Home | History | Annotate | Download | only in webaudio
      1 /*
      2  * Copyright (C) 2010, Google Inc. All rights reserved.
      3  *
      4  * Redistribution and use in source and binary forms, with or without
      5  * modification, are permitted provided that the following conditions
      6  * are met:
      7  * 1.  Redistributions of source code must retain the above copyright
      8  *    notice, this list of conditions and the following disclaimer.
      9  * 2.  Redistributions in binary form must reproduce the above copyright
     10  *    notice, this list of conditions and the following disclaimer in the
     11  *    documentation and/or other materials provided with the distribution.
     12  *
     13  * THIS SOFTWARE IS PROVIDED BY APPLE INC. AND ITS CONTRIBUTORS ``AS IS'' AND ANY
     14  * EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
     15  * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
     16  * DISCLAIMED. IN NO EVENT SHALL APPLE INC. OR ITS CONTRIBUTORS BE LIABLE FOR ANY
     17  * DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
     18  * (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
     19  * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON
     20  * ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
     21  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
     22  * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
     23  */
     24 
     25 #include "config.h"
     26 
     27 #if ENABLE(WEB_AUDIO)
     28 
     29 #include "modules/webaudio/AudioNodeOutput.h"
     30 
     31 #include "modules/webaudio/AudioContext.h"
     32 #include "modules/webaudio/AudioNodeInput.h"
     33 #include "wtf/Threading.h"
     34 
     35 namespace WebCore {
     36 
     37 AudioNodeOutput::AudioNodeOutput(AudioNode* node, unsigned numberOfChannels)
     38     : m_node(node)
     39     , m_numberOfChannels(numberOfChannels)
     40     , m_desiredNumberOfChannels(numberOfChannels)
     41     , m_isInPlace(false)
     42     , m_isEnabled(true)
     43     , m_renderingFanOutCount(0)
     44     , m_renderingParamFanOutCount(0)
     45 {
     46     ASSERT(numberOfChannels <= AudioContext::maxNumberOfChannels());
     47 
     48     m_internalBus = AudioBus::create(numberOfChannels, AudioNode::ProcessingSizeInFrames);
     49 }
     50 
     51 void AudioNodeOutput::setNumberOfChannels(unsigned numberOfChannels)
     52 {
     53     ASSERT(numberOfChannels <= AudioContext::maxNumberOfChannels());
     54     ASSERT(context()->isGraphOwner());
     55 
     56     m_desiredNumberOfChannels = numberOfChannels;
     57 
     58     if (context()->isAudioThread()) {
     59         // If we're in the audio thread then we can take care of it right away (we should be at the very start or end of a rendering quantum).
     60         updateNumberOfChannels();
     61     } else {
     62         // Let the context take care of it in the audio thread in the pre and post render tasks.
     63         context()->markAudioNodeOutputDirty(this);
     64     }
     65 }
     66 
     67 void AudioNodeOutput::updateInternalBus()
     68 {
     69     if (numberOfChannels() == m_internalBus->numberOfChannels())
     70         return;
     71 
     72     m_internalBus = AudioBus::create(numberOfChannels(), AudioNode::ProcessingSizeInFrames);
     73 }
     74 
     75 void AudioNodeOutput::updateRenderingState()
     76 {
     77     updateNumberOfChannels();
     78     m_renderingFanOutCount = fanOutCount();
     79     m_renderingParamFanOutCount = paramFanOutCount();
     80 }
     81 
     82 void AudioNodeOutput::updateNumberOfChannels()
     83 {
     84     ASSERT(context()->isAudioThread() && context()->isGraphOwner());
     85 
     86     if (m_numberOfChannels != m_desiredNumberOfChannels) {
     87         m_numberOfChannels = m_desiredNumberOfChannels;
     88         updateInternalBus();
     89         propagateChannelCount();
     90     }
     91 }
     92 
     93 void AudioNodeOutput::propagateChannelCount()
     94 {
     95     ASSERT(context()->isAudioThread() && context()->isGraphOwner());
     96 
     97     if (isChannelCountKnown()) {
     98         // Announce to any nodes we're connected to that we changed our channel count for its input.
     99         for (InputsIterator i = m_inputs.begin(); i != m_inputs.end(); ++i) {
    100             AudioNodeInput* input = *i;
    101             AudioNode* connectionNode = input->node();
    102             connectionNode->checkNumberOfChannelsForInput(input);
    103         }
    104     }
    105 }
    106 
    107 AudioBus* AudioNodeOutput::pull(AudioBus* inPlaceBus, size_t framesToProcess)
    108 {
    109     ASSERT(context()->isAudioThread());
    110     ASSERT(m_renderingFanOutCount > 0 || m_renderingParamFanOutCount > 0);
    111 
    112     // Causes our AudioNode to process if it hasn't already for this render quantum.
