gecko/content/media/webaudio/AudioDestinationNode.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 "AudioDestinationNode.h"
#include "mozilla/dom/AudioDestinationNodeBinding.h"
#include "AudioNodeEngine.h"
#include "AudioNodeStream.h"
#include "MediaStreamGraph.h"
#include "OfflineAudioCompletionEvent.h"
namespace mozilla {
namespace dom {
class OfflineDestinationNodeEngine : public AudioNodeEngine
{
public:
typedef AutoFallibleTArray<nsAutoArrayPtr<float>, 2> InputChannels;
OfflineDestinationNodeEngine(AudioDestinationNode* aNode,
uint32_t aNumberOfChannels,
uint32_t aLength,
float aSampleRate)
: AudioNodeEngine(aNode)
, mWriteIndex(0)
, mLength(aLength)
, mSampleRate(aSampleRate)
{
// These allocations might fail if content provides a huge number of
// channels or size, but it's OK since we'll deal with the failure
// gracefully.
if (mInputChannels.SetLength(aNumberOfChannels)) {
static const fallible_t fallible = fallible_t();
for (uint32_t i = 0; i < aNumberOfChannels; ++i) {
mInputChannels[i] = new(fallible) float[aLength];
if (!mInputChannels[i]) {
mInputChannels.Clear();
break;
}
}
}
}
virtual void ProduceAudioBlock(AudioNodeStream* aStream,
const AudioChunk& aInput,
AudioChunk* aOutput,
bool* aFinished) MOZ_OVERRIDE
{
// Do this just for the sake of political correctness; this output
// will not go anywhere.
*aOutput = aInput;
// Handle the case of allocation failure in the input buffer
if (mInputChannels.IsEmpty()) {
return;
}
// Record our input buffer
MOZ_ASSERT(mWriteIndex < mLength, "How did this happen?");
const uint32_t duration = std::min(WEBAUDIO_BLOCK_SIZE, mLength - mWriteIndex);
const uint32_t commonChannelCount = std::min(mInputChannels.Length(),
aInput.mChannelData.Length());
// First, copy as many channels in the input as we have
for (uint32_t i = 0; i < commonChannelCount; ++i) {
if (aInput.IsNull()) {
PodZero(mInputChannels[i] + mWriteIndex, duration);
} else {
const float* inputBuffer = static_cast<const float*>(aInput.mChannelData[i]);
if (duration == WEBAUDIO_BLOCK_SIZE) {
// Use the optimized version of the copy with scale operation
AudioBlockCopyChannelWithScale(inputBuffer, aInput.mVolume,
mInputChannels[i] + mWriteIndex);
} else {
if (aInput.mVolume == 1.0f) {
PodCopy(mInputChannels[i] + mWriteIndex, inputBuffer, duration);
} else {
for (uint32_t j = 0; j < duration; ++j) {
mInputChannels[i][mWriteIndex + j] = aInput.mVolume * inputBuffer[j];
}
}
}
}
}
// Then, silence all of the remaining channels
for (uint32_t i = commonChannelCount; i < mInputChannels.Length(); ++i) {
PodZero(mInputChannels[i] + mWriteIndex, duration);
}
mWriteIndex += duration;
if (mWriteIndex == mLength) {
SendBufferToMainThread(aStream);
*aFinished = true;
}
}
void SendBufferToMainThread(AudioNodeStream* aStream)
{
class Command : public nsRunnable
{
public:
Command(AudioNodeStream* aStream,
InputChannels& aInputChannels,
uint32_t aLength,
float aSampleRate)
: mStream(aStream)
, mLength(aLength)
, mSampleRate(aSampleRate)
{
mInputChannels.SwapElements(aInputChannels);
}
NS_IMETHODIMP Run()
{
// If it's not safe to run scripts right now, schedule this to run later
if (!nsContentUtils::IsSafeToRunScript()) {
