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             :  *
       8             :  * 1.  Redistributions of source code must retain the above copyright
       9             :  *     notice, this list of conditions and the following disclaimer.
      10             :  * 2.  Redistributions in binary form must reproduce the above copyright
      11             :  *     notice, this list of conditions and the following disclaimer in the
      12             :  *     documentation and/or other materials provided with the distribution.
      13             :  * 3.  Neither the name of Apple Computer, Inc. ("Apple") nor the names of
      14             :  *     its contributors may be used to endorse or promote products derived
      15             :  *     from this software without specific prior written permission.
      16             :  *
      17             :  * THIS SOFTWARE IS PROVIDED BY APPLE AND ITS CONTRIBUTORS "AS IS" AND ANY
      18             :  * EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
      19             :  * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
      20             :  * DISCLAIMED. IN NO EVENT SHALL APPLE OR ITS CONTRIBUTORS BE LIABLE FOR ANY
      21             :  * DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
      22             :  * (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
      23             :  * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
      24             :  * ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
      25             :  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
      26             :  * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
      27             :  */
      28             : 
      29             : #ifndef HRTFKernel_h
      30             : #define HRTFKernel_h
      31             : 
      32             : #include "nsAutoPtr.h"
      33             : #include "nsAutoRef.h"
      34             : #include "nsTArray.h"
      35             : #include "mozilla/FFTBlock.h"
      36             : #include "mozilla/MemoryReporting.h"
      37             : 
      38             : namespace WebCore {
      39             : 
      40             : using mozilla::FFTBlock;
      41             : 
      42             : // HRTF stands for Head-Related Transfer Function.
      43             : // HRTFKernel is a frequency-domain representation of an impulse-response used as part of the spatialized panning system.
      44             : // For a given azimuth / elevation angle there will be one HRTFKernel for the left ear transfer function, and one for the right ear.
      45             : // The leading delay (average group delay) for each impulse response is extracted:
      46             : //      m_fftFrame is the frequency-domain representation of the impulse response with the delay removed
      47             : //      m_frameDelay is the leading delay of the original impulse response.
      48           0 : class HRTFKernel {
      49             : public:
      50             :     // Note: this is destructive on the passed in |impulseResponse|.
      51             :     // The |length| of |impulseResponse| must be a power of two.
      52             :     // The size of the DFT will be |2 * length|.
      53             :     static nsReturnRef<HRTFKernel> create(float* impulseResponse, size_t length, float sampleRate);
      54             : 
      55             :     static nsReturnRef<HRTFKernel> create(nsAutoPtr<FFTBlock> fftFrame, float frameDelay, float sampleRate);
      56             : 
      57             :     // Given two HRTFKernels, and an interpolation factor x: 0 -> 1, returns an interpolated HRTFKernel.
      58             :     static nsReturnRef<HRTFKernel> createInterpolatedKernel(HRTFKernel* kernel1, HRTFKernel* kernel2, float x);
      59             : 
      60           0 :     FFTBlock* fftFrame() { return m_fftFrame.get(); }
      61             : 
      62             :     size_t fftSize() const { return m_fftFrame->FFTSize(); }
      63           0 :     float frameDelay() const { return m_frameDelay; }
      64             : 
      65           0 :     float sampleRate() const { return m_sampleRate; }
      66             :     double nyquist() const { return 0.5 * sampleRate(); }
      67             : 
      68           0 :     size_t sizeOfIncludingThis(mozilla::MallocSizeOf aMallocSizeOf) const
      69             :     {
      70           0 :         size_t amount = aMallocSizeOf(this);
      71           0 :         amount += m_fftFrame->SizeOfIncludingThis(aMallocSizeOf);
      72           0 :         return amount;
      73             :     }
      74             : 
      75             : private:
      76             :     HRTFKernel(const HRTFKernel& other) = delete;
      77             :     void operator=(const HRTFKernel& other) = delete;
      78             : 
      79             :     // Note: this is destructive on the passed in |impulseResponse|.
      80             :     HRTFKernel(float* impulseResponse, size_t fftSize, float sampleRate);
      81             : 
      82           0 :     HRTFKernel(nsAutoPtr<FFTBlock> fftFrame, float frameDelay, float sampleRate)
      83           0 :         : m_fftFrame(fftFrame)
      84             :         , m_frameDelay(frameDelay)
      85           0 :         , m_sampleRate(sampleRate)
      86             :     {
      87           0 :     }
      88             : 
      89             :     nsAutoPtr<FFTBlock> m_fftFrame;
      90             :     float m_frameDelay;
      91             :     float m_sampleRate;
      92             : };
      93             : 
      94             : typedef nsTArray<nsAutoRef<HRTFKernel> > HRTFKernelList;
      95             : 
      96             : } // namespace WebCore
      97             : 
      98             : template <>
      99           0 : class nsAutoRefTraits<WebCore::HRTFKernel> :
     100             :     public nsPointerRefTraits<WebCore::HRTFKernel> {
     101             : public:
     102           0 :     static void Release(WebCore::HRTFKernel* ptr) { delete(ptr); }
     103             : };
     104             : 
     105             : namespace WebCore {
     106             : 
     107           0 : inline nsReturnRef<HRTFKernel> HRTFKernel::create(float* impulseResponse, size_t length, float sampleRate)
     108             : {
     109           0 :     return nsReturnRef<HRTFKernel>(new HRTFKernel(impulseResponse, length, sampleRate));
     110             : }
     111             : 
     112           0 : inline nsReturnRef<HRTFKernel> HRTFKernel::create(nsAutoPtr<FFTBlock> fftFrame, float frameDelay, float sampleRate)
     113             : {
     114           0 :     return nsReturnRef<HRTFKernel>(new HRTFKernel(fftFrame, frameDelay, sampleRate));
     115             : }
     116             : 
     117             : } // namespace WebCore
     118             : 
     119             : #endif // HRTFKernel_h