| /* |
| * Copyright (C) 2010, Google Inc. All rights reserved. |
| * |
| * Redistribution and use in source and binary forms, with or without |
| * modification, are permitted provided that the following conditions |
| * are met: |
| * 1. Redistributions of source code must retain the above copyright |
| * notice, this list of conditions and the following disclaimer. |
| * 2. Redistributions in binary form must reproduce the above copyright |
| * notice, this list of conditions and the following disclaimer in the |
| * documentation and/or other materials provided with the distribution. |
| * |
| * THIS SOFTWARE IS PROVIDED BY APPLE INC. AND ITS CONTRIBUTORS ``AS IS'' AND ANY |
| * EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED |
| * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE |
| * DISCLAIMED. IN NO EVENT SHALL APPLE INC. OR ITS CONTRIBUTORS BE LIABLE FOR ANY |
| * DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES |
| * (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; |
| * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON |
| * ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT |
| * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS |
| * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. |
| */ |
| |
| #ifndef HRTFPanner_h |
| #define HRTFPanner_h |
| |
| #include "platform/audio/AudioDelayDSPKernel.h" |
| #include "platform/audio/FFTConvolver.h" |
| #include "platform/audio/HRTFDatabaseLoader.h" |
| #include "platform/audio/Panner.h" |
| |
| namespace WebCore { |
| |
| class PLATFORM_EXPORT HRTFPanner : public Panner { |
| public: |
| HRTFPanner(float sampleRate, HRTFDatabaseLoader*); |
| virtual ~HRTFPanner(); |
| |
| // Panner |
| virtual void pan(double azimuth, double elevation, const AudioBus* inputBus, AudioBus* outputBus, size_t framesToProcess); |
| virtual void reset(); |
| |
| size_t fftSize() const { return fftSizeForSampleRate(m_sampleRate); } |
| static size_t fftSizeForSampleRate(float sampleRate); |
| |
| float sampleRate() const { return m_sampleRate; } |
| |
| virtual double tailTime() const OVERRIDE; |
| virtual double latencyTime() const OVERRIDE; |
| |
| private: |
| // Given an azimuth angle in the range -180 -> +180, returns the corresponding azimuth index for the database, |
| // and azimuthBlend which is an interpolation value from 0 -> 1. |
| int calculateDesiredAzimuthIndexAndBlend(double azimuth, double& azimuthBlend); |
| |
| RefPtr<HRTFDatabaseLoader> m_databaseLoader; |
| |
| float m_sampleRate; |
| |
| // We maintain two sets of convolvers for smooth cross-faded interpolations when |
| // then azimuth and elevation are dynamically changing. |
| // When the azimuth and elevation are not changing, we simply process with one of the two sets. |
| // Initially we use CrossfadeSelection1 corresponding to m_convolverL1 and m_convolverR1. |
| // Whenever the azimuth or elevation changes, a crossfade is initiated to transition |
| // to the new position. So if we're currently processing with CrossfadeSelection1, then |
| // we transition to CrossfadeSelection2 (and vice versa). |
| // If we're in the middle of a transition, then we wait until it is complete before |
| // initiating a new transition. |
| |
| // Selects either the convolver set (m_convolverL1, m_convolverR1) or (m_convolverL2, m_convolverR2). |
| enum CrossfadeSelection { |
| CrossfadeSelection1, |
| CrossfadeSelection2 |
| }; |
| |
| CrossfadeSelection m_crossfadeSelection; |
| |
| // azimuth/elevation for CrossfadeSelection1. |
| int m_azimuthIndex1; |
| double m_elevation1; |
| |
| // azimuth/elevation for CrossfadeSelection2. |
| int m_azimuthIndex2; |
| double m_elevation2; |
| |
| // A crossfade value 0 <= m_crossfadeX <= 1. |
| float m_crossfadeX; |
| |
| // Per-sample-frame crossfade value increment. |
| float m_crossfadeIncr; |
| |
| FFTConvolver m_convolverL1; |
| FFTConvolver m_convolverR1; |
| FFTConvolver m_convolverL2; |
| FFTConvolver m_convolverR2; |
| |
| AudioDelayDSPKernel m_delayLineL; |
| AudioDelayDSPKernel m_delayLineR; |
| |
| AudioFloatArray m_tempL1; |
| AudioFloatArray m_tempR1; |
| AudioFloatArray m_tempL2; |
| AudioFloatArray m_tempR2; |
| }; |
| |
| } // namespace WebCore |
| |
| #endif // HRTFPanner_h |