Merge WebKit at r75315: Initial merge by git.

Change-Id: I570314b346ce101c935ed22a626b48c2af266b84

1 files changed, 97 insertions, 0 deletions

diff --git a/Source/WebCore/platform/audio/ReverbConvolver.h b/Source/WebCore/platform/audio/ReverbConvolver.h
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+++ b/Source/WebCore/platform/audio/ReverbConvolver.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 ReverbConvolver_h
+#define ReverbConvolver_h
+
+#include "AudioArray.h"
+#include "FFTConvolver.h"
+#include "ReverbAccumulationBuffer.h"
+#include "ReverbConvolverStage.h"
+#include "ReverbInputBuffer.h"
+#include <wtf/OwnPtr.h>
+#include <wtf/RefCounted.h>
+#include <wtf/Threading.h>
+#include <wtf/Vector.h>
+
+namespace WebCore {
+
+class AudioChannel;
+
+class ReverbConvolver {
+public:
+    // maxFFTSize can be adjusted (from say 2048 to 32768) depending on how much precision is necessary.
+    // For certain tweaky de-convolving applications the phase errors add up quickly and lead to non-sensical results with
+    // larger FFT sizes and single-precision floats.  In these cases 2048 is a good size.
+    // If not doing multi-threaded convolution, then should not go > 8192.
+    ReverbConvolver(AudioChannel* impulseResponse, size_t renderSliceSize, size_t maxFFTSize, size_t convolverRenderPhase, bool useBackgroundThreads);
+    ~ReverbConvolver();
+
+    void process(AudioChannel* sourceChannel, AudioChannel* destinationChannel, size_t framesToProcess);
+    void reset();
+
+    size_t impulseResponseLength() const { return m_impulseResponseLength; }
+
+    ReverbInputBuffer* inputBuffer() { return &m_inputBuffer; }
+
+    bool useBackgroundThreads() const { return m_useBackgroundThreads; }
+    void backgroundThreadEntry();
+
+private:
+    Vector<OwnPtr<ReverbConvolverStage> > m_stages;
+    Vector<OwnPtr<ReverbConvolverStage> > m_backgroundStages;
+    size_t m_impulseResponseLength;
+
+    ReverbAccumulationBuffer m_accumulationBuffer;
+
+    // One or more background threads read from this input buffer which is fed from the realtime thread.
+    ReverbInputBuffer m_inputBuffer;
+
+    // We're given a rendering hint, so the FFTs can be optimized to not all occur at the same time
+    // (very bad when rendering on a real-time thread).
+    size_t m_renderSliceSize;
+
+    // First stage will be of size m_minFFTSize.  Each next stage will be twice as big until we hit m_maxFFTSize.
+    size_t m_minFFTSize;
+    size_t m_maxFFTSize;
+
+    // But don't exceed this size in the real-time thread (if we're doing background processing).
+    size_t m_maxRealtimeFFTSize;
+
+    // Background thread and synchronization
+    bool m_useBackgroundThreads;
+    ThreadIdentifier m_backgroundThread;
+    bool m_wantsToExit;
+    bool m_moreInputBuffered;
+    mutable Mutex m_backgroundThreadLock;
+    mutable ThreadCondition m_backgroundThreadCondition;
+};
+
+} // namespace WebCore
+
+#endif // ReverbConvolver_h