Source code

Revision control

Copy as Markdown

Other Tools

/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
/* vim: set ts=8 sts=2 et sw=2 tw=80: */
/* 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 */
#ifndef ChannelMediaDecoder_h_
#define ChannelMediaDecoder_h_
#include "MediaDecoder.h"
#include "MediaResourceCallback.h"
#include "MediaChannelStatistics.h"
class nsIChannel;
class nsIStreamListener;
namespace mozilla {
class BaseMediaResource;
DDLoggedTypeDeclNameAndBase(ChannelMediaDecoder, MediaDecoder);
class ChannelMediaDecoder
: public MediaDecoder,
public DecoderDoctorLifeLogger<ChannelMediaDecoder> {
// 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;
explicit ResourceCallback(AbstractThread* aMainThread);
// Start to receive notifications from ResourceCallback.
void Connect(ChannelMediaDecoder* aDecoder);
// Called upon shutdown to stop receiving notifications.
void Disconnect();
/* MediaResourceCallback functions */
AbstractThread* AbstractMainThread() const override;
MediaDecoderOwner* GetMediaOwner() const override;
void NotifyNetworkError(const MediaResult& aError) override;
void NotifyDataArrived() override;
void NotifyDataEnded(nsresult aStatus) override;
void NotifyPrincipalChanged() override;
void NotifySuspendedStatusChanged(bool aSuspendedByCache) override;
static void TimerCallback(nsITimer* aTimer, void* aClosure);
// The decoder to send notifications. Main-thread only.
ChannelMediaDecoder* mDecoder = nullptr;
nsCOMPtr<nsITimer> mTimer;
bool mTimerArmed = false;
const RefPtr<AbstractThread> mAbstractMainThread;
void ShutdownInternal() override;
void OnPlaybackEvent(MediaPlaybackEvent&& aEvent) override;
void DurationChanged() override;
void MetadataLoaded(UniquePtr<MediaInfo> aInfo, UniquePtr<MetadataTags> aTags,
MediaDecoderEventVisibility aEventVisibility) override;
void NotifyPrincipalChanged() override;
RefPtr<ResourceCallback> mResourceCallback;
RefPtr<BaseMediaResource> mResource;
explicit ChannelMediaDecoder(MediaDecoderInit& aInit);
void GetDebugInfo(dom::MediaDecoderDebugInfo& aInfo);
// Create a decoder for the given aType. Returns null if we were unable
// to create the decoder, for example because the requested MIME type in
// the init struct was unsupported.
static already_AddRefed<ChannelMediaDecoder> Create(
MediaDecoderInit& aInit, DecoderDoctorDiagnostics* aDiagnostics);
void Shutdown() override;
bool CanClone();
// Create a new decoder of the same type as this one.
already_AddRefed<ChannelMediaDecoder> Clone(MediaDecoderInit& aInit);
nsresult Load(nsIChannel* aChannel, bool aIsPrivateBrowsing,
nsIStreamListener** aStreamListener);
void AddSizeOfResources(ResourceSizes* aSizes) override;
already_AddRefed<nsIPrincipal> GetCurrentPrincipal() override;
bool HadCrossOriginRedirects() override;
bool IsTransportSeekable() override;
void SetLoadInBackground(bool aLoadInBackground) override;
void Suspend() override;
void Resume() override;
void DownloadProgressed();
// Create a new state machine to run this decoder.
MediaDecoderStateMachineBase* CreateStateMachine(
bool aDisableExternalEngine) override;
nsresult Load(BaseMediaResource* aOriginal);
// Called by MediaResource when the download has ended.
// Called on the main thread only. aStatus is the result from OnStopRequest.
void NotifyDownloadEnded(nsresult aStatus);
// 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);
bool CanPlayThroughImpl() final;
struct PlaybackRateInfo {
uint32_t mRate; // Estimate of the current playback rate (bytes/second).
bool mReliable; // True if mRate is a reliable estimate.
// The actual playback rate computation.
static PlaybackRateInfo ComputePlaybackRate(
const MediaChannelStatistics& aStats, BaseMediaResource* aResource,
const media::TimeUnit& aDuration);
// Something has changed that could affect the computed playback rate,
// so recompute it.
static void UpdatePlaybackRate(const PlaybackRateInfo& aInfo,
BaseMediaResource* aResource);
// 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.
static MediaStatistics GetStatistics(const PlaybackRateInfo& aInfo,
BaseMediaResource* aRes,
int64_t aPlaybackPosition);
bool ShouldThrottleDownload(const MediaStatistics& aStats);
// 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).
MediaChannelStatistics mPlaybackStatistics;
// 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.
int64_t mPlaybackPosition = 0;
bool mCanPlayThrough = false;
// True if we've been notified that the ChannelMediaResource has
// a principal.
bool mInitialChannelPrincipalKnown = false;
// Set in Shutdown() when we start closing mResource, if mResource is set.
// Must resolve before we unregister the shutdown blocker.
RefPtr<GenericPromise> mResourceClosePromise;
} // namespace mozilla
#endif // ChannelMediaDecoder_h_