Home | History | Annotate | Download | only in webaudio 
      1 /*
      2  * Copyright (C) 2012, Intel Corporation. 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/AudioBasicInspectorNode.h"
     30 
     31 #include "modules/webaudio/AudioContext.h"
     32 #include "modules/webaudio/AudioNodeInput.h"
     33 #include "modules/webaudio/AudioNodeOutput.h"
     34 
     35 namespace WebCore {
     36 
     37 AudioBasicInspectorNode::AudioBasicInspectorNode(AudioContext* context, float sampleRate, unsigned outputChannelCount)
     38     : AudioNode(context, sampleRate)
     39     , m_needAutomaticPull(false)
     40 {
     41     addInput(adoptPtr(new AudioNodeInput(this)));
     42     addOutput(adoptPtr(new AudioNodeOutput(this, outputChannelCount)));
     43 }
     44 
     45 // We override pullInputs() as an optimization allowing this node to take advantage of in-place processing,
     46 // where the input is simply passed through unprocessed to the output.
     47 // Note: this only applies if the input and output channel counts match.
     48 void AudioBasicInspectorNode::pullInputs(size_t framesToProcess)
     49 {
     50     // Render input stream - try to render directly into output bus for pass-through processing where process() doesn't need to do anything...
     51     input(0)->pull(output(0)->bus(), framesToProcess);
     52 }
     53 
     54 void AudioBasicInspectorNode::connect(AudioNode* destination, unsigned outputIndex, unsigned inputIndex, ExceptionState& es)
     55 {
     56     ASSERT(isMainThread());
     57 
     58     AudioContext::AutoLocker locker(context());
     59 
     60     AudioNode::connect(destination, outputIndex, inputIndex, es);
     61     updatePullStatus();
     62 }
     63 
     64 void AudioBasicInspectorNode::disconnect(unsigned outputIndex, ExceptionState& es)
     65 {
     66     ASSERT(isMainThread());
     67 
     68     AudioContext::AutoLocker locker(context());
     69 
     70     AudioNode::disconnect(outputIndex, es);
     71     updatePullStatus();
     72 }
     73 
     74 void AudioBasicInspectorNode::checkNumberOfChannelsForInput(AudioNodeInput* input)
     75 {
     76     ASSERT(context()->isAudioThread() && context()->isGraphOwner());
     77 
     78     ASSERT(input == this->input(0));
     79     if (input != this->input(0))
     80         return;
     81 
     82     unsigned numberOfChannels = input->numberOfChannels();
     83 
     84     if (numberOfChannels != output(0)->numberOfChannels()) {
     85         // This will propagate the channel count to any nodes connected further downstream in the graph.
     86         output(0)->setNumberOfChannels(numberOfChannels);
     87     }
     88 
     89     AudioNode::checkNumberOfChannelsForInput(input);
     90 
     91     updatePullStatus();
     92 }
     93 
     94 void AudioBasicInspectorNode::updatePullStatus()
     95 {
     96     ASSERT(context()->isGraphOwner());
     97 
     98     if (output(0)->isConnected()) {
     99         // When an AudioBasicInspectorNode is connected to a downstream node, it will get pulled by the
    100         // downstream node, thus remove it from the context's automatic pull list.
    101         if (m_needAutomaticPull) {
    102             context()->removeAutomaticPullNode(this);
    103             m_needAutomaticPull = false;
    104         }
    105     } else {
    106         unsigned numberOfInputConnections = input(0)->numberOfRenderingConnections();
    107         if (numberOfInputConnections && !m_needAutomaticPull) {
    108             // When an AudioBasicInspectorNode is not connected to any downstream node while still connected from
    109             // upstream node(s), add it to the context's automatic pull list.
    110             context()->addAutomaticPullNode(this);
    111             m_needAutomaticPull = true;
    112         } else if (!numberOfInputConnections && m_needAutomaticPull) {
    113             // The AudioBasicInspectorNode is connected to nothing, remove it from the context's automatic pull list.
    114             context()->removeAutomaticPullNode(this);
    115             m_needAutomaticPull = false;
    116         }
    117     }
    118 }
    119 
    120 } // namespace WebCore
    121 
    122 #endif // ENABLE(WEB_AUDIO)
    123