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 * 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 #ifndef AudioResampler_h 26 #define AudioResampler_h 27 28 #include "platform/audio/AudioBus.h" 29 #include "platform/audio/AudioResamplerKernel.h" 30 #include "platform/audio/AudioSourceProvider.h" 31 #include "wtf/Noncopyable.h" 32 #include "wtf/OwnPtr.h" 33 #include "wtf/Vector.h" 34 35 namespace WebCore { 36 37 // AudioResampler resamples the audio stream from an AudioSourceProvider. 38 // The audio stream may be single or multi-channel. 39 // The default constructor defaults to single-channel (mono). 40 41 class PLATFORM_EXPORT AudioResampler { 42 WTF_MAKE_NONCOPYABLE(AudioResampler); 43 public: 44 AudioResampler(); 45 AudioResampler(unsigned numberOfChannels); ~AudioResampler()46 ~AudioResampler() { } 47 48 // Given an AudioSourceProvider, process() resamples the source stream into destinationBus. 49 void process(AudioSourceProvider*, AudioBus* destinationBus, size_t framesToProcess); 50 51 // Resets the processing state. 52 void reset(); 53 54 void configureChannels(unsigned numberOfChannels); 55 56 // 0 < rate <= MaxRate 57 void setRate(double rate); rate()58 double rate() const { return m_rate; } 59 60 static const double MaxRate; 61 62 private: 63 double m_rate; 64 Vector<OwnPtr<AudioResamplerKernel> > m_kernels; 65 RefPtr<AudioBus> m_sourceBus; 66 }; 67 68 } // namespace WebCore 69 70 #endif // AudioResampler_h 71