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 "ReverbInputBuffer.h"
30 #include "mozilla/PodOperations.h"
31
32 using namespace mozilla;
33
34 namespace WebCore {
35
ReverbInputBuffer(size_t length)36 ReverbInputBuffer::ReverbInputBuffer(size_t length) : m_writeIndex(0) {
37 m_buffer.SetLength(length);
38 PodZero(m_buffer.Elements(), length);
39 }
40
write(const float * sourceP,size_t numberOfFrames)41 void ReverbInputBuffer::write(const float* sourceP, size_t numberOfFrames) {
42 // m_writeIndex is atomic and checked by other threads, so only touch
43 // it at the start and end.
44 size_t bufferLength = m_buffer.Length();
45 size_t index = m_writeIndex;
46 size_t newIndex = index + numberOfFrames;
47
48 MOZ_RELEASE_ASSERT(newIndex <= bufferLength);
49
50 memcpy(m_buffer.Elements() + index, sourceP, sizeof(float) * numberOfFrames);
51
52 if (newIndex >= bufferLength) {
53 newIndex = 0;
54 }
55 m_writeIndex = newIndex;
56 }
57
directReadFrom(int * readIndex,size_t numberOfFrames)58 float* ReverbInputBuffer::directReadFrom(int* readIndex,
59 size_t numberOfFrames) {
60 size_t bufferLength = m_buffer.Length();
61 bool isPointerGood = readIndex && *readIndex >= 0 &&
62 *readIndex + numberOfFrames <= bufferLength;
63 MOZ_ASSERT(isPointerGood);
64 if (!isPointerGood) {
65 // Should never happen in practice but return pointer to start of buffer
66 // (avoid crash)
67 if (readIndex) *readIndex = 0;
68 return m_buffer.Elements();
69 }
70
71 float* sourceP = m_buffer.Elements();
72 float* p = sourceP + *readIndex;
73
74 // Update readIndex
75 *readIndex = (*readIndex + numberOfFrames) % bufferLength;
76
77 return p;
78 }
79
reset()80 void ReverbInputBuffer::reset() {
81 PodZero(m_buffer.Elements(), m_buffer.Length());
82 m_writeIndex = 0;
83 }
84
85 } // namespace WebCore
86