1 files changed, 260 insertions, 0 deletions
diff --git a/WebCore/platform/audio/mkl/FFTFrameMKL.cpp b/WebCore/platform/audio/mkl/FFTFrameMKL.cpp
new file mode 100644
index 0000000..f66a485
--- /dev/null
+++ b/WebCore/platform/audio/mkl/FFTFrameMKL.cpp
@@ -0,0 +1,260 @@
+/*
+ * 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)