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 Computer, 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 namespace WebCore {
38
39 using namespace VectorMath;
40
ReverbAccumulationBuffer(size_t length)41 ReverbAccumulationBuffer::ReverbAccumulationBuffer(size_t length)
42 : m_buffer(length)
43 , m_readIndex(0)
44 , m_readTimeFrame(0)
45 {
46 }
47
readAndClear(float * destination,size_t numberOfFrames)48 void ReverbAccumulationBuffer::readAndClear(float* destination, size_t numberOfFrames)
49 {
50 size_t bufferLength = m_buffer.size();
51 bool isCopySafe = m_readIndex <= bufferLength && numberOfFrames <= bufferLength;
52
53 ASSERT(isCopySafe);
54 if (!isCopySafe)
55 return;
56
57 size_t framesAvailable = bufferLength - m_readIndex;
58 size_t numberOfFrames1 = std::min(numberOfFrames, framesAvailable);
59 size_t numberOfFrames2 = numberOfFrames - numberOfFrames1;
60
61 float* source = m_buffer.data();
62 memcpy(destination, source + m_readIndex, sizeof(float) * numberOfFrames1);
63 memset(source + m_readIndex, 0, sizeof(float) * numberOfFrames1);
64
65 // Handle wrap-around if necessary
66 if (numberOfFrames2 > 0) {
67 memcpy(destination + numberOfFrames1, source, sizeof(float) * numberOfFrames2);
68 memset(source, 0, sizeof(float) * numberOfFrames2);
69 }
70
71 m_readIndex = (m_readIndex + numberOfFrames) % bufferLength;
72 m_readTimeFrame += numberOfFrames;
73 }
74
updateReadIndex(int * readIndex,size_t numberOfFrames) const75 void ReverbAccumulationBuffer::updateReadIndex(int* readIndex, size_t numberOfFrames) const
76 {
77 // Update caller's readIndex
78 *readIndex = (*readIndex + numberOfFrames) % m_buffer.size();
79 }
80
accumulate(float * source,size_t numberOfFrames,int * readIndex,size_t delayFrames)81 int ReverbAccumulationBuffer::accumulate(float* source, size_t numberOfFrames, int* readIndex, size_t delayFrames)
82 {
83 size_t bufferLength = m_buffer.size();
84
85 size_t writeIndex = (*readIndex + delayFrames) % bufferLength;
86
87 // Update caller's readIndex
88 *readIndex = (*readIndex + numberOfFrames) % bufferLength;
89
90 size_t framesAvailable = bufferLength - writeIndex;
91 size_t numberOfFrames1 = std::min(numberOfFrames, framesAvailable);
92 size_t numberOfFrames2 = numberOfFrames - numberOfFrames1;
93
94 float* destination = m_buffer.data();
95
96 bool isSafe = writeIndex <= bufferLength && numberOfFrames1 + writeIndex <= bufferLength && numberOfFrames2 <= bufferLength;
97 ASSERT(isSafe);
98 if (!isSafe)
99 return 0;
100
101 vadd(source, 1, destination + writeIndex, 1, destination + writeIndex, 1, numberOfFrames1);
102
103 // Handle wrap-around if necessary
104 if (numberOfFrames2 > 0)
105 vadd(source + numberOfFrames1, 1, destination, 1, destination, 1, numberOfFrames2);
106
107 return writeIndex;
108 }
109
reset()110 void ReverbAccumulationBuffer::reset()
111 {
112 m_buffer.zero();
113 m_readIndex = 0;
114 m_readTimeFrame = 0;
115 }
116
117 } // namespace WebCore
118
119 #endif // ENABLE(WEB_AUDIO)
120