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 "AudioDSPKernelProcessor.h"
36
37#include "AudioDSPKernel.h"
38
39namespace WebCore {
40
41// setNumberOfChannels() may later be called if the object is not yet in an "initialized" state.
42AudioDSPKernelProcessor::AudioDSPKernelProcessor(float sampleRate, unsigned numberOfChannels)
43    : AudioProcessor(sampleRate, numberOfChannels)
44    , m_hasJustReset(true)
45{
46}
47
48void AudioDSPKernelProcessor::initialize()
49{
50    if (isInitialized())
51        return;
52
53    ASSERT(!m_kernels.size());
54
55    // Create processing kernels, one per channel.
56    for (unsigned i = 0; i < numberOfChannels(); ++i)
57        m_kernels.append(createKernel());
58
59    m_initialized = true;
60    m_hasJustReset = true;
61}
62
63void AudioDSPKernelProcessor::uninitialize()
64{
65    if (!isInitialized())
66        return;
67
68    m_kernels.clear();
69
70    m_initialized = false;
71}
72
73void AudioDSPKernelProcessor::process(const AudioBus* source, AudioBus* destination, size_t framesToProcess)
74{
75    ASSERT(source && destination);
76    if (!source || !destination)
77        return;
78
79    if (!isInitialized()) {
80        destination->zero();
81        return;
82    }
83
84    bool channelCountMatches = source->numberOfChannels() == destination->numberOfChannels() && source->numberOfChannels() == m_kernels.size();
85    ASSERT(channelCountMatches);
86    if (!channelCountMatches)
87        return;
88
89    for (unsigned i = 0; i < m_kernels.size(); ++i)
90        m_kernels[i]->process(source->channel(i)->data(), destination->channel(i)->mutableData(), framesToProcess);
91}
92
93// Resets filter state
94void AudioDSPKernelProcessor::reset()
95{
96    if (!isInitialized())
97        return;
98
99    // Forces snap to parameter values - first time.
100    // Any processing depending on this value must set it to false at the appropriate time.
101    m_hasJustReset = true;
102
103    for (unsigned i = 0; i < m_kernels.size(); ++i)
104        m_kernels[i]->reset();
105}
106
107void AudioDSPKernelProcessor::setNumberOfChannels(unsigned numberOfChannels)
108{
109    if (numberOfChannels == m_numberOfChannels)
110        return;
111
112    ASSERT(!isInitialized());
113    if (!isInitialized())
114        m_numberOfChannels = numberOfChannels;
115}
116
117double AudioDSPKernelProcessor::tailTime() const
118{
119    // It is expected that all the kernels have the same tailTime.
120    return !m_kernels.isEmpty() ? m_kernels.first()->tailTime() : 0;
121}
122
123double AudioDSPKernelProcessor::latencyTime() const
124{
125    // It is expected that all the kernels have the same latencyTime.
126    return !m_kernels.isEmpty() ? m_kernels.first()->latencyTime() : 0;
127}
128
129} // namespace WebCore
130
131#endif // ENABLE(WEB_AUDIO)
132