The Tor Browser: content/media/webaudio/AudioParam.cpp@6474c204b198

Cloned upstream origin tor-browser at tor-browser-31.3.0esr-4.5-1-build1
revision ID fc1c9ff7c1b2defdbc039f12214767608f46423f for hacking purpose.

     1 /* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- */

     2 /* vim:set ts=2 sw=2 sts=2 et cindent: */

     3 /* This Source Code Form is subject to the terms of the Mozilla Public

     4  * License, v. 2.0. If a copy of the MPL was not distributed with this

     5  * file, You can obtain one at http://mozilla.org/MPL/2.0/. */

     7 #include "AudioParam.h"

     8 #include "mozilla/dom/AudioParamBinding.h"

     9 #include "AudioNodeEngine.h"

    10 #include "AudioNodeStream.h"

    11 #include "AudioContext.h"

    13 namespace mozilla {

    14 namespace dom {

    16 NS_IMPL_CYCLE_COLLECTION_CLASS(AudioParam)

    18 NS_IMPL_CYCLE_COLLECTION_UNLINK_BEGIN(AudioParam)

    19   tmp->DisconnectFromGraphAndDestroyStream();

    20   NS_IMPL_CYCLE_COLLECTION_UNLINK(mNode)

    21   NS_IMPL_CYCLE_COLLECTION_UNLINK_PRESERVED_WRAPPER

    22 NS_IMPL_CYCLE_COLLECTION_UNLINK_END

    23 NS_IMPL_CYCLE_COLLECTION_TRAVERSE_BEGIN(AudioParam)

    24   NS_IMPL_CYCLE_COLLECTION_TRAVERSE(mNode)

    25   NS_IMPL_CYCLE_COLLECTION_TRAVERSE_SCRIPT_OBJECTS

    26 NS_IMPL_CYCLE_COLLECTION_TRAVERSE_END

    28 NS_IMPL_CYCLE_COLLECTION_TRACE_WRAPPERCACHE(AudioParam)

    30 NS_IMPL_CYCLE_COLLECTING_NATIVE_ADDREF(AudioParam)

    32 NS_IMETHODIMP_(MozExternalRefCountType)

    33 AudioParam::Release()

    34 {

    35   if (mRefCnt.get() == 1) {

    36     // We are about to be deleted, disconnect the object from the graph before

    37     // the derived type is destroyed.

    38     DisconnectFromGraphAndDestroyStream();

    39   }

    40   NS_IMPL_CC_NATIVE_RELEASE_BODY(AudioParam)

    41 }

    43 NS_IMPL_CYCLE_COLLECTION_ROOT_NATIVE(AudioParam, AddRef)

    44 NS_IMPL_CYCLE_COLLECTION_UNROOT_NATIVE(AudioParam, Release)

    46 AudioParam::AudioParam(AudioNode* aNode,

    47                        AudioParam::CallbackType aCallback,

    48                        float aDefaultValue)

    49   : AudioParamTimeline(aDefaultValue)

    50   , mNode(aNode)

    51   , mCallback(aCallback)

    52   , mDefaultValue(aDefaultValue)

    53 {

    54   SetIsDOMBinding();

    55 }

    57 AudioParam::~AudioParam()

    58 {

    59   MOZ_ASSERT(mInputNodes.IsEmpty());

    60 }

    62 JSObject*

    63 AudioParam::WrapObject(JSContext* aCx)

    64 {

    65   return AudioParamBinding::Wrap(aCx, this);

    66 }

    68 void

    69 AudioParam::DisconnectFromGraphAndDestroyStream()

    70 {

    71   // Addref this temporarily so the refcount bumping below doesn't destroy us

    72   // prematurely

    73   nsRefPtr<AudioParam> kungFuDeathGrip = this;

    75   while (!mInputNodes.IsEmpty()) {

    76     uint32_t i = mInputNodes.Length() - 1;

    77     nsRefPtr<AudioNode> input = mInputNodes[i].mInputNode;

    78     mInputNodes.RemoveElementAt(i);

    79     input->RemoveOutputParam(this);

    80   }

    82   if (mNodeStreamPort) {

    83     mNodeStreamPort->Destroy();

    84     mNodeStreamPort = nullptr;

    85   }

    87   if (mStream) {

    88     mStream->Destroy();

    89     mStream = nullptr;

    90   }

    91 }

    93 MediaStream*

    94 AudioParam::Stream()

    95 {

    96   if (mStream) {

    97     return mStream;

    98   }

   100   AudioNodeEngine* engine = new AudioNodeEngine(nullptr);

   101   nsRefPtr<AudioNodeStream> stream =

   102     mNode->Context()->Graph()->CreateAudioNodeStream(engine,

   103                                                      MediaStreamGraph::INTERNAL_STREAM,

   104                                                      Node()->Context()->SampleRate());

   106   // Force the input to have only one channel, and make it down-mix using

   107   // the speaker rules if needed.

   108   stream->SetChannelMixingParametersImpl(1, ChannelCountMode::Explicit, ChannelInterpretation::Speakers);

   109   // Mark as an AudioParam helper stream

   110   stream->SetAudioParamHelperStream();

   112   mStream = stream.forget();

   114   // Setup the AudioParam's stream as an input to the owner AudioNode's stream

   115   MediaStream* nodeStream = mNode->Stream();

   116   MOZ_ASSERT(nodeStream->AsProcessedStream());

   117   ProcessedMediaStream* ps = static_cast<ProcessedMediaStream*>(nodeStream);

   118   mNodeStreamPort = ps->AllocateInputPort(mStream, MediaInputPort::FLAG_BLOCK_INPUT);

   120   // Let the MSG's copy of AudioParamTimeline know about the change in the stream

   121   mCallback(mNode);

   123   return mStream;

   124 }

   126 float

   127 AudioParamTimeline::AudioNodeInputValue(size_t aCounter) const

   128 {

   129   MOZ_ASSERT(mStream);

   131   // If we have a chunk produced by the AudioNode inputs to the AudioParam,

   132   // get its value now.  We use aCounter to tell us which frame of the last

   133   // AudioChunk to look at.

   134   float audioNodeInputValue = 0.0f;

   135   const AudioChunk& lastAudioNodeChunk =

   136     static_cast<AudioNodeStream*>(mStream.get())->LastChunks()[0];

   137   if (!lastAudioNodeChunk.IsNull()) {

   138     MOZ_ASSERT(lastAudioNodeChunk.GetDuration() == WEBAUDIO_BLOCK_SIZE);

   139     audioNodeInputValue =

   140       static_cast<const float*>(lastAudioNodeChunk.mChannelData[0])[aCounter];

   141     audioNodeInputValue *= lastAudioNodeChunk.mVolume;

   142   }

   144   return audioNodeInputValue;

   145 }

   147 }

   148 }

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