Source code

Revision control

Other Tools

/* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*-*/
/* 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 "MediaTrackGraphImpl.h"
#include "MediaTrackListener.h"
#include "mozilla/MathAlgorithms.h"
#include "mozilla/Unused.h"
#include "AudioSegment.h"
#include "mozilla/Logging.h"
#include "mozilla/Attributes.h"
#include "AudioCaptureTrack.h"
#include "ImageContainer.h"
#include "AudioNodeEngine.h"
#include "AudioNodeTrack.h"
#include "AudioNodeExternalInputTrack.h"
#include "webaudio/MediaStreamAudioDestinationNode.h"
#include <algorithm>
#include "DOMMediaStream.h"
using namespace mozilla::layers;
using namespace mozilla::dom;
using namespace mozilla::gfx;
namespace mozilla {
// We are mixing to mono until PeerConnection can accept stereo
static const uint32_t MONO = 1;
AudioCaptureTrack::AudioCaptureTrack(TrackRate aRate)
: ProcessedMediaTrack(aRate, MediaSegment::AUDIO, new AudioSegment()),
mStarted(false) {
MOZ_ASSERT(NS_IsMainThread());
MOZ_COUNT_CTOR(AudioCaptureTrack);
mMixer.AddCallback(WrapNotNull(this));
}
AudioCaptureTrack::~AudioCaptureTrack() {
MOZ_COUNT_DTOR(AudioCaptureTrack);
mMixer.RemoveCallback(this);
}
void AudioCaptureTrack::Start() {
class Message : public ControlMessage {
public:
explicit Message(AudioCaptureTrack* aTrack)
: ControlMessage(aTrack), mTrack(aTrack) {}
virtual void Run() { mTrack->mStarted = true; }
protected:
AudioCaptureTrack* mTrack;
};
GraphImpl()->AppendMessage(MakeUnique<Message>(this));
}
void AudioCaptureTrack::ProcessInput(GraphTime aFrom, GraphTime aTo,
uint32_t aFlags) {
if (!mStarted) {
return;
}
uint32_t inputCount = mInputs.Length();
if (mEnded) {
return;
}
// If the captured track is connected back to a object on the page (be it an
// HTMLMediaElement with a track as source, or an AudioContext), a cycle
// situation occur. This can work if it's an AudioContext with at least one
// DelayNode, but the MTG will mute the whole cycle otherwise.
if (InMutedCycle() || inputCount == 0) {
GetData<AudioSegment>()->AppendNullData(aTo - aFrom);
} else {
// We mix down all the tracks of all inputs, to a stereo track. Everything
// is {up,down}-mixed to stereo.
mMixer.StartMixing();
AudioSegment output;
for (uint32_t i = 0; i < inputCount; i++) {
MediaTrack* s = mInputs[i]->GetSource();
AudioSegment* inputSegment = s->GetData<AudioSegment>();
TrackTime inputStart = s->GraphTimeToTrackTimeWithBlocking(aFrom);
TrackTime inputEnd = s->GraphTimeToTrackTimeWithBlocking(aTo);
AudioSegment toMix;
if (s->Ended() && inputSegment->GetDuration() <= inputStart) {
toMix.AppendNullData(aTo - aFrom);
} else {
toMix.AppendSlice(*inputSegment, inputStart, inputEnd);
// Care for tracks blocked in the [aTo, aFrom] range.
if (inputEnd - inputStart < aTo - aFrom) {
toMix.AppendNullData((aTo - aFrom) - (inputEnd - inputStart));
}
}
toMix.Mix(mMixer, MONO, Graph()->GraphRate());
}
// This calls MixerCallback below
mMixer.FinishMixing();
}
}
void AudioCaptureTrack::MixerCallback(AudioDataValue* aMixedBuffer,
AudioSampleFormat aFormat,
uint32_t aChannels, uint32_t aFrames,
uint32_t aSampleRate) {
AutoTArray<nsTArray<AudioDataValue>, MONO> output;
AutoTArray<const AudioDataValue*, MONO> bufferPtrs;
output.SetLength(MONO);
bufferPtrs.SetLength(MONO);
uint32_t written = 0;
// We need to copy here, because the mixer will reuse the storage, we should
// not hold onto it. Buffers are in planar format.
for (uint32_t channel = 0; channel < aChannels; channel++) {
AudioDataValue* out = output[channel].AppendElements(aFrames);
PodCopy(out, aMixedBuffer + written, aFrames);
bufferPtrs[channel] = out;
written += aFrames;
}
AudioChunk chunk;
chunk.mBuffer =
new mozilla::SharedChannelArrayBuffer<AudioDataValue>(std::move(output));
chunk.mDuration = aFrames;
chunk.mBufferFormat = aFormat;
chunk.mChannelData.SetLength(MONO);
for (uint32_t channel = 0; channel < aChannels; channel++) {
chunk.mChannelData[channel] = bufferPtrs[channel];
}
// Now we have mixed data, simply append it.
GetData<AudioSegment>()->AppendAndConsumeChunk(&chunk);
}
} // namespace mozilla