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 #ifndef WaveShaperDSPKernel_h 26 #define WaveShaperDSPKernel_h 27 28 #include "core/platform/audio/AudioArray.h" 29 #include "core/platform/audio/AudioDSPKernel.h" 30 #include "core/platform/audio/DownSampler.h" 31 #include "core/platform/audio/UpSampler.h" 32 #include "modules/webaudio/WaveShaperProcessor.h" 33 #include "wtf/OwnPtr.h" 34 35 namespace WebCore { 36 37 class WaveShaperProcessor; 38 39 // WaveShaperDSPKernel is an AudioDSPKernel and is responsible for non-linear distortion on one channel. 40 41 class WaveShaperDSPKernel : public AudioDSPKernel { 42 public: 43 explicit WaveShaperDSPKernel(WaveShaperProcessor*); 44 45 // AudioDSPKernel 46 virtual void process(const float* source, float* dest, size_t framesToProcess); 47 virtual void reset(); 48 virtual double tailTime() const OVERRIDE { return 0; } 49 virtual double latencyTime() const OVERRIDE; 50 51 // Oversampling requires more resources, so let's only allocate them if needed. 52 void lazyInitializeOversampling(); 53 54 protected: 55 // Apply the shaping curve. 56 void processCurve(const float* source, float* dest, size_t framesToProcess); 57 58 // Use up-sampling, process at the higher sample-rate, then down-sample. 59 void processCurve2x(const float* source, float* dest, size_t framesToProcess); 60 void processCurve4x(const float* source, float* dest, size_t framesToProcess); 61 62 WaveShaperProcessor* waveShaperProcessor() { return static_cast<WaveShaperProcessor*>(processor()); } 63 64 // Oversampling. 65 OwnPtr<AudioFloatArray> m_tempBuffer; 66 OwnPtr<AudioFloatArray> m_tempBuffer2; 67 OwnPtr<UpSampler> m_upSampler; 68 OwnPtr<DownSampler> m_downSampler; 69 OwnPtr<UpSampler> m_upSampler2; 70 OwnPtr<DownSampler> m_downSampler2; 71 }; 72 73 } // namespace WebCore 74 75 #endif // WaveShaperDSPKernel_h 76
