| /* |
| * 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 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 "config.h" |
| |
| #if ENABLE(WEB_AUDIO) |
| |
| #if OS(DARWIN) |
| |
| #include "FFTFrame.h" |
| |
| #include "VectorMath.h" |
| #include <wtf/Lock.h> |
| #include <wtf/NeverDestroyed.h> |
| #include <wtf/Vector.h> |
| |
| namespace WebCore { |
| |
| constexpr unsigned kMinFFTPow2Size = 2; |
| constexpr unsigned kMaxFFTPow2Size = 24; |
| |
| static Lock fftSetupsLock; |
| |
| static Vector<FFTSetup>& fftSetups() WTF_REQUIRES_LOCK(fftSetupsLock) |
| { |
| ASSERT(fftSetupsLock.isHeld()); |
| static NeverDestroyed<Vector<FFTSetup>> fftSetups(kMaxFFTPow2Size, nullptr); |
| return fftSetups; |
| } |
| |
| // Normal constructor: allocates for a given fftSize |
| FFTFrame::FFTFrame(unsigned fftSize) |
| : m_realData(fftSize) |
| , m_imagData(fftSize) |
| { |
| m_FFTSize = fftSize; |
| m_log2FFTSize = static_cast<unsigned>(log2(fftSize)); |
| |
| // We only allow power of two |
| ASSERT(1UL << m_log2FFTSize == m_FFTSize); |
| |
| // Lazily create and share fftSetup with other frames |
| m_FFTSetup = fftSetupForSize(fftSize); |
| |
| // Setup frame data |
| m_frame.realp = m_realData.data(); |
| m_frame.imagp = m_imagData.data(); |
| } |
| |
| // Creates a blank/empty frame (interpolate() must later be called) |
| FFTFrame::FFTFrame() |
| { |
| // Later will be set to correct values when interpolate() is called |
| m_frame.realp = 0; |
| m_frame.imagp = 0; |
| |
| m_FFTSize = 0; |
| m_log2FFTSize = 0; |
| } |
| |
| // Copy constructor |
| FFTFrame::FFTFrame(const FFTFrame& frame) |
| : m_FFTSize(frame.m_FFTSize) |
| , m_log2FFTSize(frame.m_log2FFTSize) |
| , m_FFTSetup(frame.m_FFTSetup) |
| , m_realData(frame.m_FFTSize) |
| , m_imagData(frame.m_FFTSize) |
| { |
| // Setup frame data |
| m_frame.realp = m_realData.data(); |
| m_frame.imagp = m_imagData.data(); |
| |
| // Copy/setup frame data |
| memcpy(realData().data(), frame.m_frame.realp, sizeof(float) * realData().size()); |
| memcpy(imagData().data(), frame.m_frame.imagp, sizeof(float) * imagData().size()); |
| } |
| |
| FFTFrame::~FFTFrame() = default; |
| |
| void FFTFrame::doFFT(const float* data) |
| { |
| unsigned halfSize = m_FFTSize / 2; |
| vDSP_ctoz(reinterpret_cast<const DSPComplex*>(data), 2, &m_frame, 1, halfSize); |
| vDSP_fft_zrip(m_FFTSetup, &m_frame, 1, m_log2FFTSize, FFT_FORWARD); |
| |
| RELEASE_ASSERT(realData().size() >= halfSize); |
| RELEASE_ASSERT(imagData().size() >= halfSize); |
| |
| // To provide the best possible execution speeds, the vDSP library's functions don't always adhere strictly |
| // to textbook formulas for Fourier transforms, and must be scaled accordingly. |
| // (See https://developer.apple.com/library/archive/documentation/Performance/Conceptual/vDSP_Programming_Guide/UsingFourierTransforms/UsingFourierTransforms.html#//apple_ref/doc/uid/TP40005147-CH3-SW5) |
| // In the case of a Real forward Transform like above: RFimp = RFmath * 2 so we need to divide the output |
| // by 2 to get the correct value. |
| VectorMath::multiplyByScalar(realData().data(), 0.5, realData().data(), halfSize); |
| VectorMath::multiplyByScalar(imagData().data(), 0.5, imagData().data(), halfSize); |
| } |
| |
| void FFTFrame::doInverseFFT(float* data) |
| { |
| vDSP_fft_zrip(m_FFTSetup, &m_frame, 1, m_log2FFTSize, FFT_INVERSE); |
| vDSP_ztoc(&m_frame, 1, (DSPComplex*)data, 2, m_FFTSize / 2); |
| |
| // Do final scaling so that x == IFFT(FFT(x)) |
| VectorMath::multiplyByScalar(data, 1.0f / m_FFTSize, data, m_FFTSize); |
| } |
| |
| FFTSetup FFTFrame::fftSetupForSize(unsigned fftSize) |
| { |
| auto pow2size = static_cast<size_t>(log2(fftSize)); |
| ASSERT(pow2size < kMaxFFTPow2Size); |
| |
| Locker locker { fftSetupsLock }; |
| auto& fftSetup = fftSetups().at(pow2size); |
| if (!fftSetup) |
| fftSetup = vDSP_create_fftsetup(pow2size, FFT_RADIX2); |
| |
| return fftSetup; |
| } |
| |
| int FFTFrame::minFFTSize() |
| { |
| return 1 << kMinFFTPow2Size; |
| } |
| |
| int FFTFrame::maxFFTSize() |
| { |
| return 1 << kMaxFFTPow2Size; |
| } |
| |
| void FFTFrame::initialize() |
| { |
| } |
| |
| } // namespace WebCore |
| |
| #endif // #if OS(DARWIN) |
| |
| #endif // ENABLE(WEB_AUDIO) |