/* -*- 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(MediaMetadataManager_h__) #define MediaMetadataManager_h__ #include "mozilla/AbstractThread.h" #include "mozilla/LinkedList.h" #include "nsAutoPtr.h" #include "AbstractMediaDecoder.h" #include "MediaEventSource.h" #include "TimeUnits.h" #include "VideoUtils.h" namespace mozilla { class TimedMetadata; typedef MediaEventProducerExc<TimedMetadata> TimedMetadataEventProducer; typedef MediaEventSourceExc<TimedMetadata> TimedMetadataEventSource; // A struct that contains the metadata of a media, and the time at which those // metadata should start to be reported. class TimedMetadata : public LinkedListElement<TimedMetadata> { public: TimedMetadata(const media::TimeUnit& aPublishTime, nsAutoPtr<MetadataTags>&& aTags, nsAutoPtr<MediaInfo>&& aInfo) : mPublishTime(aPublishTime) , mTags(Move(aTags)) , mInfo(Move(aInfo)) {} // Define our move constructor because we don't want to move the members of // LinkedListElement to change the list. TimedMetadata(TimedMetadata&& aOther) : mPublishTime(aOther.mPublishTime) , mTags(Move(aOther.mTags)) , mInfo(Move(aOther.mInfo)) {} // The time, in microseconds, at which those metadata should be available. media::TimeUnit mPublishTime; // The metadata. The ownership is transfered to the element when dispatching to // the main threads. nsAutoPtr<MetadataTags> mTags; // The media info, including the info of audio tracks and video tracks. // The ownership is transfered to MediaDecoder when dispatching to the // main thread. nsAutoPtr<MediaInfo> mInfo; }; // This class encapsulate the logic to give the metadata from the reader to // the content, at the right time. class MediaMetadataManager { public: ~MediaMetadataManager() { TimedMetadata* element; while((element = mMetadataQueue.popFirst()) != nullptr) { delete element; } } // Connect to an event source to receive TimedMetadata events. void Connect(TimedMetadataEventSource& aEvent, AbstractThread* aThread) { mListener = aEvent.Connect( aThread, this, &MediaMetadataManager::OnMetadataQueued); } // Stop receiving TimedMetadata events. void Disconnect() { mListener.Disconnect(); } // Return an event source through which we will send TimedMetadata events // when playback position reaches the publish time. TimedMetadataEventSource& TimedMetadataEvent() { return mTimedMetadataEvent; } void DispatchMetadataIfNeeded(const media::TimeUnit& aCurrentTime) { TimedMetadata* metadata = mMetadataQueue.getFirst(); while (metadata && aCurrentTime >= metadata->mPublishTime) { // Our listener will figure out what to do with TimedMetadata. mTimedMetadataEvent.Notify(Move(*metadata)); delete mMetadataQueue.popFirst(); metadata = mMetadataQueue.getFirst(); } } protected: void OnMetadataQueued(TimedMetadata&& aMetadata) { mMetadataQueue.insertBack(new TimedMetadata(Move(aMetadata))); } LinkedList<TimedMetadata> mMetadataQueue; MediaEventListener mListener; TimedMetadataEventProducer mTimedMetadataEvent; }; } // namespace mozilla #endif