diff -r 000000000000 -r 6474c204b198 content/media/webaudio/blink/HRTFKernel.h
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/content/media/webaudio/blink/HRTFKernel.h	Wed Dec 31 06:09:35 2014 +0100
@@ -0,0 +1,118 @@
+/*
+ * 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.
+ */
+
+#ifndef HRTFKernel_h
+#define HRTFKernel_h
+
+#include "nsAutoPtr.h"
+#include "nsAutoRef.h"
+#include "nsTArray.h"
+#include "mozilla/FFTBlock.h"
+#include "mozilla/MemoryReporting.h"
+
+namespace WebCore {
+
+using mozilla::FFTBlock;
+
+// HRTF stands for Head-Related Transfer Function.
+// HRTFKernel is a frequency-domain representation of an impulse-response used as part of the spatialized panning system.
+// For a given azimuth / elevation angle there will be one HRTFKernel for the left ear transfer function, and one for the right ear.
+// The leading delay (average group delay) for each impulse response is extracted:
+//      m_fftFrame is the frequency-domain representation of the impulse response with the delay removed
+//      m_frameDelay is the leading delay of the original impulse response.
+class HRTFKernel {
+public:
+    // Note: this is destructive on the passed in |impulseResponse|.
+    // The |length| of |impulseResponse| must be a power of two.
+    // The size of the DFT will be |2 * length|.
+    static nsReturnRef<HRTFKernel> create(float* impulseResponse, size_t length, float sampleRate);
+
+    static nsReturnRef<HRTFKernel> create(nsAutoPtr<FFTBlock> fftFrame, float frameDelay, float sampleRate);
+
+    // Given two HRTFKernels, and an interpolation factor x: 0 -> 1, returns an interpolated HRTFKernel.
+    static nsReturnRef<HRTFKernel> createInterpolatedKernel(HRTFKernel* kernel1, HRTFKernel* kernel2, float x);
+  
+    FFTBlock* fftFrame() { return m_fftFrame.get(); }
+    
+    size_t fftSize() const { return m_fftFrame->FFTSize(); }
+    float frameDelay() const { return m_frameDelay; }
+
+    float sampleRate() const { return m_sampleRate; }
+    double nyquist() const { return 0.5 * sampleRate(); }
+
+    size_t sizeOfIncludingThis(mozilla::MallocSizeOf aMallocSizeOf) const
+    {
+        size_t amount = aMallocSizeOf(this);
+        amount += m_fftFrame->SizeOfIncludingThis(aMallocSizeOf);
+        return amount;
+    }
+
+private:
+    HRTFKernel(const HRTFKernel& other) MOZ_DELETE;
+    void operator=(const HRTFKernel& other) MOZ_DELETE;
+
+    // Note: this is destructive on the passed in |impulseResponse|.
+    HRTFKernel(float* impulseResponse, size_t fftSize, float sampleRate);
+    
+    HRTFKernel(nsAutoPtr<FFTBlock> fftFrame, float frameDelay, float sampleRate)
+        : m_fftFrame(fftFrame)
+        , m_frameDelay(frameDelay)
+        , m_sampleRate(sampleRate)
+    {
+    }
+    
+    nsAutoPtr<FFTBlock> m_fftFrame;
+    float m_frameDelay;
+    float m_sampleRate;
+};
+
+typedef nsTArray<nsAutoRef<HRTFKernel> > HRTFKernelList;
+
+} // namespace WebCore
+
+template <>
+class nsAutoRefTraits<WebCore::HRTFKernel> :
+    public nsPointerRefTraits<WebCore::HRTFKernel> {
+public:
+    static void Release(WebCore::HRTFKernel* ptr) { delete(ptr); }
+};
+
+namespace WebCore {
+
+inline nsReturnRef<HRTFKernel> HRTFKernel::create(float* impulseResponse, size_t length, float sampleRate)
+{
+    return nsReturnRef<HRTFKernel>(new HRTFKernel(impulseResponse, length, sampleRate));
+}
+
+inline nsReturnRef<HRTFKernel> HRTFKernel::create(nsAutoPtr<FFTBlock> fftFrame, float frameDelay, float sampleRate)
+{
+    return nsReturnRef<HRTFKernel>(new HRTFKernel(fftFrame, frameDelay, sampleRate));
+}
+
+} // namespace WebCore
+#endif // HRTFKernel_h