third_party/WebKit/Source/platform/audio/EqualPowerPanner.h

   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 EqualPowerPanner_h
  26 #define EqualPowerPanner_h
  27
  28 #include "platform/audio/Panner.h"
  29
  30 namespace blink {
  31
  32 // Common type of stereo panner as found in normal audio mixing equipment.
  33
  34 class PLATFORM_EXPORT EqualPowerPanner final : public Panner {
  35 public:
  36     EqualPowerPanner(float sampleRate);
  37
  38     void pan(double azimuth, double elevation, const AudioBus* inputBus, AudioBus* outputBuf, size_t framesToProcess) override;
  39
  40     void reset() override { m_isFirstRender = true; }
  41
  42     double tailTime() const override { return 0; }
  43     double latencyTime() const override { return 0; }
  44
  45 private:
  46     // For smoothing / de-zippering
  47     bool m_isFirstRender;
  48     double m_smoothingConstant;
  49
  50     double m_gainL;
  51     double m_gainR;
  52 };
  53
  54 } // namespace blink
  55
  56 #endif // EqualPowerPanner_h