    113     // We try to do in-place processing (using inPlaceBus) if at all possible,
    114     // but we can't process in-place if we're connected to more than one input (fan-out > 1).
    115     // In this case pull() is called multiple times per rendering quantum, and the processIfNecessary() call below will
    116     // cause our node to process() only the first time, caching the output in m_internalOutputBus for subsequent calls.
    117 
    118     m_isInPlace = inPlaceBus && inPlaceBus->numberOfChannels() == numberOfChannels() && (m_renderingFanOutCount + m_renderingParamFanOutCount) == 1;
    119 
    120     m_inPlaceBus = m_isInPlace ? inPlaceBus : 0;
    121 
    122     node()->processIfNecessary(framesToProcess);
    123     return bus();
    124 }
    125 
    126 AudioBus* AudioNodeOutput::bus() const
    127 {
    128     ASSERT(const_cast<AudioNodeOutput*>(this)->context()->isAudioThread());
    129     return m_isInPlace ? m_inPlaceBus.get() : m_internalBus.get();
    130 }
    131 
    132 unsigned AudioNodeOutput::fanOutCount()
    133 {
    134     ASSERT(context()->isGraphOwner());
    135     return m_inputs.size();
    136 }
    137 
    138 unsigned AudioNodeOutput::paramFanOutCount()
    139 {
    140     ASSERT(context()->isGraphOwner());
    141     return m_params.size();
    142 }
    143 
    144 unsigned AudioNodeOutput::renderingFanOutCount() const
    145 {
    146     return m_renderingFanOutCount;
    147 }
    148 
    149 unsigned AudioNodeOutput::renderingParamFanOutCount() const
    150 {
    151     return m_renderingParamFanOutCount;
    152 }
    153 
    154 void AudioNodeOutput::addInput(AudioNodeInput* input)
    155 {
    156     ASSERT(context()->isGraphOwner());
    157 
    158     ASSERT(input);
    159     if (!input)
    160         return;
    161 
    162     m_inputs.add(input);
    163 }
    164 
    165 void AudioNodeOutput::removeInput(AudioNodeInput* input)
    166 {
    167     ASSERT(context()->isGraphOwner());
    168 
    169     ASSERT(input);
    170     if (!input)
    171         return;
    172 
    173     m_inputs.remove(input);
    174 }
    175 
    176 void AudioNodeOutput::disconnectAllInputs()
    177 {
    178     ASSERT(context()->isGraphOwner());
    179 
    180     // AudioNodeInput::disconnect() changes m_inputs by calling removeInput().
    181     while (!m_inputs.isEmpty()) {
    182         AudioNodeInput* input = *m_inputs.begin();
    183         input->disconnect(this);
    184     }
    185 }
    186 
    187 void AudioNodeOutput::addParam(AudioParam* param)
    188 {
    189     ASSERT(context()->isGraphOwner());
    190 
    191     ASSERT(param);
    192     if (!param)
    193         return;
    194 
    195     m_params.add(param);
    196 }
    197 
    198 void AudioNodeOutput::removeParam(AudioParam* param)
    199 {
    200     ASSERT(context()->isGraphOwner());
    201 
    202     ASSERT(param);
    203     if (!param)
    204         return;
    205 
    206     m_params.remove(param);
    207 }
    208 
    209 void AudioNodeOutput::disconnectAllParams()
    210 {
    211     ASSERT(context()->isGraphOwner());
    212 
    213     // AudioParam::disconnect() changes m_params by calling removeParam().
    214     while (!m_params.isEmpty()) {
    215         AudioParam* param = m_params.begin()->get();
    216         param->disconnect(this);
    217     }
    218 }
    219 
    220 void AudioNodeOutput::disconnectAll()
    221 {
    222     disconnectAllInputs();
    223     disconnectAllParams();
    224 }
    225 
    226 void AudioNodeOutput::disable()
    227 {
    228     ASSERT(context()->isGraphOwner());
    229 
    230     if (m_isEnabled) {
    231         for (InputsIterator i = m_inputs.begin(); i != m_inputs.end(); ++i) {
    232             AudioNodeInput* input = *i;
    233             input->disable(this);
    234         }
    235         m_isEnabled = false;
    236     }
    237 }
    238 
    239 void AudioNodeOutput::enable()
    240 {
    241     ASSERT(context()->isGraphOwner());
    242 
    243     if (!m_isEnabled) {
    244         for (InputsIterator i = m_inputs.begin(); i != m_inputs.end(); ++i) {
    245             AudioNodeInput* input = *i;
    246             input->enable(this);
    247         }
    248         m_isEnabled = true;
    249     }
    250 }
    251 
    252 } // namespace WebCore
    253 
    254 #endif // ENABLE(WEB_AUDIO)
    255