gecko-dev/dom/media/AudioCaptureStream.cpp

133 строки
4.7 KiB
C++
Исходник Обычный вид История

/* -*- 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 "MediaStreamGraphImpl.h"
#include "mozilla/MathAlgorithms.h"
#include "mozilla/unused.h"
#include "AudioSegment.h"
#include "mozilla/Logging.h"
#include "mozilla/Attributes.h"
#include "AudioCaptureStream.h"
#include "ImageContainer.h"
#include "AudioNodeEngine.h"
#include "AudioNodeStream.h"
#include "AudioNodeExternalInputStream.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;
AudioCaptureStream::AudioCaptureStream(DOMMediaStream* aWrapper, TrackID aTrackId)
: ProcessedMediaStream(aWrapper), mTrackId(aTrackId), mTrackCreated(false)
{
MOZ_ASSERT(NS_IsMainThread());
MOZ_COUNT_CTOR(AudioCaptureStream);
mMixer.AddCallback(this);
}
AudioCaptureStream::~AudioCaptureStream()
{
MOZ_COUNT_DTOR(AudioCaptureStream);
mMixer.RemoveCallback(this);
}
void
AudioCaptureStream::ProcessInput(GraphTime aFrom, GraphTime aTo,
uint32_t aFlags)
{
uint32_t inputCount = mInputs.Length();
StreamBuffer::Track* track = EnsureTrack(mTrackId);
// Notify the DOM everything is in order.
if (!mTrackCreated) {
for (uint32_t i = 0; i < mListeners.Length(); i++) {
MediaStreamListener* l = mListeners[i];
AudioSegment tmp;
l->NotifyQueuedTrackChanges(
Graph(), mTrackId, 0, MediaStreamListener::TRACK_EVENT_CREATED, tmp);
l->NotifyFinishedTrackCreation(Graph());
}
mTrackCreated = true;
}
// If the captured stream is connected back to a object on the page (be it an
// HTMLMediaElement with a stream as source, or an AudioContext), a cycle
// situation occur. This can work if it's an AudioContext with at least one
// DelayNode, but the MSG will mute the whole cycle otherwise.
if (mFinished || InMutedCycle() || inputCount == 0) {
track->Get<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++) {
MediaStream* s = mInputs[i]->GetSource();
StreamBuffer::TrackIter tracks(s->GetStreamBuffer(), MediaSegment::AUDIO);
while (!tracks.IsEnded()) {
AudioSegment* inputSegment = tracks->Get<AudioSegment>();
StreamTime inputStart = s->GraphTimeToStreamTimeWithBlocking(aFrom);
StreamTime inputEnd = s->GraphTimeToStreamTimeWithBlocking(aTo);
AudioSegment toMix;
toMix.AppendSlice(*inputSegment, inputStart, inputEnd);
// Care for streams blocked in the [aTo, aFrom] range.
if (inputEnd - inputStart < aTo - aFrom) {
toMix.AppendNullData((aTo - aFrom) - (inputEnd - inputStart));
}
toMix.Mix(mMixer, MONO, Graph()->GraphRate());
tracks.Next();
}
}
// This calls MixerCallback below
mMixer.FinishMixing();
}
// Regardless of the status of the input tracks, we go foward.
mBuffer.AdvanceKnownTracksTime(GraphTimeToStreamTimeWithBlocking((aTo)));
}
void
AudioCaptureStream::MixerCallback(AudioDataValue* aMixedBuffer,
AudioSampleFormat aFormat, uint32_t aChannels,
uint32_t aFrames, uint32_t aSampleRate)
{
nsAutoTArray<nsTArray<AudioDataValue>, MONO> output;
nsAutoTArray<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>(&output);
chunk.mDuration = aFrames;
chunk.mBufferFormat = aFormat;
chunk.mVolume = 1.0f;
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 to out track.
EnsureTrack(mTrackId)->Get<AudioSegment>()->AppendAndConsumeChunk(&chunk);
}
}