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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 are
6  * met:
7  *
8  *     * Redistributions of source code must retain the above copyright
9  * notice, this list of conditions and the following disclaimer.
10  *     * Redistributions in binary form must reproduce the above
11  * copyright notice, this list of conditions and the following disclaimer
12  * in the documentation and/or other materials provided with the
13  * distribution.
14  *     * Neither the name of Google Inc. nor the names of its
15  * contributors may be used to endorse or promote products derived from
16  * this software without specific prior written permission.
17  *
18  * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
19  * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
20  * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
21  * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
22  * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
23  * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
24  * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
25  * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
26  * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
27  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
28  * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
29  */
30 
31 #include "config.h"
32 
33 #if ENABLE(WEB_AUDIO)
34 
35 #include "platform/audio/AudioDSPKernelProcessor.h"
36 
37 #include "platform/audio/AudioDSPKernel.h"
38 #include "wtf/MainThread.h"
39 
40 namespace WebCore {
41 
42 // setNumberOfChannels() may later be called if the object is not yet in an "initialized" state.
AudioDSPKernelProcessor(float sampleRate,unsigned numberOfChannels)43 AudioDSPKernelProcessor::AudioDSPKernelProcessor(float sampleRate, unsigned numberOfChannels)
44     : AudioProcessor(sampleRate, numberOfChannels)
45     , m_hasJustReset(true)
46 {
47 }
48 
initialize()49 void AudioDSPKernelProcessor::initialize()
50 {
51     if (isInitialized())
52         return;
53 
54     MutexLocker locker(m_processLock);
55     ASSERT(!m_kernels.size());
56 
57     // Create processing kernels, one per channel.
58     for (unsigned i = 0; i < numberOfChannels(); ++i)
59         m_kernels.append(createKernel());
60 
61     m_initialized = true;
62     m_hasJustReset = true;
63 }
64 
uninitialize()65 void AudioDSPKernelProcessor::uninitialize()
66 {
67     if (!isInitialized())
68         return;
69 
70     MutexLocker locker(m_processLock);
71     m_kernels.clear();
72 
73     m_initialized = false;
74 }
75 
process(const AudioBus * source,AudioBus * destination,size_t framesToProcess)76 void AudioDSPKernelProcessor::process(const AudioBus* source, AudioBus* destination, size_t framesToProcess)
77 {
78     ASSERT(source && destination);
79     if (!source || !destination)
80         return;
81 
82     if (!isInitialized()) {
83         destination->zero();
84         return;
85     }
86 
87     MutexTryLocker tryLocker(m_processLock);
88     if (tryLocker.locked()) {
89         bool channelCountMatches = source->numberOfChannels() == destination->numberOfChannels() && source->numberOfChannels() == m_kernels.size();
90         ASSERT(channelCountMatches);
91         if (!channelCountMatches)
92             return;
93 
94         for (unsigned i = 0; i < m_kernels.size(); ++i)
95             m_kernels[i]->process(source->channel(i)->data(), destination->channel(i)->mutableData(), framesToProcess);
96     } else {
97         // Unfortunately, the kernel is being processed by another thread.
98         // See also ConvolverNode::process().
99         destination->zero();
100     }
101 }
102 
103 // Resets filter state
reset()104 void AudioDSPKernelProcessor::reset()
105 {
106     ASSERT(isMainThread());
107     if (!isInitialized())
108         return;
109 
110     // Forces snap to parameter values - first time.
111     // Any processing depending on this value must set it to false at the appropriate time.
112     m_hasJustReset = true;
113 
114     MutexLocker locker(m_processLock);
115     for (unsigned i = 0; i < m_kernels.size(); ++i)
116         m_kernels[i]->reset();
117 }
118 
setNumberOfChannels(unsigned numberOfChannels)119 void AudioDSPKernelProcessor::setNumberOfChannels(unsigned numberOfChannels)
120 {
121     if (numberOfChannels == m_numberOfChannels)
122         return;
123 
124     ASSERT(!isInitialized());
125     if (!isInitialized())
126         m_numberOfChannels = numberOfChannels;
127 }
128 
tailTime() const129 double AudioDSPKernelProcessor::tailTime() const
130 {
131     ASSERT(!isMainThread());
132     MutexTryLocker tryLocker(m_processLock);
133     if (tryLocker.locked()) {
134         // It is expected that all the kernels have the same tailTime.
135         return !m_kernels.isEmpty() ? m_kernels.first()->tailTime() : 0;
136     }
137     // Since we don't want to block the Audio Device thread, we return a large value
138     // instead of trying to acquire the lock.
139     return std::numeric_limits<double>::infinity();
140 }
141 
latencyTime() const142 double AudioDSPKernelProcessor::latencyTime() const
143 {
144     ASSERT(!isMainThread());
145     MutexTryLocker tryLocker(m_processLock);
146     if (tryLocker.locked()) {
147         // It is expected that all the kernels have the same latencyTime.
148         return !m_kernels.isEmpty() ? m_kernels.first()->latencyTime() : 0;
149     }
150     // Since we don't want to block the Audio Device thread, we return a large value
151     // instead of trying to acquire the lock.
152     return std::numeric_limits<double>::infinity();
153 }
154 
155 } // namespace WebCore
156 
157 #endif // ENABLE(WEB_AUDIO)
158