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diff --git a/dom/media/webaudio/blink/HRTFKernel.cpp b/dom/media/webaudio/blink/HRTFKernel.cpp
new file mode 100644
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+++ b/dom/media/webaudio/blink/HRTFKernel.cpp
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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.
+ */
+
+#include "HRTFKernel.h"
+namespace WebCore {
+
+// Takes the input audio channel |impulseP| as an input impulse response and
+// calculates the average group delay. This represents the initial delay before
+// the most energetic part of the impulse response. The sample-frame delay is
+// removed from the |impulseP| impulse response, and this value  is returned.
+// The |length| of the passed in |impulseP| must be must be a power of 2.
+static float extractAverageGroupDelay(float* impulseP, size_t length) {
+  // Check for power-of-2.
+  MOZ_ASSERT(length && (length & (length - 1)) == 0);
+
+  FFTBlock estimationFrame(length);
+  estimationFrame.PerformFFT(impulseP);
+
+  float frameDelay =
+      static_cast<float>(estimationFrame.ExtractAverageGroupDelay());
+  estimationFrame.GetInverse(impulseP);
+
+  return frameDelay;
+}
+
+HRTFKernel::HRTFKernel(float* impulseResponse, size_t length, float sampleRate)
+    : m_frameDelay(0), m_sampleRate(sampleRate) {
+  AlignedTArray<float> buffer;
+  // copy to a 32-byte aligned buffer
+  if (((uintptr_t)impulseResponse & 31) != 0) {
+    buffer.SetLength(length);
+    mozilla::PodCopy(buffer.Elements(), impulseResponse, length);
+    impulseResponse = buffer.Elements();
+  }
+
+  // Determine the leading delay (average group delay) for the response.
+  m_frameDelay = extractAverageGroupDelay(impulseResponse, length);
+
+  // The FFT size (with zero padding) needs to be twice the response length
+  // in order to do proper convolution.
+  unsigned fftSize = 2 * length;
+
+  // Quick fade-out (apply window) at truncation point
+  // because the impulse response has been truncated.
+  unsigned numberOfFadeOutFrames = static_cast<unsigned>(
+      sampleRate / 4410);  // 10 sample-frames @44.1KHz sample-rate
+  MOZ_ASSERT(numberOfFadeOutFrames < length);
+  if (numberOfFadeOutFrames < length) {
+    for (unsigned i = length - numberOfFadeOutFrames; i < length; ++i) {
+      float x =
+          1.0f - static_cast<float>(i - (length - numberOfFadeOutFrames)) /
+                     numberOfFadeOutFrames;
+      impulseResponse[i] *= x;
+    }
+  }
+
+  m_fftFrame = mozilla::MakeUnique<FFTBlock>(fftSize);
+  m_fftFrame->PadAndMakeScaledDFT(impulseResponse, length);
+}
+
+// Interpolates two kernels with x: 0 -> 1 and returns the result.
+nsReturnRef<HRTFKernel> HRTFKernel::createInterpolatedKernel(
+    HRTFKernel* kernel1, HRTFKernel* kernel2, float x) {
+  MOZ_ASSERT(kernel1 && kernel2);
+  if (!kernel1 || !kernel2) return nsReturnRef<HRTFKernel>();
+
+  MOZ_ASSERT(x >= 0.0 && x < 1.0);
+  x = mozilla::clamped(x, 0.0f, 1.0f);
+
+  float sampleRate1 = kernel1->sampleRate();
+  float sampleRate2 = kernel2->sampleRate();
+  MOZ_ASSERT(sampleRate1 == sampleRate2);
+  if (sampleRate1 != sampleRate2) return nsReturnRef<HRTFKernel>();
+
+  float frameDelay =
+      (1 - x) * kernel1->frameDelay() + x * kernel2->frameDelay();
+
+  UniquePtr<FFTBlock> interpolatedFrame(FFTBlock::CreateInterpolatedBlock(
+      *kernel1->fftFrame(), *kernel2->fftFrame(), x));
+  return HRTFKernel::create(std::move(interpolatedFrame), frameDelay,
+                            sampleRate1);
+}
+
+}  // namespace WebCore