The Tor Browser: content/media/webaudio/blink/HRTFPanner.h@6474c204b198

Cloned upstream origin tor-browser at tor-browser-31.3.0esr-4.5-1-build1
revision ID fc1c9ff7c1b2defdbc039f12214767608f46423f for hacking purpose.

     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  */

    25 #ifndef HRTFPanner_h

    26 #define HRTFPanner_h

    28 #include "FFTConvolver.h"

    29 #include "DelayBuffer.h"

    30 #include "mozilla/MemoryReporting.h"

    32 namespace mozilla {

    33 struct AudioChunk;

    34 }

    36 namespace WebCore {

    38 class HRTFDatabaseLoader;

    40 using mozilla::AudioChunk;

    42 class HRTFPanner {

    43 public:

    44     HRTFPanner(float sampleRate, mozilla::TemporaryRef<HRTFDatabaseLoader> databaseLoader);

    45     ~HRTFPanner();

    47     // chunk durations must be 128

    48     void pan(double azimuth, double elevation, const AudioChunk* inputBus, AudioChunk* outputBus);

    49     void reset();

    51     size_t fftSize() const { return m_convolverL1.fftSize(); }

    53     float sampleRate() const { return m_sampleRate; }

    55     int maxTailFrames() const;

    57     size_t sizeOfIncludingThis(mozilla::MallocSizeOf aMallocSizeOf) const;

    59 private:

    60     // Given an azimuth angle in the range -180 -> +180, returns the corresponding azimuth index for the database,

    61     // and azimuthBlend which is an interpolation value from 0 -> 1.

    62     int calculateDesiredAzimuthIndexAndBlend(double azimuth, double& azimuthBlend);

    64     mozilla::RefPtr<HRTFDatabaseLoader> m_databaseLoader;

    66     float m_sampleRate;

    68     // We maintain two sets of convolvers for smooth cross-faded interpolations when

    69     // then azimuth and elevation are dynamically changing.

    70     // When the azimuth and elevation are not changing, we simply process with one of the two sets.

    71     // Initially we use CrossfadeSelection1 corresponding to m_convolverL1 and m_convolverR1.

    72     // Whenever the azimuth or elevation changes, a crossfade is initiated to transition

    73     // to the new position. So if we're currently processing with CrossfadeSelection1, then

    74     // we transition to CrossfadeSelection2 (and vice versa).

    75     // If we're in the middle of a transition, then we wait until it is complete before

    76     // initiating a new transition.

    78     // Selects either the convolver set (m_convolverL1, m_convolverR1) or (m_convolverL2, m_convolverR2).

    79     enum CrossfadeSelection {

    80         CrossfadeSelection1,

    81         CrossfadeSelection2

    82     };

    84     CrossfadeSelection m_crossfadeSelection;

    86     // azimuth/elevation for CrossfadeSelection1.

    87     int m_azimuthIndex1;

    88     double m_elevation1;

    90     // azimuth/elevation for CrossfadeSelection2.

    91     int m_azimuthIndex2;

    92     double m_elevation2;

    94     // A crossfade value 0 <= m_crossfadeX <= 1.

    95     float m_crossfadeX;

    97     // Per-sample-frame crossfade value increment.

    98     float m_crossfadeIncr;

   100     FFTConvolver m_convolverL1;

   101     FFTConvolver m_convolverR1;

   102     FFTConvolver m_convolverL2;

   103     FFTConvolver m_convolverR2;

   105     mozilla::DelayBuffer m_delayLine;

   107     AudioFloatArray m_tempL1;

   108     AudioFloatArray m_tempR1;

   109     AudioFloatArray m_tempL2;

   110     AudioFloatArray m_tempR2;

   111 };

   113 } // namespace WebCore

   115 #endif // HRTFPanner_h

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