gecko-dev/content/media/MediaMetadataManager.h

71 строка
2.6 KiB
C++

/* -*- 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 mozilla::AudioMetadataEventRunner(aDecoder,
metadata->mChannels,
metadata->mRate,
metadata->mHasAudio,
metadata->mHasVideo,
metadata->mTags.forget());
NS_DispatchToMainThread(metadataUpdatedEvent, NS_DISPATCH_NORMAL);
mMetadataQueue.popFirst();
metadata = mMetadataQueue.getFirst();
}
}
protected:
LinkedList<TimedMetadata> mMetadataQueue;
};
}
#endif