nsContentUtils::AddScriptRunner(this);
return NS_OK;
}
nsRefPtr<AudioContext> context;
{
MutexAutoLock lock(mStream->Engine()->NodeMutex());
AudioNode* node = mStream->Engine()->Node();
if (node) {
context = node->Context();
}
}
if (!context) {
return NS_OK;
}
AutoPushJSContext cx(context->GetJSContext());
if (cx) {
JSAutoRequest ar(cx);
// Create the input buffer
nsRefPtr<AudioBuffer> renderedBuffer = new AudioBuffer(context,
mLength,
mSampleRate);
if (!renderedBuffer->InitializeBuffers(mInputChannels.Length(), cx)) {
return NS_OK;
}
for (uint32_t i = 0; i < mInputChannels.Length(); ++i) {
renderedBuffer->SetRawChannelContents(cx, i, mInputChannels[i]);
}
nsRefPtr<OfflineAudioCompletionEvent> event =
new OfflineAudioCompletionEvent(context, nullptr, nullptr);
event->InitEvent(renderedBuffer);
context->DispatchTrustedEvent(event);
}
return NS_OK;
}
private:
nsRefPtr<AudioNodeStream> mStream;
InputChannels mInputChannels;
uint32_t mLength;
float mSampleRate;
};
// Empty out the source array to make sure we don't attempt to collect
// more input data in the future.
NS_DispatchToMainThread(new Command(aStream, mInputChannels, mLength, mSampleRate));
}
private:
// The input to the destination node is recorded in the mInputChannels buffer.
// When this buffer fills up with mLength frames, the buffered input is sent
// to the main thread in order to dispatch OfflineAudioCompletionEvent.
InputChannels mInputChannels;
// An index representing the next offset in mInputChannels to be written to.
uint32_t mWriteIndex;
// How many frames the OfflineAudioContext intends to produce.
uint32_t mLength;
float mSampleRate;
};
NS_IMPL_ISUPPORTS_INHERITED0(AudioDestinationNode, AudioNode)
AudioDestinationNode::AudioDestinationNode(AudioContext* aContext,
bool aIsOffline,
uint32_t aNumberOfChannels,
uint32_t aLength,
float aSampleRate)
: AudioNode(aContext,
aIsOffline ? aNumberOfChannels : 2,
ChannelCountMode::Explicit,
ChannelInterpretation::Speakers)
, mFramesToProduce(aLength)
{
MediaStreamGraph* graph = aIsOffline ?
MediaStreamGraph::CreateNonRealtimeInstance() :
MediaStreamGraph::GetInstance();
AudioNodeEngine* engine = aIsOffline ?
new OfflineDestinationNodeEngine(this, aNumberOfChannels,
aLength, aSampleRate) :
new AudioNodeEngine(this);
mStream = graph->CreateAudioNodeStream(engine, MediaStreamGraph::EXTERNAL_STREAM);
}
uint32_t
AudioDestinationNode::MaxChannelCount() const
{
return Context()->MaxChannelCount();
}
void
AudioDestinationNode::SetChannelCount(uint32_t aChannelCount, ErrorResult& aRv)
{
if (aChannelCount > MaxChannelCount()) {
aRv.Throw(NS_ERROR_DOM_INDEX_SIZE_ERR);
return;
}
AudioNode::SetChannelCount(aChannelCount, aRv);
}
void
AudioDestinationNode::DestroyGraph()
{
MOZ_ASSERT(Context() && Context()->IsOffline(),
"Should only be called on a valid OfflineAudioContext");
MediaStreamGraph::DestroyNonRealtimeInstance(mStream->Graph());
}
JSObject*
AudioDestinationNode::WrapObject(JSContext* aCx, JS::Handle<JSObject*> aScope)
{
return AudioDestinationNodeBinding::Wrap(aCx, aScope, this);
}
void
AudioDestinationNode::StartRendering()
{
mStream->Graph()->StartNonRealtimeProcessing(mFramesToProduce);
}
}
}