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/DelayDSPKernel.h"
30
31#include "platform/audio/AudioUtilities.h"
32#include "wtf/MathExtras.h"
33#include <algorithm>
34
35namespace blink {
36
37const float SmoothingTimeConstant = 0.020f; // 20ms
38
39DelayDSPKernel::DelayDSPKernel(DelayProcessor* processor)
40    : AudioDelayDSPKernel(processor, AudioNode::ProcessingSizeInFrames)
41{
42    ASSERT(processor && processor->sampleRate() > 0);
43    if (!(processor && processor->sampleRate() > 0))
44        return;
45
46    m_maxDelayTime = processor->maxDelayTime();
47    ASSERT(m_maxDelayTime >= 0 && !std::isnan(m_maxDelayTime));
48    if (m_maxDelayTime < 0 || std::isnan(m_maxDelayTime))
49        return;
50
51    m_buffer.allocate(bufferLengthForDelay(m_maxDelayTime, processor->sampleRate()));
52    m_buffer.zero();
53
54    m_smoothingRate = AudioUtilities::discreteTimeConstantForSampleRate(SmoothingTimeConstant, processor->sampleRate());
55}
56
57bool DelayDSPKernel::hasSampleAccurateValues()
58{
59    return delayProcessor()->delayTime()->hasSampleAccurateValues();
60}
61
62void DelayDSPKernel::calculateSampleAccurateValues(float* delayTimes, size_t framesToProcess)
63{
64    delayProcessor()->delayTime()->calculateSampleAccurateValues(delayTimes, framesToProcess);
65}
66
67double DelayDSPKernel::delayTime(float)
68{
69    return delayProcessor()->delayTime()->finalValue();
70}
71
72} // namespace blink
73
74#endif // ENABLE(WEB_AUDIO)
75