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133 lines
4.4 KiB
C++
133 lines
4.4 KiB
C++
/* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
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/* vim:set ts=2 sw=2 sts=2 et cindent: */
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/* This Source Code Form is subject to the terms of the Mozilla Public
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* License, v. 2.0. If a copy of the MPL was not distributed with this
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* file, You can obtain one at http://mozilla.org/MPL/2.0/. */
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#include "GainNode.h"
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#include "mozilla/dom/GainNodeBinding.h"
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#include "AudioNodeEngine.h"
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#include "AudioNodeStream.h"
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#include "AudioDestinationNode.h"
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#include "WebAudioUtils.h"
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namespace mozilla {
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namespace dom {
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NS_IMPL_CYCLE_COLLECTION_INHERITED_1(GainNode, AudioNode,
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mGain)
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NS_INTERFACE_MAP_BEGIN_CYCLE_COLLECTION_INHERITED(GainNode)
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NS_INTERFACE_MAP_END_INHERITING(AudioNode)
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NS_IMPL_ADDREF_INHERITED(GainNode, AudioNode)
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NS_IMPL_RELEASE_INHERITED(GainNode, AudioNode)
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class GainNodeEngine : public AudioNodeEngine
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{
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public:
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GainNodeEngine(AudioNode* aNode, AudioDestinationNode* aDestination)
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: AudioNodeEngine(aNode)
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, mSource(nullptr)
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, mDestination(static_cast<AudioNodeStream*> (aDestination->Stream()))
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// Keep the default value in sync with the default value in GainNode::GainNode.
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, mGain(1.f)
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{
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}
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void SetSourceStream(AudioNodeStream* aSource)
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{
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mSource = aSource;
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}
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enum Parameters {
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GAIN
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};
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void SetTimelineParameter(uint32_t aIndex,
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const AudioParamTimeline& aValue,
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TrackRate aSampleRate) MOZ_OVERRIDE
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{
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switch (aIndex) {
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case GAIN:
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MOZ_ASSERT(mSource && mDestination);
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mGain = aValue;
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WebAudioUtils::ConvertAudioParamToTicks(mGain, mSource, mDestination);
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break;
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default:
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NS_ERROR("Bad GainNodeEngine TimelineParameter");
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}
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}
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virtual void ProduceAudioBlock(AudioNodeStream* aStream,
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const AudioChunk& aInput,
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AudioChunk* aOutput,
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bool* aFinished)
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{
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MOZ_ASSERT(mSource == aStream, "Invalid source stream");
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if (aInput.IsNull()) {
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// If input is silent, so is the output
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aOutput->SetNull(WEBAUDIO_BLOCK_SIZE);
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} else if (mGain.HasSimpleValue()) {
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// Optimize the case where we only have a single value set as the volume
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*aOutput = aInput;
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aOutput->mVolume *= mGain.GetValue();
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} else {
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// First, compute a vector of gains for each track tick based on the
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// timeline at hand, and then for each channel, multiply the values
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// in the buffer with the gain vector.
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AllocateAudioBlock(aInput.mChannelData.Length(), aOutput);
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// Compute the gain values for the duration of the input AudioChunk
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// XXX we need to add a method to AudioEventTimeline to compute this buffer directly.
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float computedGain[WEBAUDIO_BLOCK_SIZE];
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for (size_t counter = 0; counter < WEBAUDIO_BLOCK_SIZE; ++counter) {
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TrackTicks tick = aStream->GetCurrentPosition();
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computedGain[counter] = mGain.GetValueAtTime(tick, counter) * aInput.mVolume;
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}
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// Apply the gain to the output buffer
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for (size_t channel = 0; channel < aOutput->mChannelData.Length(); ++channel) {
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const float* inputBuffer = static_cast<const float*> (aInput.mChannelData[channel]);
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float* buffer = static_cast<float*> (const_cast<void*>
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(aOutput->mChannelData[channel]));
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AudioBlockCopyChannelWithScale(inputBuffer, computedGain, buffer);
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}
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}
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}
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AudioNodeStream* mSource;
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AudioNodeStream* mDestination;
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AudioParamTimeline mGain;
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};
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GainNode::GainNode(AudioContext* aContext)
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: AudioNode(aContext,
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2,
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ChannelCountMode::Max,
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ChannelInterpretation::Speakers)
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, mGain(new AudioParam(MOZ_THIS_IN_INITIALIZER_LIST(),
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SendGainToStream, 1.0f))
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{
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GainNodeEngine* engine = new GainNodeEngine(this, aContext->Destination());
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mStream = aContext->Graph()->CreateAudioNodeStream(engine, MediaStreamGraph::INTERNAL_STREAM);
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engine->SetSourceStream(static_cast<AudioNodeStream*> (mStream.get()));
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}
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JSObject*
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GainNode::WrapObject(JSContext* aCx, JS::Handle<JSObject*> aScope)
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{
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return GainNodeBinding::Wrap(aCx, aScope, this);
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}
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void
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GainNode::SendGainToStream(AudioNode* aNode)
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{
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GainNode* This = static_cast<GainNode*>(aNode);
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SendTimelineParameterToStream(This, GainNodeEngine::GAIN, *This->mGain);
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}
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}
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}
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