content/media/MediaMetadataManager.h
author Mike Hommey <mh+mozilla@glandium.org>
Thu, 26 Jun 2014 15:26:16 +0900
changeset 211787 29bbf1aba13a4ebf800dd26810697cf4d25abc4b
parent 203980 f1755dd27a44d889c44adb476ad0723dce7a3e82
child 212963 7691b13459f4f72dc627af41dc0d83fa189cc7f8
permissions -rw-r--r--
Bug 1030598 - Fix make export race condition after bug 1028563. r=gps

/* -*- 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 "VideoUtils.h"
#include "mozilla/LinkedList.h"
#include "AbstractMediaDecoder.h"
#include "nsAutoPtr.h"

namespace mozilla {

  // 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:
      // The time, in microseconds, at which those metadata should be available.
      int64_t mPublishTime;
      // The metadata. The ownership is transfered to the element when dispatching to
      // the main threads.
      nsAutoPtr<MetadataTags> mTags;
      // The sample rate of this media.
      int mRate;
      // The number of channel of this media.
      int mChannels;
      // True if this media has an audio track.
      bool mHasAudio;
      // True if this media has a video track.
      bool mHasVideo;
  };

  // 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;
        }
      }
      void QueueMetadata(TimedMetadata* aMetadata) {
        mMetadataQueue.insertBack(aMetadata);
      }

      void DispatchMetadataIfNeeded(AbstractMediaDecoder* aDecoder, double aCurrentTime) {
        TimedMetadata* metadata = mMetadataQueue.getFirst();
        while (metadata && aCurrentTime >= static_cast<double>(metadata->mPublishTime) / USECS_PER_S) {
          nsCOMPtr<nsIRunnable> metadataUpdatedEvent =
            new AudioMetadataEventRunner(aDecoder,
                                         metadata->mChannels,
                                         metadata->mRate,
                                         metadata->mHasAudio,
                                         metadata->mHasVideo,
                                         metadata->mTags.forget());
          NS_DispatchToMainThread(metadataUpdatedEvent);
          delete mMetadataQueue.popFirst();
          metadata = mMetadataQueue.getFirst();
        }
      }
    protected:
      LinkedList<TimedMetadata> mMetadataQueue;
  };
}

#endif