProxy);

  void EnsureTelemetryReported();

  static bool IsOggEnabled();
  static bool IsOpusEnabled();
  static bool IsWaveEnabled();
  static bool IsWebMEnabled();

#ifdef MOZ_ANDROID_OMX
  static bool IsAndroidMediaPluginEnabled();
#endif

#ifdef MOZ_WMF
  static bool IsWMFEnabled();
#endif

  // Return statistics. This is used for progress events and other things.
  // This can be called from any thread. It's only a snapshot of the
  // current state, since other threads might be changing the state
  // at any time.
  MediaStatistics GetStatistics();

  // Return the frame decode/paint related statistics.
  FrameStatistics& GetFrameStatistics() { return *mFrameStats; }

  // Increments the parsed and decoded frame counters by the passed in counts.
  // Can be called on any thread.
  virtual void NotifyDecodedFrames(const FrameStatisticsData& aStats) override
  {
    GetFrameStatistics().NotifyDecodedFrames(aStats);
  }

  void UpdateReadyState()
  {
    MOZ_ASSERT(NS_IsMainThread());
    MOZ_DIAGNOSTIC_ASSERT(!IsShutdown());
    GetOwner()->UpdateReadyState();
  }

  virtual MediaDecoderOwner::NextFrameStatus NextFrameStatus()
  {
    return mNextFrameStatus;
  }
  virtual MediaDecoderOwner::NextFrameStatus NextFrameBufferedStatus();

  // Returns a string describing the state of the media player internal
  // data. Used for debugging purposes.
  virtual void GetMozDebugReaderData(nsACString& aString) { }

  virtual void DumpDebugInfo();

  using DebugInfoPromise = MozPromise<nsCString, bool, true>;
  RefPtr<DebugInfoPromise> RequestDebugInfo();

protected:
  virtual ~MediaDecoder();

  // Called when the first audio and/or video from the media file has been loaded
  // by the state machine. Call on the main thread only.
  virtual void FirstFrameLoaded(nsAutoPtr<MediaInfo> aInfo,
                                MediaDecoderEventVisibility aEventVisibility);

  void SetStateMachineParameters();

  bool IsShutdown() const;

  // Called by the state machine to notify the decoder that the duration
  // has changed.
  void DurationChanged();

  // State-watching manager.
  WatchManager<MediaDecoder> mWatchManager;

  // Used by the ogg decoder to watch mStateMachineIsShutdown.
  virtual void ShutdownBitChanged() {}

  double ExplicitDuration() { return mExplicitDuration.Ref().ref(); }

  void SetExplicitDuration(double aValue)
  {
    MOZ_DIAGNOSTIC_ASSERT(!IsShutdown());
    mExplicitDuration.Set(Some(aValue));

    // We Invoke DurationChanged explicitly, rather than using a watcher, so
    // that it takes effect immediately, rather than at the end of the current task.
    DurationChanged();
  }

  /******
   * The following members should be accessed with the decoder lock held.
   ******/

  // The logical playback position of the media resource in units of
  // seconds. This corresponds to the "official position" in HTML5. Note that
  // we need to store this as a double, rather than an int64_t (like
  // mCurrentPosition), so that |v.currentTime = foo; v.currentTime == foo|
  // returns true without being affected by rounding errors.
  double mLogicalPosition;

  // The current playback position of the underlying playback infrastructure.
  // This corresponds to the "current position" in HTML5.
  // We allow omx subclasses to substitute an alternative current position for
  // usage with the audio offload player.
  virtual int64_t CurrentPosition() { return mCurrentPosition; }

  // Official duration of the media resource as observed by script.
  double mDuration;

  /******
   * The following member variables can be accessed from any thread.
   ******/

  // Media data resource.
  RefPtr<MediaResource> mResource;

  // Amount of buffered data ahead of current time required to consider that
  // the next frame is available.
  // An arbitrary value of 250ms is used.
  static const int DEFAULT_NEXT_FRAME_AVAILABLE_BUFFERED = 250000;

private:
  nsCString GetDebugInfo();

