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diff --git a/Source/WebCore/platform/audio/AudioChannel.h b/Source/WebCore/platform/audio/AudioChannel.h
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+++ b/Source/WebCore/platform/audio/AudioChannel.h
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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.
+ */
+
+#ifndef AudioChannel_h
+#define AudioChannel_h
+
+#include "AudioArray.h"
+#include <wtf/Noncopyable.h>
+#include <wtf/PassOwnPtr.h>
+
+namespace WebCore {
+
+// An AudioChannel represents a buffer of non-interleaved floating-point audio samples.
+// The PCM samples are normally assumed to be in a nominal range -1.0 -> +1.0
+class AudioChannel : public Noncopyable {
+public:
+    // Memory can be externally referenced, or can be internally allocated with an AudioFloatArray.
+
+    // Reference an external buffer.
+    AudioChannel(float* storage, size_t length)
+        : m_length(length), m_rawPointer(storage) { }
+
+    // Manage storage for us.
+    explicit AudioChannel(size_t length)
+        : m_length(length)
+        , m_rawPointer(0)
+    {
+        m_memBuffer = adoptPtr(new AudioFloatArray(length));
+    }
+
+    // A "blank" audio channel -- must call set() before it's useful...
+    AudioChannel()
+        : m_length(0)
+        , m_rawPointer(0)
+    {
+    }
+
+    // Redefine the memory for this channel.
+    // storage represents external memory not managed by this object.
+    void set(float* storage, size_t length)
+    {
+        m_memBuffer.clear(); // cleanup managed storage
+        m_rawPointer = storage;
+        m_length = length;
+    }
+
+    // How many sample-frames do we contain?
+    size_t length() const { return m_length; }
+
+    // Direct access to PCM sample data
+    float* data() { return m_rawPointer ? m_rawPointer : m_memBuffer->data(); }
+    const float* data() const { return m_rawPointer ? m_rawPointer : m_memBuffer->data(); }
+
+    // Zeroes out all sample values in buffer.
+    void zero()
+    {
+        if (m_memBuffer.get())
+            m_memBuffer->zero();
+        else
+            memset(m_rawPointer, 0, sizeof(float) * m_length);
+    }
+
+    // Scales all samples by the same amount.
+    void scale(double scale);
+
+    // A simple memcpy() from the source channel
+    void copyFrom(const AudioChannel* sourceChannel);
+
+    // Copies the given range from the source channel.
+    void copyFromRange(const AudioChannel* sourceChannel, unsigned startFrame, unsigned endFrame);
+
+    // Sums (with unity gain) from the source channel.
+    void sumFrom(const AudioChannel* sourceChannel);
+
+    // Returns maximum absolute value (useful for normalization).
+    float maxAbsValue() const;
+
+private:
+    size_t m_length;
+
+    float* m_rawPointer;
+    OwnPtr<AudioFloatArray> m_memBuffer;
+};
+
+} // WebCore
+
+#endif // AudioChannel_h