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 *
8 * 1. Redistributions of source code must retain the above copyright
9 * notice, this list of conditions and the following disclaimer.
10 * 2. Redistributions in binary form must reproduce the above copyright
11 * notice, this list of conditions and the following disclaimer in the
12 * documentation and/or other materials provided with the distribution.
13 * 3. Neither the name of Apple Inc. ("Apple") nor the names of
14 * its contributors may be used to endorse or promote products derived
15 * from this software without specific prior written permission.
16 *
17 * THIS SOFTWARE IS PROVIDED BY APPLE AND ITS CONTRIBUTORS "AS IS" AND ANY
18 * EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
19 * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
20 * DISCLAIMED. IN NO EVENT SHALL APPLE OR ITS CONTRIBUTORS BE LIABLE FOR ANY
21 * DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
22 * (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
23 * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
24 * ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
25 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
26 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
27 */
28
29#include "config.h"
30
31#if ENABLE(WEB_AUDIO)
32
33#include "ReverbAccumulationBuffer.h"
34
35#include "VectorMath.h"
36
37#include <algorithm>
38
39namespace WebCore {
40
41using namespace VectorMath;
42
43ReverbAccumulationBuffer::ReverbAccumulationBuffer(size_t length)
44 : m_buffer(length)
45 , m_readIndex(0)
46 , m_readTimeFrame(0)
47{
48}
49
50void ReverbAccumulationBuffer::readAndClear(float* destination, size_t numberOfFrames)
51{
52 size_t bufferLength = m_buffer.size();
53 bool isCopySafe = m_readIndex <= bufferLength && numberOfFrames <= bufferLength;
54
55 ASSERT(isCopySafe);
56 if (!isCopySafe)
57 return;
58
59 size_t framesAvailable = bufferLength - m_readIndex;
60 size_t numberOfFrames1 = std::min(numberOfFrames, framesAvailable);
61 size_t numberOfFrames2 = numberOfFrames - numberOfFrames1;
62
63 float* source = m_buffer.data();
64 memcpy(destination, source + m_readIndex, sizeof(float) * numberOfFrames1);
65 memset(source + m_readIndex, 0, sizeof(float) * numberOfFrames1);
66
67 // Handle wrap-around if necessary
68 if (numberOfFrames2 > 0) {
69 memcpy(destination + numberOfFrames1, source, sizeof(float) * numberOfFrames2);
70 memset(source, 0, sizeof(float) * numberOfFrames2);
71 }
72
73 m_readIndex = (m_readIndex + numberOfFrames) % bufferLength;
74 m_readTimeFrame += numberOfFrames;
75}
76
77void ReverbAccumulationBuffer::updateReadIndex(int* readIndex, size_t numberOfFrames) const
78{
79 // Update caller's readIndex
80 *readIndex = (*readIndex + numberOfFrames) % m_buffer.size();
81}
82
83int ReverbAccumulationBuffer::accumulate(float* source, size_t numberOfFrames, int* readIndex, size_t delayFrames)
84{
85 size_t bufferLength = m_buffer.size();
86
87 size_t writeIndex = (*readIndex + delayFrames) % bufferLength;
88
89 // Update caller's readIndex
90 *readIndex = (*readIndex + numberOfFrames) % bufferLength;
91
92 size_t framesAvailable = bufferLength - writeIndex;
93 size_t numberOfFrames1 = std::min(numberOfFrames, framesAvailable);
94 size_t numberOfFrames2 = numberOfFrames - numberOfFrames1;
95
96 float* destination = m_buffer.data();
97
98 bool isSafe = writeIndex <= bufferLength && numberOfFrames1 + writeIndex <= bufferLength && numberOfFrames2 <= bufferLength;
99 ASSERT(isSafe);
100 if (!isSafe)
101 return 0;
102
103 vadd(source, 1, destination + writeIndex, 1, destination + writeIndex, 1, numberOfFrames1);
104
105 // Handle wrap-around if necessary
106 if (numberOfFrames2 > 0)
107 vadd(source + numberOfFrames1, 1, destination, 1, destination, 1, numberOfFrames2);
108
109 return writeIndex;
110}
111
112void ReverbAccumulationBuffer::reset()
113{
114 m_buffer.zero();
115 m_readIndex = 0;
116 m_readTimeFrame = 0;
117}
118
119} // namespace WebCore
120
121#endif // ENABLE(WEB_AUDIO)
122