  // Called when the metadata from the media file has been loaded by the
  // state machine. Call on the main thread only.
  void MetadataLoaded(nsAutoPtr<MediaInfo> aInfo,
                      nsAutoPtr<MetadataTags> aTags,
                      MediaDecoderEventVisibility aEventVisibility);

  MediaEventSource<void>*
  DataArrivedEvent() override { return &mDataArrivedEvent; }

  MediaEventSource<RefPtr<layers::KnowsCompositor>>*
  CompositorUpdatedEvent() override { return &mCompositorUpdatedEvent; }

  void OnPlaybackEvent(MediaEventType aEvent);
  void OnPlaybackErrorEvent(const MediaResult& aError);

  void OnDecoderDoctorEvent(DecoderDoctorEvent aEvent);

  void OnMediaNotSeekable()
  {
    mMediaSeekable = false;
  }

  void FinishShutdown();

  void ConnectMirrors(MediaDecoderStateMachine* aObject);
  void DisconnectMirrors();

  MediaEventProducer<void> mDataArrivedEvent;
  MediaEventProducer<RefPtr<layers::KnowsCompositor>> mCompositorUpdatedEvent;

  // The state machine object for handling the decoding. It is safe to
  // call methods of this object from other threads. Its internal data
  // is synchronised on a monitor. The lifetime of this object is
  // after mPlayState is LOADING and before mPlayState is SHUTDOWN. It
  // is safe to access it during this period.
  //
  // Explicitly prievate to force access via accessors.
  RefPtr<MediaDecoderStateMachine> mDecoderStateMachine;

  RefPtr<ResourceCallback> mResourceCallback;

  MozPromiseHolder<CDMProxyPromise> mCDMProxyPromiseHolder;
  RefPtr<CDMProxyPromise> mCDMProxyPromise;

protected:
  // The promise resolving/rejection is queued as a "micro-task" which will be
  // handled immediately after the current JS task and before any pending JS
  // tasks.
  // At the time we are going to resolve/reject a promise, the "seeking" event
  // task should already be queued but might yet be processed, so we queue one
  // more task to file the promise resolving/rejection micro-tasks
  // asynchronously to make sure that the micro-tasks are processed after the
  // "seeking" event task.
  void AsyncResolveSeekDOMPromiseIfExists();
  void AsyncRejectSeekDOMPromiseIfExists();
  void DiscardOngoingSeekIfExists();
  virtual void CallSeek(const SeekTarget& aTarget, dom::Promise* aPromise);

  MozPromiseRequestHolder<SeekPromise> mSeekRequest;
  RefPtr<dom::Promise> mSeekDOMPromise;

  // True when seeking or otherwise moving the play position around in
  // such a manner that progress event data is inaccurate. This is set
  // during seek and duration operations to prevent the progress indicator
  // from jumping around. Read/Write on the main thread only.
  bool mIgnoreProgressData;

  // True if the stream is infinite (e.g. a webradio).
  bool mInfiniteStream;

  // Ensures our media stream has been pinned.
  void PinForSeek();

  // Ensures our media stream has been unpinned.
  void UnpinForSeek();

  const char* PlayStateStr();

  void OnMetadataUpdate(TimedMetadata&& aMetadata);

  // This should only ever be accessed from the main thread.
  // It is set in the constructor and cleared in Shutdown when the element goes
  // away. The decoder does not add a reference the element.
  MediaDecoderOwner* mOwner;

  // The AbstractThread from mOwner.
  const RefPtr<AbstractThread> mAbstractMainThread;

  // Counters related to decode and presentation of frames.
  const RefPtr<FrameStatistics> mFrameStats;

  RefPtr<VideoFrameContainer> mVideoFrameContainer;

  // Data needed to estimate playback data rate. The timeline used for
  // this estimate is "decode time" (where the "current time" is the
  // time of the last decoded video frame).
  RefPtr<MediaChannelStatistics> mPlaybackStatistics;

  // True when our media stream has been pinned. We pin the stream
  // while seeking.
  bool mPinnedForSeek;

