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

/*
 * Copyright (C) 2010 Google Inc. All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 *
 * 1.  Redistributions of source code must retain the above copyright
 *     notice, this list of conditions and the following disclaimer.
 * 2.  Redistributions in binary form must reproduce the above copyright
 *     notice, this list of conditions and the following disclaimer in the
 *     documentation and/or other materials provided with the distribution.
 * 3.  Neither the name of Apple Computer, Inc. ("Apple") nor the names of
 *     its contributors may be used to endorse or promote products derived
 *     from this software without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY APPLE AND ITS CONTRIBUTORS "AS IS" AND ANY
 * EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
 * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
 * DISCLAIMED. IN NO EVENT SHALL APPLE OR ITS CONTRIBUTORS BE LIABLE FOR ANY
 * DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
 * (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
 * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
 * ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 */

#ifndef FFTFrame_h
#define FFTFrame_h

#include "platform/PlatformExport.h"
#include "platform/audio/AudioArray.h"
#include "wtf/Allocator.h"
#include "wtf/Forward.h"
#include "wtf/Threading.h"
#include <memory>

#if OS(MACOSX)
#include <Accelerate/Accelerate.h>
#elif USE(WEBAUDIO_OPENMAX_DL_FFT)
#include <dl/sp/api/omxSP.h>
#elif USE(WEBAUDIO_FFMPEG)
struct RDFTContext;
#endif

namespace blink {

// Defines the interface for an "FFT frame", an object which is able to perform
// a forward and reverse FFT, internally storing the resultant frequency-domain
// data.

class PLATFORM_EXPORT FFTFrame {
  USING_FAST_MALLOC(FFTFrame);

 public:
  // The constructors, destructor, and methods up to the CROSS-PLATFORM section
  // have platform-dependent implementations.

  FFTFrame(unsigned fftSize);
  // creates a blank/empty frame for later use with createInterpolatedFrame()
  FFTFrame();
  FFTFrame(const FFTFrame& frame);
  ~FFTFrame();

  static void initialize();
  static void cleanup();
  void doFFT(const float* data);
  void doInverseFFT(float* data);

  float* realData() const { return const_cast<float*>(m_realData.data()); }
  float* imagData() const { return const_cast<float*>(m_imagData.data()); }

  unsigned fftSize() const { return m_FFTSize; }
  unsigned log2FFTSize() const { return m_log2FFTSize; }

  // CROSS-PLATFORM
  // The remaining public methods have cross-platform implementations:

  // Interpolates from frame1 -> frame2 as x goes from 0.0 -> 1.0
  static std::unique_ptr<FFTFrame> createInterpolatedFrame(
      const FFTFrame& frame1,
      const FFTFrame& frame2,
      double x);
  // zero-padding with dataSize <= fftSize
  void doPaddedFFT(const float* data, size_t dataSize);
  double extractAverageGroupDelay();
  void addConstantGroupDelay(double sampleFrameDelay);
  // multiplies ourself with frame : effectively operator*=()
  void multiply(const FFTFrame&);

 private:
  void interpolateFrequencyComponents(const FFTFrame& frame1,
                                      const FFTFrame& frame2,
                                      double x);

  unsigned m_FFTSize;
  unsigned m_log2FFTSize;
  AudioFloatArray m_realData;
  AudioFloatArray m_imagData;

#if OS(MACOSX)
  DSPSplitComplex& dspSplitComplex() { return m_frame; }
  DSPSplitComplex dspSplitComplex() const { return m_frame; }
  static FFTSetup fftSetupForSize(unsigned fftSize);
  static FFTSetup* fftSetups;
  FFTSetup m_FFTSetup;
  DSPSplitComplex m_frame;
#elif USE(WEBAUDIO_FFMPEG)
  static RDFTContext* contextForSize(unsigned fftSize, int trans);
  RDFTContext* m_forwardContext;
  RDFTContext* m_inverseContext;
  float* getUpToDateComplexData();
  AudioFloatArray m_complexData;
#elif USE(WEBAUDIO_OPENMAX_DL_FFT)
  static OMXFFTSpec_R_F32* contextForSize(unsigned log2FFTSize);
  OMXFFTSpec_R_F32* m_forwardContext;
  OMXFFTSpec_R_F32* m_inverseContext;
  AudioFloatArray m_complexData;
#endif
};

}  // namespace blink

#endif  // FFTFrame_h