tor-browser

The Tor Browser
git clone https://git.dasho.dev/tor-browser.git
Log | Files | Refs | README | LICENSE

HRTFPanner.h (4161B)

      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
     14 * ANY 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
     17 * ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
     18 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
     19 * SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
     20 * CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
     21 * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
     22 * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
     23 */
     24 
     25 #ifndef HRTFPanner_h
     26 #define HRTFPanner_h
     27 
     28 #include "DelayBuffer.h"
     29 #include "FFTConvolver.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,
     47             already_AddRefed<HRTFDatabaseLoader> databaseLoader);
     48  ~HRTFPanner();
     49 
     50  // chunk durations must be 128
     51  void pan(double azimuth, double elevation, const AudioBlock* inputBus,
     52           AudioBlock* outputBus);
     53  void reset();
     54 
     55  size_t fftSize() const { return m_convolverL1.fftSize(); }
     56 
     57  float sampleRate() const { return m_sampleRate; }
     58 
     59  int maxTailFrames() const;
     60 
     61  size_t sizeOfIncludingThis(mozilla::MallocSizeOf aMallocSizeOf) const;
     62 
     63 private:
     64  // Given an azimuth angle in the range -180 -> +180, returns the corresponding
     65  // azimuth index for the database, and azimuthBlend which is an interpolation
     66  // value from 0 -> 1.
     67  int calculateDesiredAzimuthIndexAndBlend(double azimuth,
     68                                           double& azimuthBlend);
     69 
     70  RefPtr<HRTFDatabaseLoader> m_databaseLoader;
     71 
     72  float m_sampleRate;
     73 
     74  // We maintain two sets of convolvers for smooth cross-faded interpolations
     75  // when then azimuth and elevation are dynamically changing. When the azimuth
     76  // and elevation are not changing, we simply process with one of the two sets.
     77  // Initially we use CrossfadeSelection1 corresponding to m_convolverL1 and
     78  // m_convolverR1. Whenever the azimuth or elevation changes, a crossfade is
     79  // initiated to transition to the new position. So if we're currently
     80  // processing with CrossfadeSelection1, then we transition to
     81  // CrossfadeSelection2 (and vice versa). If we're in the middle of a
     82  // transition, then we wait until it is complete before initiating a new
     83  // transition.
     84 
     85  // Selects either the convolver set (m_convolverL1, m_convolverR1) or
     86  // (m_convolverL2, m_convolverR2).
     87  enum CrossfadeSelection { CrossfadeSelection1, CrossfadeSelection2 };
     88 
     89  CrossfadeSelection m_crossfadeSelection;
     90 
     91  // azimuth/elevation for CrossfadeSelection1.
     92  int m_azimuthIndex1;
     93  double m_elevation1;
     94 
     95  // azimuth/elevation for CrossfadeSelection2.
     96  int m_azimuthIndex2;
     97  double m_elevation2;
     98 
     99  // A crossfade value 0 <= m_crossfadeX <= 1.
    100  float m_crossfadeX;
    101 
    102  // Per-sample-frame crossfade value increment.
    103  float m_crossfadeIncr;
    104 
    105  FFTConvolver m_convolverL1;
    106  FFTConvolver m_convolverR1;
    107  FFTConvolver m_convolverL2;
    108  FFTConvolver m_convolverR2;
    109 
    110  mozilla::DelayBuffer m_delayLine;
    111 
    112  AudioFloatArray m_tempL1;
    113  AudioFloatArray m_tempR1;
    114  AudioFloatArray m_tempL2;
    115  AudioFloatArray m_tempR2;
    116 };
    117 
    118 }  // namespace WebCore
    119 
    120 #endif  // HRTFPanner_h