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80 lines
2.1 KiB
C
80 lines
2.1 KiB
C
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/* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
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/* vim:set ts=2 sw=2 sts=2 et cindent: */
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/* This Source Code Form is subject to the terms of the Mozilla Public
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* License, v. 2.0. If a copy of the MPL was not distributed with this
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* file, You can obtain one at http://mozilla.org/MPL/2.0/. */
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#ifndef FFTBlock_h_
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#define FFTBlock_h_
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#include "nsTArray.h"
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#include "AudioNodeEngine.h"
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#include "kiss_fft/kiss_fftr.h"
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namespace mozilla {
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// This class defines an FFT block, loosely modeled after Blink's FFTFrame
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// class to make sharing code with Blink easy.
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// Currently it's implemented on top of KissFFT on all platforms.
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class FFTBlock {
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public:
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explicit FFTBlock(uint32_t aFFTSize)
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: mFFTSize(aFFTSize)
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{
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mOutputBuffer.SetLength(aFFTSize / 2 + 1);
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PodZero(mOutputBuffer.Elements(), aFFTSize / 2 + 1);
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}
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void PerformFFT(const float* aData)
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{
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kiss_fftr_cfg fft = kiss_fftr_alloc(mFFTSize, 0, nullptr, nullptr);
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kiss_fftr(fft, aData, mOutputBuffer.Elements());
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free(fft);
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}
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void PerformInverseFFT(float* aData) const
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{
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kiss_fftr_cfg fft = kiss_fftr_alloc(mFFTSize, 1, nullptr, nullptr);
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kiss_fftri(fft, mOutputBuffer.Elements(), aData);
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free(fft);
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for (uint32_t i = 0; i < mFFTSize; ++i) {
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aData[i] /= mFFTSize;
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}
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}
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void Multiply(const FFTBlock& aFrame)
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{
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BufferComplexMultiply(reinterpret_cast<const float*>(mOutputBuffer.Elements()),
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reinterpret_cast<const float*>(aFrame.mOutputBuffer.Elements()),
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reinterpret_cast<float*>(mOutputBuffer.Elements()),
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mFFTSize / 2 + 1);
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}
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void SetFFTSize(uint32_t aSize)
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{
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mFFTSize = aSize;
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mOutputBuffer.SetLength(aSize / 2 + 1);
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PodZero(mOutputBuffer.Elements(), aSize / 2 + 1);
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}
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float FFTSize() const
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{
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return mFFTSize;
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}
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float RealData(uint32_t aIndex) const
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{
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return mOutputBuffer[aIndex].r;
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}
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float ImagData(uint32_t aIndex) const
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{
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return mOutputBuffer[aIndex].i;
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}
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private:
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nsTArray<kiss_fft_cpx> mOutputBuffer;
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uint32_t mFFTSize;
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};
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}
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#endif
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