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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.
*
* 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.
*/
// FFTFrame implementation using Intel's Math Kernel Library (MKL),
// suitable for use on Windows and Linux.
#include "config.h"
#if ENABLE(WEB_AUDIO)
#include "FFTFrame.h"
#include "mkl_vml.h"
#include <wtf/MathExtras.h>
namespace {
DFTI_DESCRIPTOR_HANDLE createDescriptorHandle(int fftSize)
{
DFTI_DESCRIPTOR_HANDLE handle = 0;
// Create DFTI descriptor for 1D single precision transform.
MKL_LONG status = DftiCreateDescriptor(&handle, DFTI_SINGLE, DFTI_REAL, 1, fftSize);
ASSERT(DftiErrorClass(status, DFTI_NO_ERROR));
// Set placement of result to DFTI_NOT_INPLACE.
status = DftiSetValue(handle, DFTI_PLACEMENT, DFTI_NOT_INPLACE);
ASSERT(DftiErrorClass(status, DFTI_NO_ERROR));
// Set packing format to PERM; this produces the layout which
// matches Accelerate.framework's on the Mac, though interleaved.
status = DftiSetValue(handle, DFTI_PACKED_FORMAT, DFTI_PERM_FORMAT);
ASSERT(DftiErrorClass(status, DFTI_NO_ERROR));
// Set the forward scale factor to 2 to match Accelerate.framework's.
// FIXME: FFTFrameMac's scaling factor could be fixed to be 1.0,
// in which case this code would need to be changed as well.
status = DftiSetValue(handle, DFTI_FORWARD_SCALE, 2.0);
ASSERT(DftiErrorClass(status, DFTI_NO_ERROR));
// Set the backward scale factor to 1 / 2n to match Accelerate.framework's.
// FIXME: if the above scaling factor is fixed then this needs to be as well.
double scale = 1.0 / (2.0 * fftSize);
status = DftiSetValue(handle, DFTI_BACKWARD_SCALE, scale);
ASSERT(DftiErrorClass(status, DFTI_NO_ERROR));
// Use the default DFTI_CONJUGATE_EVEN_STORAGE = DFTI_COMPLEX_REAL.
// Commit DFTI descriptor.
status = DftiCommitDescriptor(handle);
ASSERT(DftiErrorClass(status, DFTI_NO_ERROR));
return handle;
}
} // anonymous namespace
namespace WebCore {
const int kMaxFFTPow2Size = 24;
DFTI_DESCRIPTOR_HANDLE* FFTFrame::descriptorHandles = 0;
// Normal constructor: allocates for a given fftSize.
FFTFrame::FFTFrame(unsigned fftSize)
: m_FFTSize(fftSize)
, m_log2FFTSize(static_cast<unsigned>(log2(fftSize)))
, m_handle(0)
, m_complexData(fftSize)
, m_realData(fftSize / 2)
, m_imagData(fftSize / 2)
{
// We only allow power of two.
ASSERT(1UL << m_log2FFTSize == m_FFTSize);
m_handle = descriptorHandleForSize(fftSize);
}
// Creates a blank/empty frame (interpolate() must later be called).
FFTFrame::FFTFrame()
: m_FFTSize(0)
, m_log2FFTSize(0)
, m_handle(0)
{
}
// Copy constructor.
FFTFrame::FFTFrame(const FFTFrame& frame)
: m_FFTSize(frame.m_FFTSize)
, m_log2FFTSize(frame.m_log2FFTSize)
, m_handle(0)
, m_complexData(frame.m_FFTSize)
, m_realData(frame.m_FFTSize / 2)
, m_imagData(frame.m_FFTSize / 2)
{
m_handle = descriptorHandleForSize(m_FFTSize);
// Copy/setup frame data.
unsigned nbytes = sizeof(float) * (m_FFTSize / 2);
memcpy(realData(), frame.realData(), nbytes);
memcpy(imagData(), frame.imagData(), nbytes);
}
FFTFrame::~FFTFrame()
{
}
void FFTFrame::multiply(const FFTFrame& frame)
{
FFTFrame& frame1 = *this;
FFTFrame& frame2 = const_cast<FFTFrame&>(frame);
float* realP1 = frame1.realData();
float* imagP1 = frame1.imagData();
const float* realP2 = frame2.realData();
const float* imagP2 = frame2.imagData();
// Scale accounts for vecLib's peculiar scaling.
