1/*
2 * Copyright (C) 2011, 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 * 1. Redistributions of source code must retain the above copyright
8 * notice, this list of conditions and the following disclaimer.
9 * 2. Redistributions in binary form must reproduce the above copyright
10 * notice, this list of conditions and the following disclaimer in the
11 * documentation and/or other materials provided with the distribution.
12 *
13 * THIS SOFTWARE IS PROVIDED BY APPLE INC. AND ITS CONTRIBUTORS ``AS IS'' AND ANY
14 * EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
15 * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
16 * DISCLAIMED. IN NO EVENT SHALL APPLE INC. OR ITS CONTRIBUTORS BE LIABLE FOR ANY
17 * DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
18 * (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
19 * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON
20 * ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
21 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
22 * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
23 */
24
25#include "config.h"
26
27#if ENABLE(WEB_AUDIO) && ENABLE(VIDEO)
28
29#include "MediaElementAudioSourceNode.h"
30
31#include "AudioContext.h"
32#include "AudioNodeOutput.h"
33#include "Logging.h"
34#include "MediaPlayer.h"
35#include <wtf/IsoMallocInlines.h>
36#include <wtf/Locker.h>
37
38// These are somewhat arbitrary limits, but we need to do some kind of sanity-checking.
39const unsigned minSampleRate = 8000;
40const unsigned maxSampleRate = 192000;
41
42namespace WebCore {
43
44WTF_MAKE_ISO_ALLOCATED_IMPL(MediaElementAudioSourceNode);
45
46Ref<MediaElementAudioSourceNode> MediaElementAudioSourceNode::create(AudioContext& context, HTMLMediaElement& mediaElement)
47{
48 return adoptRef(*new MediaElementAudioSourceNode(context, mediaElement));
49}
50
51MediaElementAudioSourceNode::MediaElementAudioSourceNode(AudioContext& context, HTMLMediaElement& mediaElement)
52 : AudioNode(context, context.sampleRate())
53 , m_mediaElement(mediaElement)
54 , m_sourceNumberOfChannels(0)
55 , m_sourceSampleRate(0)
56{
57 setNodeType(NodeTypeMediaElementAudioSource);
58
59 // Default to stereo. This could change depending on what the media element .src is set to.
60 addOutput(std::make_unique<AudioNodeOutput>(this, 2));
61
62 initialize();
63}
64
65MediaElementAudioSourceNode::~MediaElementAudioSourceNode()
66{
67 m_mediaElement->setAudioSourceNode(nullptr);
68 uninitialize();
69}
70
71void MediaElementAudioSourceNode::setFormat(size_t numberOfChannels, float sourceSampleRate)
72{
73 m_muted = wouldTaintOrigin();
74
75 if (numberOfChannels != m_sourceNumberOfChannels || sourceSampleRate != m_sourceSampleRate) {
76 if (!numberOfChannels || numberOfChannels > AudioContext::maxNumberOfChannels() || sourceSampleRate < minSampleRate || sourceSampleRate > maxSampleRate) {
77 // process() will generate silence for these uninitialized values.
78 LOG(Media, "MediaElementAudioSourceNode::setFormat(%u, %f) - unhandled format change", static_cast<unsigned>(numberOfChannels), sourceSampleRate);
79 m_sourceNumberOfChannels = 0;
80 m_sourceSampleRate = 0;
81 return;
82 }
83
84 m_sourceNumberOfChannels = numberOfChannels;
85 m_sourceSampleRate = sourceSampleRate;
86
87 // Synchronize with process().
88 std::lock_guard<MediaElementAudioSourceNode> lock(*this);
89
90 if (sourceSampleRate != sampleRate()) {
91 double scaleFactor = sourceSampleRate / sampleRate();
92 m_multiChannelResampler = std::make_unique<MultiChannelResampler>(scaleFactor, numberOfChannels);
93 } else {
94 // Bypass resampling.
95 m_multiChannelResampler = nullptr;
96 }
97
98 {
99 // The context must be locked when changing the number of output channels.
100 AudioContext::AutoLocker contextLocker(context());
101
102 // Do any necesssary re-configuration to the output's number of channels.
103 output(0)->setNumberOfChannels(numberOfChannels);
104 }
105 }
106}
107
108bool MediaElementAudioSourceNode::wouldTaintOrigin()
109{
110 if (!m_mediaElement->hasSingleSecurityOrigin())
111 return true;
112
113 if (m_mediaElement->didPassCORSAccessCheck())
114 return false;
115
116 if (auto* origin = context().origin())
117 return m_mediaElement->wouldTaintOrigin(*origin);
118
119 return true;
120}
121
122void MediaElementAudioSourceNode::process(size_t numberOfFrames)
123{
124 AudioBus* outputBus = output(0)->bus();
125
126 if (m_muted || !m_sourceNumberOfChannels || !m_sourceSampleRate) {
127 outputBus->zero();
128 return;
129 }
130
131 // Use a std::try_to_lock to avoid contention in the real-time audio thread.
132 // If we fail to acquire the lock then the HTMLMediaElement must be in the middle of
133 // reconfiguring its playback engine, so we output silence in this case.
134 std::unique_lock<Lock> lock(m_processMutex, std::try_to_lock);
135 if (!lock.owns_lock()) {
136 // We failed to acquire the lock.
137 outputBus->zero();
138 return;
139 }
140
141 if (AudioSourceProvider* provider = mediaElement().audioSourceProvider()) {
142 if (m_multiChannelResampler.get()) {
143 ASSERT(m_sourceSampleRate != sampleRate());
144 m_multiChannelResampler->process(provider, outputBus, numberOfFrames);
145 } else {
146 // Bypass the resampler completely if the source is at the context's sample-rate.
147 ASSERT(m_sourceSampleRate == sampleRate());
148 provider->provideInput(outputBus, numberOfFrames);
149 }
150 } else {
151 // Either this port doesn't yet support HTMLMediaElement audio stream access,
152 // or the stream is not yet available.
153 outputBus->zero();
154 }
155}
156
157void MediaElementAudioSourceNode::reset()
158{
159}
160
161void MediaElementAudioSourceNode::lock()
162{
163 ref();
164 m_processMutex.lock();
165}
166
167void MediaElementAudioSourceNode::unlock()
168{
169 m_processMutex.unlock();
170 deref();
171}
172
173} // namespace WebCore
174
175#endif // ENABLE(WEB_AUDIO)
176