1.1 --- /dev/null Thu Jan 01 00:00:00 1970 +0000
1.2 +++ b/content/media/webaudio/GainNode.cpp Wed Dec 31 06:09:35 2014 +0100
1.3 @@ -0,0 +1,165 @@
1.4 +/* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
1.5 +/* vim:set ts=2 sw=2 sts=2 et cindent: */
1.6 +/* This Source Code Form is subject to the terms of the Mozilla Public
1.7 + * License, v. 2.0. If a copy of the MPL was not distributed with this
1.8 + * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
1.9 +
1.10 +#include "GainNode.h"
1.11 +#include "mozilla/dom/GainNodeBinding.h"
1.12 +#include "AudioNodeEngine.h"
1.13 +#include "AudioNodeStream.h"
1.14 +#include "AudioDestinationNode.h"
1.15 +#include "WebAudioUtils.h"
1.16 +
1.17 +namespace mozilla {
1.18 +namespace dom {
1.19 +
1.20 +NS_IMPL_CYCLE_COLLECTION_INHERITED(GainNode, AudioNode,
1.21 + mGain)
1.22 +
1.23 +NS_INTERFACE_MAP_BEGIN_CYCLE_COLLECTION_INHERITED(GainNode)
1.24 +NS_INTERFACE_MAP_END_INHERITING(AudioNode)
1.25 +
1.26 +NS_IMPL_ADDREF_INHERITED(GainNode, AudioNode)
1.27 +NS_IMPL_RELEASE_INHERITED(GainNode, AudioNode)
1.28 +
1.29 +class GainNodeEngine : public AudioNodeEngine
1.30 +{
1.31 +public:
1.32 + GainNodeEngine(AudioNode* aNode, AudioDestinationNode* aDestination)
1.33 + : AudioNodeEngine(aNode)
1.34 + , mSource(nullptr)
1.35 + , mDestination(static_cast<AudioNodeStream*> (aDestination->Stream()))
1.36 + // Keep the default value in sync with the default value in GainNode::GainNode.
1.37 + , mGain(1.f)
1.38 + {
1.39 + }
1.40 +
1.41 + void SetSourceStream(AudioNodeStream* aSource)
1.42 + {
1.43 + mSource = aSource;
1.44 + }
1.45 +
1.46 + enum Parameters {
1.47 + GAIN
1.48 + };
1.49 + void SetTimelineParameter(uint32_t aIndex,
1.50 + const AudioParamTimeline& aValue,
1.51 + TrackRate aSampleRate) MOZ_OVERRIDE
1.52 + {
1.53 + switch (aIndex) {
1.54 + case GAIN:
1.55 + MOZ_ASSERT(mSource && mDestination);
1.56 + mGain = aValue;
1.57 + WebAudioUtils::ConvertAudioParamToTicks(mGain, mSource, mDestination);
1.58 + break;
1.59 + default:
1.60 + NS_ERROR("Bad GainNodeEngine TimelineParameter");
1.61 + }
1.62 + }
1.63 +
1.64 + virtual void ProcessBlock(AudioNodeStream* aStream,
1.65 + const AudioChunk& aInput,
1.66 + AudioChunk* aOutput,
1.67 + bool* aFinished)
1.68 + {
1.69 + MOZ_ASSERT(mSource == aStream, "Invalid source stream");
1.70 +
1.71 + if (aInput.IsNull()) {
1.72 + // If input is silent, so is the output
1.73 + aOutput->SetNull(WEBAUDIO_BLOCK_SIZE);
1.74 + } else if (mGain.HasSimpleValue()) {
1.75 + // Optimize the case where we only have a single value set as the volume
1.76 + float gain = mGain.GetValue();
1.77 + if (gain == 0.0f) {
1.78 + aOutput->SetNull(WEBAUDIO_BLOCK_SIZE);
1.79 + } else {
1.80 + *aOutput = aInput;
1.81 + aOutput->mVolume *= gain;
1.82 + }
1.83 + } else {
1.84 + // First, compute a vector of gains for each track tick based on the
1.85 + // timeline at hand, and then for each channel, multiply the values
1.86 + // in the buffer with the gain vector.
