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/*
* 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.
*/
// Mac OS X - specific FFTFrame implementation
#include "build/build_config.h"
#if defined(OS_MACOSX)
#include "third_party/blink/renderer/platform/audio/fft_frame.h"
#include "third_party/blink/renderer/platform/audio/vector_math.h"
namespace blink {
const int kMaxFFTPow2Size = 24;
FFTSetup* FFTFrame::fft_setups_ = nullptr;
// Normal constructor: allocates for a given fftSize
FFTFrame::FFTFrame(unsigned fft_size)
: real_data_(fft_size), imag_data_(fft_size) {
fft_size_ = fft_size;
log2fft_size_ = static_cast<unsigned>(log2(fft_size));
// We only allow power of two
DCHECK_EQ(1UL << log2fft_size_, fft_size_);
// Lazily create and share fftSetup with other frames
fft_setup_ = FftSetupForSize(fft_size);
// Setup frame data
frame_.realp = real_data_.Data();
frame_.imagp = imag_data_.Data();
}
// Creates a blank/empty frame (interpolate() must later be called)
FFTFrame::FFTFrame() : real_data_(0), imag_data_(0) {
// Later will be set to correct values when interpolate() is called
frame_.realp = 0;
frame_.imagp = 0;
fft_size_ = 0;
log2fft_size_ = 0;
}
// Copy constructor
FFTFrame::FFTFrame(const FFTFrame& frame)
: fft_size_(frame.fft_size_),
log2fft_size_(frame.log2fft_size_),
real_data_(frame.fft_size_),
imag_data_(frame.fft_size_),
fft_setup_(frame.fft_setup_) {
// Setup frame data
frame_.realp = real_data_.Data();
frame_.imagp = imag_data_.Data();
// Copy/setup frame data
unsigned nbytes = sizeof(float) * fft_size_;
memcpy(RealData(), frame.frame_.realp, nbytes);
memcpy(ImagData(), frame.frame_.imagp, nbytes);
}
FFTFrame::~FFTFrame() {}
void FFTFrame::DoFFT(const float* data) {
AudioFloatArray scaled_data(fft_size_);
// veclib fft returns a result that is twice as large as would be expected.
// Compensate for that by scaling the input by half so the FFT has the
// correct scaling.
float scale = 0.5f;
VectorMath::Vsmul(data, 1, &scale, scaled_data.Data(), 1, fft_size_);
vDSP_ctoz((DSPComplex*)scaled_data.Data(), 2, &frame_, 1, fft_size_ / 2);
vDSP_fft_zrip(fft_setup_, &frame_, 1, log2fft_size_, FFT_FORWARD);
}
void FFTFrame::DoInverseFFT(float* data) {
vDSP_fft_zrip(fft_setup_, &frame_, 1, log2fft_size_, FFT_INVERSE);
vDSP_ztoc(&frame_, 1, (DSPComplex*)data, 2, fft_size_ / 2);
// Do final scaling so that x == IFFT(FFT(x))
float scale = 1.0f / fft_size_;
VectorMath::Vsmul(data, 1, &scale, data, 1, fft_size_);
}
FFTSetup FFTFrame::FftSetupForSize(unsigned fft_size) {
if (!fft_setups_) {
fft_setups_ = (FFTSetup*)malloc(sizeof(FFTSetup) * kMaxFFTPow2Size);
memset(fft_setups_, 0, sizeof(FFTSetup) * kMaxFFTPow2Size);
}
int pow2size = static_cast<int>(log2(fft_size));
DCHECK_LT(pow2size, kMaxFFTPow2Size);
if (!fft_setups_[pow2size])
fft_setups_[pow2size] = vDSP_create_fftsetup(pow2size, FFT_RADIX2);
return fft_setups_[pow2size];
}
void FFTFrame::Initialize() {}
void FFTFrame::Cleanup() {
if (!fft_setups_)
return;
for (int i = 0; i < kMaxFFTPow2Size; ++i) {
if (fft_setups_[i])
vDSP_destroy_fftsetup(fft_setups_[i]);
}
free(fft_setups_);
fft_setups_ = nullptr;
}
} // namespace blink
#endif // #if defined(OS_MACOSX)
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