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/* 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 */
#include "DecoderDoctorDiagnostics.h"
#include "MediaDecoder.h"
#include "MediaDecoderOwner.h"
#include "MediaEventSource.h"
#include "MediaInfo.h"
#include "MediaMetadataManager.h"
#include "MediaPromiseDefs.h"
#include "ReaderProxy.h"
#include "VideoFrameContainer.h"
#include "mozilla/dom/MediaDebugInfoBinding.h"
#include "mozilla/Variant.h"
#include "nsISupportsImpl.h"
class AudioDeviceInfo;
namespace mozilla {
class AbstractThread;
class CDMProxy;
class FrameStatistics;
class MediaFormatReader;
class TaskQueue;
struct MediaPlaybackEvent {
enum EventType {
} mType;
using DataType = Variant<Nothing, int64_t>;
DataType mData;
MOZ_IMPLICIT MediaPlaybackEvent(EventType aType)
: mType(aType), mData(Nothing{}) {}
template <typename T>
MediaPlaybackEvent(EventType aType, T&& aArg)
: mType(aType), mData(std::forward<T>(aArg)) {}
enum class VideoDecodeMode : uint8_t { Normal, Suspend };
* The state machine class. This manages the decoding and seeking in the
* MediaDecoderReader on the decode task queue, and A/V sync on the shared
* state machine thread, and controls the audio "push" thread.
* All internal state is synchronised via the decoder monitor. State changes
* are propagated by scheduling the state machine to run another cycle on the
* shared state machine thread.
class MediaDecoderStateMachineBase {
using FirstFrameEventSourceExc =
MediaEventSourceExc<UniquePtr<MediaInfo>, MediaDecoderEventVisibility>;
using MetadataEventSourceExc =
MediaEventSourceExc<UniquePtr<MediaInfo>, UniquePtr<MetadataTags>,
using NextFrameStatus = MediaDecoderOwner::NextFrameStatus;
MediaDecoderStateMachineBase(MediaDecoder* aDecoder,
MediaFormatReader* aReader);
virtual nsresult Init(MediaDecoder* aDecoder);
RefPtr<ShutdownPromise> BeginShutdown();
// Seeks to the decoder to aTarget asynchronously.
RefPtr<MediaDecoder::SeekPromise> InvokeSeek(const SeekTarget& aTarget);
virtual size_t SizeOfVideoQueue() const = 0;
virtual size_t SizeOfAudioQueue() const = 0;
// Sets the video decode mode. Used by the suspend-video-decoder feature.
virtual void SetVideoDecodeMode(VideoDecodeMode aMode) = 0;
virtual RefPtr<GenericPromise> InvokeSetSink(
const RefPtr<AudioDeviceInfo>& aSink) = 0;
virtual void InvokeSuspendMediaSink() = 0;
virtual void InvokeResumeMediaSink() = 0;
virtual RefPtr<GenericPromise> RequestDebugInfo(
dom::MediaDecoderStateMachineDebugInfo& aInfo) = 0;
// Returns the state machine task queue.
TaskQueue* OwnerThread() const { return mTaskQueue; }
MetadataEventSourceExc& MetadataLoadedEvent() { return mMetadataLoadedEvent; }
FirstFrameEventSourceExc& FirstFrameLoadedEvent() {
return mFirstFrameLoadedEvent;
OnSecondaryVideoContainerInstalled() {
return mOnSecondaryVideoContainerInstalled;
TimedMetadataEventSource& TimedMetadataEvent() {
return mMetadataManager.TimedMetadataEvent();
MediaEventSource<MediaPlaybackEvent>& OnPlaybackEvent() {
return mOnPlaybackEvent;
MediaEventSource<MediaResult>& OnPlaybackErrorEvent() {
return mOnPlaybackErrorEvent;
MediaEventSource<DecoderDoctorEvent>& OnDecoderDoctorEvent() {
return mOnDecoderDoctorEvent;
MediaEventSource<NextFrameStatus>& OnNextFrameStatus() {
return mOnNextFrameStatus;
MediaEventProducer<VideoInfo, AudioInfo>& OnTrackInfoUpdatedEvent() {
return mReader->OnTrackInfoUpdatedEvent();
MediaEventSource<void>& OnMediaNotSeekable() const;
AbstractCanonical<media::NullableTimeUnit>* CanonicalDuration() {
return &mDuration;
AbstractCanonical<media::TimeUnit>* CanonicalCurrentPosition() {
return &mCurrentPosition;
AbstractCanonical<bool>* CanonicalIsAudioDataAudible() {
return &mIsAudioDataAudible;
AbstractCanonical<media::TimeIntervals>* CanonicalBuffered() const;
void DispatchSetFragmentEndTime(const media::TimeUnit& aEndTime);
void DispatchCanPlayThrough(bool aCanPlayThrough);
void DispatchIsLiveStream(bool aIsLiveStream);
void DispatchSetPlaybackRate(double aPlaybackRate);
virtual RefPtr<SetCDMPromise> SetCDMProxy(CDMProxy* aProxy);
virtual bool IsExternalStateMachine() const { return false; }
virtual ~MediaDecoderStateMachineBase() = default;
bool HasAudio() const { return mInfo.ref().HasAudio(); }
bool HasVideo() const { return mInfo.ref().HasVideo(); }
const MediaInfo& Info() const { return mInfo.ref(); }
virtual void SetPlaybackRate(double aPlaybackRate) = 0;
virtual void SetIsLiveStream(bool aIsLiveStream) = 0;
virtual void SetCanPlayThrough(bool aCanPlayThrough) = 0;
virtual void SetFragmentEndTime(const media::TimeUnit& aFragmentEndTime) = 0;
virtual void BufferedRangeUpdated() = 0;
virtual void VolumeChanged() = 0;
virtual void PreservesPitchChanged() = 0;
virtual void PlayStateChanged() = 0;
virtual void LoopingChanged() = 0;
virtual void UpdateSecondaryVideoContainer() = 0;
// Init tasks which should be done on the task queue.