  // Be assigned from media element during the initialization and pass to
  // AudioStream Class.
  dom::AudioChannel mAudioChannel;

  // True if the decoder has been directed to minimize its preroll before
  // playback starts. After the first time playback starts, we don't attempt
  // to minimize preroll, as we assume the user is likely to keep playing,
  // or play the media again.
  bool mMinimizePreroll;

  // True if audio tracks and video tracks are constructed and added into the
  // track list, false if all tracks are removed from the track list.
  bool mMediaTracksConstructed;

  // True if we've already fired metadataloaded.
  bool mFiredMetadataLoaded;

  // True if the media is seekable (i.e. supports random access).
  bool mMediaSeekable = true;

  // True if the media is only seekable within its buffered ranges
  // like WebMs with no cues.
  bool mMediaSeekableOnlyInBufferedRanges = false;

  // Stores media info, including info of audio tracks and video tracks, should
  // only be accessed from main thread.
  nsAutoPtr<MediaInfo> mInfo;

  // Tracks the visiblity status from HTMLMediaElement
  bool mElementVisible;

  // If true, forces the decoder to be considered hidden.
  bool mForcedHidden;

  // A listener to receive metadata updates from MDSM.
  MediaEventListener mTimedMetadataListener;

  MediaEventListener mMetadataLoadedListener;
  MediaEventListener mFirstFrameLoadedListener;

  MediaEventListener mOnPlaybackEvent;
  MediaEventListener mOnPlaybackErrorEvent;
  MediaEventListener mOnDecoderDoctorEvent;
  MediaEventListener mOnMediaNotSeekable;

protected:
  // Whether the state machine is shut down.
  Mirror<bool> mStateMachineIsShutdown;

  // Buffered range, mirrored from the reader.
  Mirror<media::TimeIntervals> mBuffered;

  // NextFrameStatus, mirrored from the state machine.
  Mirror<MediaDecoderOwner::NextFrameStatus> mNextFrameStatus;

  // NB: Don't use mCurrentPosition directly, but rather CurrentPosition().
  Mirror<int64_t> mCurrentPosition;

  // Duration of the media resource according to the state machine.
  Mirror<media::NullableTimeUnit> mStateMachineDuration;

  // Current playback position in the stream. This is (approximately)
  // where we're up to playing back the stream. This is not adjusted
  // during decoder seek operations, but it's updated at the end when we
  // start playing back again.
  Mirror<int64_t> mPlaybackPosition;

  // Used to distinguish whether the audio is producing sound.
  Mirror<bool> mIsAudioDataAudible;

  // Volume of playback.  0.0 = muted. 1.0 = full volume.
  Canonical<double> mVolume;

  // PlaybackRate and pitch preservation status we should start at.
  double mPlaybackRate = 1;

  Canonical<bool> mPreservesPitch;

  // Media duration according to the demuxer's current estimate.
  // Note that it's quite bizarre for this to live on the main thread - it would
  // make much more sense for this to be owned by the demuxer's task queue. But
  // currently this is only every changed in NotifyDataArrived, which runs on
  // the main thread. That will need to be cleaned up at some point.
  Canonical<media::NullableTimeUnit> mEstimatedDuration;

  // Media duration set explicitly by JS. At present, this is only ever present
  // for MSE.
  Canonical<Maybe<double>> mExplicitDuration;

  // Set to one of the valid play states.
  // This can only be changed on the main thread while holding the decoder
  // monitor. Thus, it can be safely read while holding the decoder monitor
  // OR on the main thread.
  Canonical<PlayState> mPlayState;

  // This can only be changed on the main thread while holding the decoder
  // monitor. Thus, it can be safely read while holding the decoder monitor
  // OR on the main thread.
  Canonical<PlayState> mNextState;

  // True if the decoder is seeking.
  Canonical<bool> mLogicallySeeking;

  // True if the media is same-origin with the element. Data can only be
  // passed to MediaStreams when this is true.
  Canonical<bool> mSameOriginMedia;

