third_party/WebKit/Source/platform/audio/ipp/FFTFrameIPP.cpp

/*
 * Copyright (C) 2011 Google Inc. All rights reserved.
 * Copyright (C) 2012 Intel 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.
 *
 * 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
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 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 */

// FFTFrame implementation using Intel IPP's DFT algorithm,
// suitable for use on Linux.

#include "wtf/build_config.h"

#if USE(WEBAUDIO_IPP)

#include "platform/audio/FFTFrame.h"

#include "wtf/MathExtras.h"

namespace blink {

const unsigned maximumFFTPower2Size = 24;

// Normal constructor: allocates for a given fftSize.
FFTFrame::FFTFrame(unsigned fftSize)
    : m_FFTSize(fftSize),
      m_log2FFTSize(static_cast<unsigned>(log2(fftSize))),
      m_realData(fftSize / 2),
      m_imagData(fftSize / 2),
      m_complexData(fftSize) {
  // We only allow power of two.
  ASSERT(1UL << m_log2FFTSize == m_FFTSize);
  ASSERT(m_log2FFTSize <= maximumFFTPower2Size);

  ippsDFTInitAlloc_R_32f(&m_DFTSpec, m_FFTSize, IPP_FFT_NODIV_BY_ANY,
                         ippAlgHintFast);
  int bufferSize = 0;
  ippsDFTGetBufSize_R_32f(m_DFTSpec, &bufferSize);
  m_buffer = ippsMalloc_8u(bufferSize);
}

// Creates a blank/empty frame (interpolate() must later be called).
FFTFrame::FFTFrame() : m_FFTSize(0), m_log2FFTSize(0) {}

// Copy constructor.
FFTFrame::FFTFrame(const FFTFrame& frame)
    : m_FFTSize(frame.m_FFTSize),
      m_log2FFTSize(frame.m_log2FFTSize),
      m_realData(frame.m_FFTSize / 2),
      m_imagData(frame.m_FFTSize / 2),
      m_complexData(frame.m_FFTSize) {
  ippsDFTInitAlloc_R_32f(&m_DFTSpec, m_FFTSize, IPP_FFT_NODIV_BY_ANY,
                         ippAlgHintFast);
  int bufferSize = 0;
  ippsDFTGetBufSize_R_32f(m_DFTSpec, &bufferSize);
  m_buffer = ippsMalloc_8u(bufferSize);

  // Copy/setup frame data.
  unsigned numberOfBytes = sizeof(float) * m_FFTSize;
  memcpy(realData(), frame.realData(), numberOfBytes);
  memcpy(imagData(), frame.imagData(), numberOfBytes);
}

void FFTFrame::initialize() {}

void FFTFrame::cleanup() {}

FFTFrame::~FFTFrame() {
  ippsFree(m_buffer);
  ippsDFTFree_R_32f(m_DFTSpec);
}

void FFTFrame::doFFT(const float* data) {
  Ipp32f* complexP = m_complexData.data();

  // Compute Forward transform to perm format.
  ippsDFTFwd_RToPerm_32f(reinterpret_cast<Ipp32f*>(const_cast<float*>(data)),
                         complexP, m_DFTSpec, m_buffer);

  Ipp32f* realP = m_realData.data();
  Ipp32f* imagP = m_imagData.data();
  ippsCplxToReal_32fc(reinterpret_cast<Ipp32fc*>(complexP), realP, imagP,
                      m_FFTSize >> 1);
}

void FFTFrame::doInverseFFT(float* data) {
  Ipp32f* complexP = getUpToDateComplexData();

  // Compute inverse transform.
  ippsDFTInv_PermToR_32f(complexP, reinterpret_cast<Ipp32f*>(data), m_DFTSpec,
                         m_buffer);

  // Scale so that a forward then inverse FFT yields exactly the original data.
  const float scale = 1.0 / m_FFTSize;

  ippsMulC_32f_I(scale, reinterpret_cast<Ipp32f*>(data), m_FFTSize);
}

float* FFTFrame::getUpToDateComplexData() {
  int len = m_FFTSize >> 1;
  // Merge the real and imagimary vectors to complex vector.
  Ipp32f* realP = m_realData.data();
  Ipp32f* imagP = m_imagData.data();
  Ipp32fc* complexP = reinterpret_cast<Ipp32fc*>(m_complexData.data());
  ippsRealToCplx_32f(realP, imagP, complexP, len);

  return const_cast<float*>(m_complexData.data());
}

}  // namespace blink

#endif  // USE(WEBAUDIO_IPP)