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 "AudioChannel.h"
34
35#include "VectorMath.h"
36#include <algorithm>
37#include <math.h>
38
39namespace WebCore {
40
41using namespace VectorMath;
42
43void AudioChannel::resizeSmaller(size_t newLength)
44{
45    ASSERT(newLength <= m_length);
46    if (newLength <= m_length)
47        m_length = newLength;
48}
49
50void AudioChannel::scale(float scale)
51{
52    if (isSilent())
53        return;
54
55    vsmul(data(), 1, &scale, mutableData(), 1, length());
56}
57
58void AudioChannel::copyFrom(const AudioChannel* sourceChannel)
59{
60    bool isSafe = (sourceChannel && sourceChannel->length() >= length());
61    ASSERT(isSafe);
62    if (!isSafe)
63        return;
64
65    if (sourceChannel->isSilent()) {
66        zero();
67        return;
68    }
69    memcpy(mutableData(), sourceChannel->data(), sizeof(float) * length());
70}
71
72void AudioChannel::copyFromRange(const AudioChannel* sourceChannel, unsigned startFrame, unsigned endFrame)
73{
74    // Check that range is safe for reading from sourceChannel.
75    bool isRangeSafe = sourceChannel && startFrame < endFrame && endFrame <= sourceChannel->length();
76    ASSERT(isRangeSafe);
77    if (!isRangeSafe)
78        return;
79
80    if (sourceChannel->isSilent() && isSilent())
81        return;
82
83    // Check that this channel has enough space.
84    size_t rangeLength = endFrame - startFrame;
85    bool isRangeLengthSafe = rangeLength <= length();
86    ASSERT(isRangeLengthSafe);
87    if (!isRangeLengthSafe)
88        return;
89
90    const float* source = sourceChannel->data();
91    float* destination = mutableData();
92
93    if (sourceChannel->isSilent()) {
94        if (rangeLength == length())
95            zero();
96        else
97            memset(destination, 0, sizeof(float) * rangeLength);
98    } else
99        memcpy(destination, source + startFrame, sizeof(float) * rangeLength);
100}
101
102void AudioChannel::sumFrom(const AudioChannel* sourceChannel)
103{
104    bool isSafe = sourceChannel && sourceChannel->length() >= length();
105    ASSERT(isSafe);
106    if (!isSafe)
107        return;
108
109    if (sourceChannel->isSilent())
110        return;
111
112    if (isSilent())
113        copyFrom(sourceChannel);
114    else
115        vadd(data(), 1, sourceChannel->data(), 1, mutableData(), 1, length());
116}
117
118float AudioChannel::maxAbsValue() const
119{
120    if (isSilent())
121        return 0;
122
123    float max = 0;
124
125    vmaxmgv(data(), 1, &max, length());
126
127    return max;
128}
129
130} // WebCore
131
132#endif // ENABLE(WEB_AUDIO)
133