  // An identifier for the principal of the media. Used to track when
  // main-thread induced principal changes get reflected on MSG thread.
  Canonical<PrincipalHandle> mMediaPrincipalHandle;

  // Estimate of the current playback rate (bytes/second).
  Canonical<double> mPlaybackBytesPerSecond;

  // True if mPlaybackBytesPerSecond is a reliable estimate.
  Canonical<bool> mPlaybackRateReliable;

  // Current decoding position in the stream. This is where the decoder
  // is up to consuming the stream. This is not adjusted during decoder
  // seek operations, but it's updated at the end when we start playing
  // back again.
  Canonical<int64_t> mDecoderPosition;

  // True if the decoder is visible.
  Canonical<bool> mIsVisible;

public:
  AbstractCanonical<media::NullableTimeUnit>* CanonicalDurationOrNull() override;
  AbstractCanonical<double>* CanonicalVolume() { return &mVolume; }
  AbstractCanonical<bool>* CanonicalPreservesPitch()
  {
    return &mPreservesPitch;
  }
  AbstractCanonical<media::NullableTimeUnit>* CanonicalEstimatedDuration()
  {
    return &mEstimatedDuration;
  }
  AbstractCanonical<Maybe<double>>* CanonicalExplicitDuration()
  {
    return &mExplicitDuration;
  }
  AbstractCanonical<PlayState>* CanonicalPlayState() { return &mPlayState; }
  AbstractCanonical<PlayState>* CanonicalNextPlayState() { return &mNextState; }
  AbstractCanonical<bool>* CanonicalLogicallySeeking()
  {
    return &mLogicallySeeking;
  }
  AbstractCanonical<bool>* CanonicalSameOriginMedia()
  {
    return &mSameOriginMedia;
  }
  AbstractCanonical<PrincipalHandle>* CanonicalMediaPrincipalHandle()
  {
    return &mMediaPrincipalHandle;
  }
  AbstractCanonical<double>* CanonicalPlaybackBytesPerSecond()
  {
    return &mPlaybackBytesPerSecond;
  }
  AbstractCanonical<bool>* CanonicalPlaybackRateReliable()
  {
    return &mPlaybackRateReliable;
  }
  AbstractCanonical<int64_t>* CanonicalDecoderPosition()
  {
    return &mDecoderPosition;
  }
  AbstractCanonical<bool>* CanonicalIsVisible() { return &mIsVisible; }

private:
  // Notify owner when the audible state changed
  void NotifyAudibleStateChanged();

  /* Functions called by ResourceCallback */

  // A media stream is assumed to be infinite if the metadata doesn't
  // contain the duration, and range requests are not supported, and
  // no headers give a hint of a possible duration (Content-Length,
  // Content-Duration, and variants), and we cannot seek in the media
  // stream to determine the duration.
  //
  // When the media stream ends, we can know the duration, thus the stream is
  // no longer considered to be infinite.
  void SetInfinite(bool aInfinite);

  // Called by MediaResource when the principal of the resource has
  // changed. Called on main thread only.
  void NotifyPrincipalChanged();

  // Called by MediaResource when the "cache suspended" status changes.
  // If MediaResource::IsSuspendedByCache returns true, then the decoder
  // should stop buffering or otherwise waiting for download progress and
  // start consuming data, if possible, because the cache is full.
  void NotifySuspendedStatusChanged();

  // Called by the MediaResource to keep track of the number of bytes read
  // from the resource. Called on the main by an event runner dispatched
  // by the MediaResource read functions.
  void NotifyBytesConsumed(int64_t aBytes, int64_t aOffset);

  // Called by nsChannelToPipeListener or MediaResource when the
  // download has ended. Called on the main thread only. aStatus is
  // the result from OnStopRequest.
  void NotifyDownloadEnded(nsresult aStatus);

  bool mTelemetryReported;

  // Used to debug how mOwner becomes a dangling pointer in bug 1326294.
  bool mIsMediaElement;
  WeakPtr<dom::HTMLMediaElement> mElement;
};

} // namespace mozilla

#endif