virtual void InitializationTask(MediaDecoder* aDecoder);
virtual RefPtr<ShutdownPromise> Shutdown() = 0;
virtual RefPtr<MediaDecoder::SeekPromise> Seek(const SeekTarget& aTarget) = 0;
void DecodeError(const MediaResult& aError);
// Functions used by assertions to ensure we're calling things
// on the appropriate threads.
bool OnTaskQueue() const;
bool IsRequestingAudioData() const { return mAudioDataRequest.Exists(); }
bool IsRequestingVideoData() const { return mVideoDataRequest.Exists(); }
bool IsWaitingAudioData() const { return mAudioWaitRequest.Exists(); }
bool IsWaitingVideoData() const { return mVideoWaitRequest.Exists(); }
void* const mDecoderID;
const RefPtr<AbstractThread> mAbstractMainThread;
const RefPtr<FrameStatistics> mFrameStats;
const RefPtr<VideoFrameContainer> mVideoFrameContainer;
const RefPtr<TaskQueue> mTaskQueue;
const RefPtr<ReaderProxy> mReader;
mozilla::MediaMetadataManager mMetadataManager;
// Playback rate. 1.0 : normal speed, 0.5 : two times slower.
double mPlaybackRate;
// Event producers
MediaEventProducerExc<UniquePtr<MediaInfo>, UniquePtr<MetadataTags>,
MediaEventProducerExc<UniquePtr<MediaInfo>, MediaDecoderEventVisibility>
MediaEventProducer<MediaPlaybackEvent> mOnPlaybackEvent;
MediaEventProducer<MediaResult> mOnPlaybackErrorEvent;
MediaEventProducer<DecoderDoctorEvent> mOnDecoderDoctorEvent;
MediaEventProducer<NextFrameStatus> mOnNextFrameStatus;
// The buffered range. Mirrored from the decoder thread.
Mirror<media::TimeIntervals> mBuffered;
// The current play state, mirrored from the main thread.
Mirror<MediaDecoder::PlayState> mPlayState;
// Volume of playback. 0.0 = muted. 1.0 = full volume.
Mirror<double> mVolume;
// Pitch preservation for the playback rate.
Mirror<bool> mPreservesPitch;
// Whether to seek back to the start of the media resource
// upon reaching the end.
Mirror<bool> mLooping;
// Set if the decoder is sending video to a secondary container. While set we
// should not suspend the decoder.
Mirror<RefPtr<VideoFrameContainer>> mSecondaryVideoContainer;
// Duration of the media. This is guaranteed to be non-null after we finish
// decoding the first frame.
Canonical<media::NullableTimeUnit> mDuration;
// The time of the current frame, corresponding to the "current
// playback position" in HTML5. This is referenced from 0, which is the
// initial playback position.
Canonical<media::TimeUnit> mCurrentPosition;
// Used to distinguish whether the audio is producing sound.
Canonical<bool> mIsAudioDataAudible;
// Stores presentation info required for playback.
Maybe<MediaInfo> mInfo;
// True if the media is seekable (i.e. supports random access).
bool mMediaSeekable = true;
// True if the media is seekable only in buffered ranges.
bool mMediaSeekableOnlyInBufferedRanges = false;
// True if we've decoded first frames (thus having the start time) and
// notified the FirstFrameLoaded event. Note we can't initiate seek until the
// start time is known which happens when the first frames are decoded or we
// are playing an MSE stream (the start time is always assumed 0).
bool mSentFirstFrameLoadedEvent = false;
// True if we should not decode/preroll unnecessary samples, unless we're
// played. "Prerolling" in this context refers to when we decode and
// buffer decoded samples in advance of when they're needed for playback.
// This flag is set for preload=metadata media, and means we won't
// decode more than the first video frame and first block of audio samples
// for that media when we startup, or after a seek. When Play() is called,
// we reset this flag, as we assume the user is playing the media, so
// prerolling is appropriate then. This flag is used to reduce the overhead
// of prerolling samples for media elements that may not play, both
// memory and CPU overhead.
bool mMinimizePreroll;
// Only one of a given pair of ({Audio,Video}DataPromise, WaitForDataPromise)
// should exist at any given moment.
using AudioDataPromise = MediaFormatReader::AudioDataPromise;
using VideoDataPromise = MediaFormatReader::VideoDataPromise;
using WaitForDataPromise = MediaFormatReader::WaitForDataPromise;
MozPromiseRequestHolder<AudioDataPromise> mAudioDataRequest;
MozPromiseRequestHolder<VideoDataPromise> mVideoDataRequest;
MozPromiseRequestHolder<WaitForDataPromise> mAudioWaitRequest;
MozPromiseRequestHolder<WaitForDataPromise> mVideoWaitRequest;
WatchManager<MediaDecoderStateMachineBase> mWatchManager;
} // namespace mozilla