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/* -*- 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 "MediaTrackGraph.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);
}
AudioCaptureTrack::~AudioCaptureTrack() { MOZ_COUNT_DTOR(AudioCaptureTrack); }
void AudioCaptureTrack::Start() {
QueueControlMessageWithNoShutdown(
[self = RefPtr{this}, this] { mStarted = true; });
}
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());
}
AudioChunk* mixed = mMixer.MixedChunk();
MOZ_ASSERT(mixed->ChannelCount() == MONO);
// Now we have mixed data, simply append it.
GetData<AudioSegment>()->AppendAndConsumeChunk(std::move(*mixed));
}
}
uint32_t AudioCaptureTrack::NumberOfChannels() const {
return GetData<AudioSegment>()->MaxChannelCount();
}
} // namespace mozilla
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