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/* -*- 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 */
#ifndef MediaRecorder_h
#define MediaRecorder_h
#include "mozilla/dom/MediaRecorderBinding.h"
#include "mozilla/DOMEventTargetHelper.h"
#include "mozilla/MozPromise.h"
#include "nsIDocumentActivity.h"
// Max size for allowing queue encoded data in memory
namespace mozilla {
class AudioNodeTrack;
class DOMMediaStream;
class ErrorResult;
struct MediaRecorderOptions;
class GlobalObject;
namespace dom {
class AudioNode;
class BlobImpl;
class Document;
class DOMException;
* Implementation of
* The MediaRecorder accepts a MediaStream as input passed from an application.
* When the MediaRecorder starts, a MediaEncoder will be created and accepts the
* MediaStreamTracks in the MediaStream as input source. For each track it
* creates a TrackEncoder.
* The MediaEncoder automatically encodes and muxes data from the tracks by the
* given MIME type, then it stores this data into a MutableBlobStorage object.
* When a timeslice is set and the MediaEncoder has stored enough data to fill
* the timeslice, it extracts a Blob from the storage and passes it to
* MediaRecorder. On RequestData() or Stop(), the MediaEncoder extracts the blob
* from the storage and returns it to MediaRecorder through a MozPromise.
* Thread model: When the recorder starts, it creates a worker thread (called
* the encoder thread) that does all the heavy lifting - encoding, time keeping,
* muxing.
class MediaRecorder final : public DOMEventTargetHelper,
public nsIDocumentActivity {
class Session;
explicit MediaRecorder(nsPIDOMWindowInner* aOwnerWindow);
static nsTArray<RefPtr<Session>> GetSessions();
// nsWrapperCache
JSObject* WrapObject(JSContext* aCx,
JS::Handle<JSObject*> aGivenProto) override;
// WebIDL
// Start recording.
void Start(const Optional<uint32_t>& timeSlice, ErrorResult& aResult);
// Stop recording.
void Stop(ErrorResult& aResult);
// Pause a recording.
void Pause(ErrorResult& aResult);
// Resume a paused recording.
void Resume(ErrorResult& aResult);
// Extracts buffered data and fires the dataavailable event.
void RequestData(ErrorResult& aResult);
// Return the The DOMMediaStream passed from UA.
DOMMediaStream* Stream() const { return mStream; }
// Return the current encoding MIME type selected by the MediaEncoder.
void GetMimeType(nsString& aMimeType);
// The current state of the MediaRecorder object.
RecordingState State() const { return mState; }
static bool IsTypeSupported(GlobalObject& aGlobal,
const nsAString& aMIMEType);
static bool IsTypeSupported(const nsAString& aMIMEType);
// Construct a recorder with a DOM media stream object as its source.
static already_AddRefed<MediaRecorder> Constructor(
const GlobalObject& aGlobal, DOMMediaStream& aStream,
const MediaRecorderOptions& aOptions, ErrorResult& aRv);
// Construct a recorder with a Web Audio destination node as its source.
static already_AddRefed<MediaRecorder> Constructor(
const GlobalObject& aGlobal, AudioNode& aAudioNode,
uint32_t aAudioNodeOutput, const MediaRecorderOptions& aOptions,
ErrorResult& aRv);
* Measure the size of the buffer, and heap memory in bytes occupied by
* mAudioEncoder and mVideoEncoder.
typedef MozPromise<size_t, size_t, true> SizeOfPromise;
RefPtr<SizeOfPromise> SizeOfExcludingThis(
mozilla::MallocSizeOf aMallocSizeOf);
// EventHandler
uint32_t AudioBitsPerSecond() const { return mAudioBitsPerSecond; }
uint32_t VideoBitsPerSecond() const { return mVideoBitsPerSecond; }
virtual ~MediaRecorder();
MediaRecorder& operator=(const MediaRecorder& x) = delete;
// Create dataavailable event with Blob data and it runs in main thread
nsresult CreateAndDispatchBlobEvent(BlobImpl* aBlobImpl);
// Creating a simple event to notify UA simple event.
void DispatchSimpleEvent(const nsAString& aStr);
// Creating a error event with message.
void NotifyError(nsresult aRv);
MediaRecorder(const MediaRecorder& x) = delete; // prevent bad usage
// Remove session pointer.
void RemoveSession(Session* aSession);
// Create DOMExceptions capturing the JS stack for async errors. These are
// created ahead of time rather than on demand when firing an error as the JS
// stack of the operation that started the async behavior will not be
// available at the time the error event is fired. Note, depending on when
// this is called there may not be a JS stack to capture.
void InitializeDomExceptions();
// Runs the "Inactivate the recorder" algorithm.
void Inactivate();
// Stop the recorder and its internal session. This should be used by
// sessions that are in the process of being destroyed.
void StopForSessionDestruction();
// DOM wrapper for source media stream. Will be null when input is audio node.
RefPtr<DOMMediaStream> mStream;
// Source audio node. Will be null when input is a media stream.
RefPtr<AudioNode> mAudioNode;
// Source audio node's output index. Will be zero when input is a media
// stream.
uint32_t mAudioNodeOutput = 0;
// The current state of the MediaRecorder object.
RecordingState mState = RecordingState::Inactive;
// Hold the sessions reference and clean it when the DestroyRunnable for a
// session is running.
nsTArray<RefPtr<Session>> mSessions;
RefPtr<Document> mDocument;
nsString mMimeType;
nsString mConstrainedMimeType;
uint32_t mAudioBitsPerSecond = 0;
uint32_t mVideoBitsPerSecond = 0;
Maybe<uint32_t> mConstrainedBitsPerSecond;
// DOMExceptions that are created early and possibly thrown in NotifyError.
// Creating them early allows us to capture the JS stack for which cannot be
// done at the time the error event is fired.
RefPtr<DOMException> mOtherDomException;
RefPtr<DOMException> mSecurityDomException;
RefPtr<DOMException> mUnknownDomException;
// Register MediaRecorder into Document to listen the activity changes.
void RegisterActivityObserver();
void UnRegisterActivityObserver();
bool CheckPermission(const nsString& aType);
} // namespace dom
} // namespace mozilla