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 "platform/audio/AudioChannel.h"
34
35 #include <math.h>
36 #include <algorithm>
37 #include "platform/audio/VectorMath.h"
38 #include "wtf/OwnPtr.h"
39
40 namespace WebCore {
41
42 using namespace VectorMath;
43
resizeSmaller(size_t newLength)44 void AudioChannel::resizeSmaller(size_t newLength)
45 {
46 ASSERT(newLength <= m_length);
47 if (newLength <= m_length)
48 m_length = newLength;
49 }
50
scale(float scale)51 void AudioChannel::scale(float scale)
52 {
53 if (isSilent())
54 return;
55
56 vsmul(data(), 1, &scale, mutableData(), 1, length());
57 }
58
copyFrom(const AudioChannel * sourceChannel)59 void AudioChannel::copyFrom(const AudioChannel* sourceChannel)
60 {
61 bool isSafe = (sourceChannel && sourceChannel->length() >= length());
62 ASSERT(isSafe);
63 if (!isSafe)
64 return;
65
66 if (sourceChannel->isSilent()) {
67 zero();
68 return;
69 }
70 memcpy(mutableData(), sourceChannel->data(), sizeof(float) * length());
71 }
72
copyFromRange(const AudioChannel * sourceChannel,unsigned startFrame,unsigned endFrame)73 void AudioChannel::copyFromRange(const AudioChannel* sourceChannel, unsigned startFrame, unsigned endFrame)
74 {
75 // Check that range is safe for reading from sourceChannel.
76 bool isRangeSafe = sourceChannel && startFrame < endFrame && endFrame <= sourceChannel->length();
77 ASSERT(isRangeSafe);
78 if (!isRangeSafe)
79 return;
80
81 if (sourceChannel->isSilent() && isSilent())
82 return;
83
84 // Check that this channel has enough space.
85 size_t rangeLength = endFrame - startFrame;
86 bool isRangeLengthSafe = rangeLength <= length();
87 ASSERT(isRangeLengthSafe);
88 if (!isRangeLengthSafe)
89 return;
90
91 const float* source = sourceChannel->data();
92 float* destination = mutableData();
93
94 if (sourceChannel->isSilent()) {
95 if (rangeLength == length())
96 zero();
97 else
98 memset(destination, 0, sizeof(float) * rangeLength);
99 } else
100 memcpy(destination, source + startFrame, sizeof(float) * rangeLength);
101 }
102
sumFrom(const AudioChannel * sourceChannel)103 void AudioChannel::sumFrom(const AudioChannel* sourceChannel)
104 {
105 bool isSafe = sourceChannel && sourceChannel->length() >= length();
106 ASSERT(isSafe);
107 if (!isSafe)
108 return;
109
110 if (sourceChannel->isSilent())
111 return;
112
113 if (isSilent())
114 copyFrom(sourceChannel);
115 else
116 vadd(data(), 1, sourceChannel->data(), 1, mutableData(), 1, length());
117 }
118
maxAbsValue() const119 float AudioChannel::maxAbsValue() const
120 {
121 if (isSilent())
122 return 0;
123
124 float max = 0;
125
126 vmaxmgv(data(), 1, &max, length());
127
128 return max;
129 }
130
131 } // WebCore
132
133 #endif // ENABLE(WEB_AUDIO)
134