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 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 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 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