// This ensures the right scaling all the way back to inverse FFT.
// FIXME: this scaling factor will be 1.0f if the above 2.0 -> 1.0
// scaling factor is fixed.
float scale = 0.5f;
// Multiply packed DC/nyquist component.
realP1[0] *= scale * realP2[0];
imagP1[0] *= scale * imagP2[0];
// Multiply the rest, skipping packed DC/Nyquist components.
float* interleavedData1 = frame1.getUpToDateComplexData();
float* interleavedData2 = frame2.getUpToDateComplexData();
unsigned halfSize = m_FFTSize / 2;
// Complex multiply.
vcMul(halfSize - 1,
reinterpret_cast<MKL_Complex8*>(interleavedData1) + 1,
reinterpret_cast<MKL_Complex8*>(interleavedData2) + 1,
reinterpret_cast<MKL_Complex8*>(interleavedData1) + 1);
// De-interleave and scale the rest of the data.
// FIXME: find an MKL routine to do at least the scaling more efficiently.
for (unsigned i = 1; i < halfSize; ++i) {
int baseComplexIndex = 2 * i;
realP1[i] = scale * interleavedData1[baseComplexIndex];
imagP1[i] = scale * interleavedData1[baseComplexIndex + 1];
}
}
void FFTFrame::doFFT(float* data)
{
// Compute Forward transform.
MKL_LONG status = DftiComputeForward(m_handle, data, m_complexData.data());
ASSERT(DftiErrorClass(status, DFTI_NO_ERROR));
// De-interleave to separate real and complex arrays. FIXME:
// figure out if it's possible to get MKL to use split-complex
// form for 1D real-to-complex out-of-place FFTs.
int len = m_FFTSize / 2;
for (int i = 0; i < len; ++i) {
int baseComplexIndex = 2 * i;
// m_realData[0] is the DC component and m_imagData[0] the
// Nyquist component since the interleaved complex data is
// packed.
m_realData[i] = m_complexData[baseComplexIndex];
m_imagData[i] = m_complexData[baseComplexIndex + 1];
}
}
void FFTFrame::doInverseFFT(float* data)
{
// Prepare interleaved data. FIXME: figure out if it's possible to
// get MKL to use split-complex form for 1D backward
// (complex-to-real) out-of-place FFTs.
float* interleavedData = getUpToDateComplexData();
// Compute backward transform.
MKL_LONG status = DftiComputeBackward(m_handle, interleavedData, data);
ASSERT(DftiErrorClass(status, DFTI_NO_ERROR));
}
void FFTFrame::cleanup()
{
if (!descriptorHandles)
return;
for (int i = 0; i < kMaxFFTPow2Size; ++i) {
if (descriptorHandles[i]) {
MKL_LONG status = DftiFreeDescriptor(&descriptorHandles[i]);
ASSERT(DftiErrorClass(status, DFTI_NO_ERROR));
}
}
delete[] descriptorHandles;
descriptorHandles = 0;
}
float* FFTFrame::realData() const
{
return const_cast<float*>(m_realData.data());
}
float* FFTFrame::imagData() const
{
return const_cast<float*>(m_imagData.data());
}
float* FFTFrame::getUpToDateComplexData()
{
// FIXME: if we can't completely get rid of this method, SSE
// optimization could be considered if it shows up hot on profiles.
int len = m_FFTSize / 2;
for (int i = 0; i < len; ++i) {
int baseComplexIndex = 2 * i;
m_complexData[baseComplexIndex] = m_realData[i];
m_complexData[baseComplexIndex + 1] = m_imagData[i];
}
return const_cast<float*>(m_complexData.data());
}
DFTI_DESCRIPTOR_HANDLE FFTFrame::descriptorHandleForSize(unsigned fftSize)
{
if (!descriptorHandles) {
descriptorHandles = new DFTI_DESCRIPTOR_HANDLE[kMaxFFTPow2Size];
for (int i = 0; i < kMaxFFTPow2Size; ++i)
descriptorHandles[i] = 0;
}
ASSERT(fftSize);
int pow2size = static_cast<int>(log2(fftSize));
ASSERT(pow2size < kMaxFFTPow2Size);
if (!descriptorHandles[pow2size])
descriptorHandles[pow2size] = createDescriptorHandle(fftSize);
return descriptorHandles[pow2size];
}
} // namespace WebCore
#endif // ENABLE(WEB_AUDIO)
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