Line data    Source code

       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 HRTFPanner_h
      26             : #define HRTFPanner_h
      27             : 
      28             : #include "FFTConvolver.h"
      29             : #include "DelayBuffer.h"
      30             : #include "mozilla/MemoryReporting.h"
      31             : 
      32             : namespace mozilla {
      33             : class AudioBlock;
      34             : } // namespace mozilla
      35             : 
      36             : namespace WebCore {
      37             : 
      38             : typedef nsTArray<float> AudioFloatArray;
      39             : 
      40             : class HRTFDatabaseLoader;
      41             : 
      42             : using mozilla::AudioBlock;
      43             : 
      44             : class HRTFPanner {
      45             : public:
      46             :     HRTFPanner(float sampleRate, already_AddRefed<HRTFDatabaseLoader> databaseLoader);
      47             :     ~HRTFPanner();
      48             : 
      49             :     // chunk durations must be 128
      50             :     void pan(double azimuth, double elevation, const AudioBlock* inputBus, AudioBlock* outputBus);
      51             :     void reset();
      52             : 
      53             :     size_t fftSize() const { return m_convolverL1.fftSize(); }
      54             : 
      55           0 :     float sampleRate() const { return m_sampleRate; }
      56             : 
      57             :     int maxTailFrames() const;
      58             : 
      59             :     size_t sizeOfIncludingThis(mozilla::MallocSizeOf aMallocSizeOf) const;
      60             : 
      61             : private:
      62             :     // Given an azimuth angle in the range -180 -> +180, returns the corresponding azimuth index for the database,
      63             :     // and azimuthBlend which is an interpolation value from 0 -> 1.
      64             :     int calculateDesiredAzimuthIndexAndBlend(double azimuth, double& azimuthBlend);
      65             : 
      66             :     RefPtr<HRTFDatabaseLoader> m_databaseLoader;
      67             : 
      68             :     float m_sampleRate;
      69             : 
      70             :     // We maintain two sets of convolvers for smooth cross-faded interpolations when
      71             :     // then azimuth and elevation are dynamically changing.
      72             :     // When the azimuth and elevation are not changing, we simply process with one of the two sets.
      73             :     // Initially we use CrossfadeSelection1 corresponding to m_convolverL1 and m_convolverR1.
      74             :     // Whenever the azimuth or elevation changes, a crossfade is initiated to transition
      75             :     // to the new position. So if we're currently processing with CrossfadeSelection1, then
      76             :     // we transition to CrossfadeSelection2 (and vice versa).
      77             :     // If we're in the middle of a transition, then we wait until it is complete before
      78             :     // initiating a new transition.
      79             : 
      80             :     // Selects either the convolver set (m_convolverL1, m_convolverR1) or (m_convolverL2, m_convolverR2).
      81             :     enum CrossfadeSelection {
      82             :         CrossfadeSelection1,
      83             :         CrossfadeSelection2
      84             :     };
      85             : 
      86             :     CrossfadeSelection m_crossfadeSelection;
      87             : 
      88             :     // azimuth/elevation for CrossfadeSelection1.
      89             :     int m_azimuthIndex1;
      90             :     double m_elevation1;
      91             : 
      92             :     // azimuth/elevation for CrossfadeSelection2.
      93             :     int m_azimuthIndex2;
      94             :     double m_elevation2;
      95             : 
      96             :     // A crossfade value 0 <= m_crossfadeX <= 1.
      97             :     float m_crossfadeX;
      98             : 
      99             :     // Per-sample-frame crossfade value increment.
     100             :     float m_crossfadeIncr;
     101             : 
     102             :     FFTConvolver m_convolverL1;
     103             :     FFTConvolver m_convolverR1;
     104             :     FFTConvolver m_convolverL2;
     105             :     FFTConvolver m_convolverR2;
     106             : 
     107             :     mozilla::DelayBuffer m_delayLine;
     108             : 
     109             :     AudioFloatArray m_tempL1;
     110             :     AudioFloatArray m_tempR1;
     111             :     AudioFloatArray m_tempL2;
     112             :     AudioFloatArray m_tempR2;
     113             : };
     114             : 
     115             : } // namespace WebCore
     116             : 
     117             : #endif // HRTFPanner_h