gecko/content/media/webaudio/MediaStreamAudioDestinationNode.cpp

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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 http://mozilla.org/MPL/2.0/. */
#include "MediaStreamAudioDestinationNode.h"
#include "nsIDocument.h"
#include "mozilla/dom/MediaStreamAudioDestinationNodeBinding.h"
#include "AudioNodeEngine.h"
#include "AudioNodeStream.h"
#include "DOMMediaStream.h"
#include "TrackUnionStream.h"
namespace mozilla {
namespace dom {
NS_IMPL_CYCLE_COLLECTION_INHERITED_1(MediaStreamAudioDestinationNode, AudioNode, mDOMStream)
NS_INTERFACE_MAP_BEGIN_CYCLE_COLLECTION_INHERITED(MediaStreamAudioDestinationNode)
NS_INTERFACE_MAP_END_INHERITING(AudioNode)
NS_IMPL_ADDREF_INHERITED(MediaStreamAudioDestinationNode, AudioNode)
NS_IMPL_RELEASE_INHERITED(MediaStreamAudioDestinationNode, AudioNode)
static const int MEDIA_STREAM_DEST_TRACK_ID = 2;
static_assert(MEDIA_STREAM_DEST_TRACK_ID != AudioNodeStream::AUDIO_TRACK,
"MediaStreamAudioDestinationNode::MEDIA_STREAM_DEST_TRACK_ID must be a different value than AudioNodeStream::AUDIO_TRACK");
class MediaStreamDestinationEngine : public AudioNodeEngine {
public:
MediaStreamDestinationEngine(AudioNode* aNode, ProcessedMediaStream* aOutputStream)
: AudioNodeEngine(aNode)
, mOutputStream(aOutputStream)
{
MOZ_ASSERT(mOutputStream);
}
virtual void ProduceAudioBlock(AudioNodeStream* aStream,
const AudioChunk& aInput,
AudioChunk* aOutput,
bool* aFinished) MOZ_OVERRIDE
{
*aOutput = aInput;
StreamBuffer::Track* track = mOutputStream->EnsureTrack(MEDIA_STREAM_DEST_TRACK_ID,
aStream->SampleRate());
AudioSegment* segment = track->Get<AudioSegment>();
segment->AppendAndConsumeChunk(aOutput);
}
private:
ProcessedMediaStream* mOutputStream;
};
// This callback is used to ensure that only the audio data for this track is audible
static bool FilterAudioNodeStreamTrack(StreamBuffer::Track* aTrack)
{
return aTrack->GetID() == MEDIA_STREAM_DEST_TRACK_ID;
}
MediaStreamAudioDestinationNode::MediaStreamAudioDestinationNode(AudioContext* aContext)
: AudioNode(aContext,
2,
ChannelCountMode::Explicit,
ChannelInterpretation::Speakers)
, mDOMStream(DOMAudioNodeMediaStream::CreateTrackUnionStream(GetOwner(),
MOZ_THIS_IN_INITIALIZER_LIST(),
DOMMediaStream::HINT_CONTENTS_AUDIO))
{
TrackUnionStream* tus = static_cast<TrackUnionStream*>(mDOMStream->GetStream());
MOZ_ASSERT(tus == mDOMStream->GetStream()->AsProcessedStream());
tus->SetTrackIDFilter(FilterAudioNodeStreamTrack);
MediaStreamDestinationEngine* engine = new MediaStreamDestinationEngine(this, tus);
mStream = aContext->Graph()->CreateAudioNodeStream(engine, MediaStreamGraph::INTERNAL_STREAM);
mPort = tus->AllocateInputPort(mStream, 0);
nsIDocument* doc = aContext->GetParentObject()->GetExtantDoc();
if (doc) {
mDOMStream->CombineWithPrincipal(doc->NodePrincipal());
}
}
void
MediaStreamAudioDestinationNode::DestroyMediaStream()
{
AudioNode::DestroyMediaStream();
if (mPort) {
mPort->Destroy();
mPort = nullptr;
}
}
JSObject*
MediaStreamAudioDestinationNode::WrapObject(JSContext* aCx, JS::Handle<JSObject*> aScope)
{
return MediaStreamAudioDestinationNodeBinding::Wrap(aCx, aScope, this);
}
}
}