1 /*
2 * Copyright (C) 2012 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/AudioPullFIFO.h"
34
35 namespace blink {
36
AudioPullFIFO(AudioSourceProvider & audioProvider,unsigned numberOfChannels,size_t fifoLength,size_t providerSize)37 AudioPullFIFO::AudioPullFIFO(AudioSourceProvider& audioProvider, unsigned numberOfChannels, size_t fifoLength, size_t providerSize)
38 : m_provider(audioProvider)
39 , m_fifo(numberOfChannels, fifoLength)
40 , m_providerSize(providerSize)
41 , m_tempBus(AudioBus::create(numberOfChannels, providerSize))
42 {
43 }
44
consume(AudioBus * destination,size_t framesToConsume)45 void AudioPullFIFO::consume(AudioBus* destination, size_t framesToConsume)
46 {
47 if (!destination)
48 return;
49
50 if (framesToConsume > m_fifo.framesInFifo()) {
51 // We don't have enough data in the FIFO to fulfill the request. Ask for more data.
52 fillBuffer(framesToConsume - m_fifo.framesInFifo());
53 }
54
55 m_fifo.consume(destination, framesToConsume);
56 }
57
fillBuffer(size_t numberOfFrames)58 void AudioPullFIFO::fillBuffer(size_t numberOfFrames)
59 {
60 // Keep asking the provider to give us data until we have received at least |numberOfFrames| of
61 // data. Stuff the data into the FIFO.
62 size_t framesProvided = 0;
63
64 while (framesProvided < numberOfFrames) {
65 m_provider.provideInput(m_tempBus.get(), m_providerSize);
66
67 m_fifo.push(m_tempBus.get());
68
69 framesProvided += m_providerSize;
70 }
71 }
72
73 } // namespace blink
74
75 #endif // ENABLE(WEB_AUDIO)
76