1.87 + AllocateAudioBlock(aInput.mChannelData.Length(), aOutput);
1.88 +
1.89 + // Compute the gain values for the duration of the input AudioChunk
1.90 + // XXX we need to add a method to AudioEventTimeline to compute this buffer directly.
1.91 + float computedGain[WEBAUDIO_BLOCK_SIZE];
1.92 + for (size_t counter = 0; counter < WEBAUDIO_BLOCK_SIZE; ++counter) {
1.93 + TrackTicks tick = aStream->GetCurrentPosition();
1.94 + computedGain[counter] = mGain.GetValueAtTime(tick, counter) * aInput.mVolume;
1.95 + }
1.96 +
1.97 + // Apply the gain to the output buffer
1.98 + for (size_t channel = 0; channel < aOutput->mChannelData.Length(); ++channel) {
1.99 + const float* inputBuffer = static_cast<const float*> (aInput.mChannelData[channel]);
1.100 + float* buffer = static_cast<float*> (const_cast<void*>
1.101 + (aOutput->mChannelData[channel]));
1.102 + AudioBlockCopyChannelWithScale(inputBuffer, computedGain, buffer);
1.103 + }
1.104 + }
1.105 + }
1.106 +
1.107 + virtual size_t SizeOfExcludingThis(MallocSizeOf aMallocSizeOf) const MOZ_OVERRIDE
1.108 + {
1.109 + // Not owned:
1.110 + // - mSource (probably)
1.111 + // - mDestination (probably)
1.112 + // - mGain - Internal ref owned by AudioNode
1.113 + return AudioNodeEngine::SizeOfExcludingThis(aMallocSizeOf);
1.114 + }
1.115 +
1.116 + virtual size_t SizeOfIncludingThis(MallocSizeOf aMallocSizeOf) const MOZ_OVERRIDE
1.117 + {
1.118 + return aMallocSizeOf(this) + SizeOfExcludingThis(aMallocSizeOf);
1.119 + }
1.120 +
1.121 + AudioNodeStream* mSource;
1.122 + AudioNodeStream* mDestination;
1.123 + AudioParamTimeline mGain;
1.124 +};
1.125 +
1.126 +GainNode::GainNode(AudioContext* aContext)
1.127 + : AudioNode(aContext,
1.128 + 2,
1.129 + ChannelCountMode::Max,
1.130 + ChannelInterpretation::Speakers)
1.131 + , mGain(new AudioParam(MOZ_THIS_IN_INITIALIZER_LIST(),
1.132 + SendGainToStream, 1.0f))
1.133 +{
1.134 + GainNodeEngine* engine = new GainNodeEngine(this, aContext->Destination());
1.135 + mStream = aContext->Graph()->CreateAudioNodeStream(engine, MediaStreamGraph::INTERNAL_STREAM);
1.136 + engine->SetSourceStream(static_cast<AudioNodeStream*> (mStream.get()));
1.137 +}
1.138 +
1.139 +size_t
1.140 +GainNode::SizeOfExcludingThis(MallocSizeOf aMallocSizeOf) const
1.141 +{
1.142 + size_t amount = AudioNode::SizeOfExcludingThis(aMallocSizeOf);
1.143 + amount += mGain->SizeOfIncludingThis(aMallocSizeOf);
1.144 + return amount;
1.145 +}
1.146 +
1.147 +size_t
1.148 +GainNode::SizeOfIncludingThis(MallocSizeOf aMallocSizeOf) const
1.149 +{
1.150 + return aMallocSizeOf(this) + SizeOfExcludingThis(aMallocSizeOf);
1.151 +}
1.152 +
1.153 +JSObject*
1.154 +GainNode::WrapObject(JSContext* aCx)
1.155 +{
1.156 + return GainNodeBinding::Wrap(aCx, this);
1.157 +}
1.158 +
1.159 +void
1.160 +GainNode::SendGainToStream(AudioNode* aNode)
1.161 +{
1.162 + GainNode* This = static_cast<GainNode*>(aNode);
1.163 + SendTimelineParameterToStream(This, GainNodeEngine::GAIN, *This->mGain);
1.164 +}
1.165 +
1.166 +}
1.167 +}
1.168 +
