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authorSteve Block <steveblock@google.com>2011-05-06 11:45:16 +0100
committerSteve Block <steveblock@google.com>2011-05-12 13:44:10 +0100
commitcad810f21b803229eb11403f9209855525a25d57 (patch)
tree29a6fd0279be608e0fe9ffe9841f722f0f4e4269 /WebCore/webaudio/DelayDSPKernel.cpp
parent121b0cf4517156d0ac5111caf9830c51b69bae8f (diff)
downloadexternal_webkit-cad810f21b803229eb11403f9209855525a25d57.zip
external_webkit-cad810f21b803229eb11403f9209855525a25d57.tar.gz
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Merge WebKit at r75315: Initial merge by git.
Change-Id: I570314b346ce101c935ed22a626b48c2af266b84
Diffstat (limited to 'WebCore/webaudio/DelayDSPKernel.cpp')
-rw-r--r--WebCore/webaudio/DelayDSPKernel.cpp140
1 files changed, 0 insertions, 140 deletions
diff --git a/WebCore/webaudio/DelayDSPKernel.cpp b/WebCore/webaudio/DelayDSPKernel.cpp
deleted file mode 100644
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--- a/WebCore/webaudio/DelayDSPKernel.cpp
+++ /dev/null
@@ -1,140 +0,0 @@
-/*
- * 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 INC. 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 INC. 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 "config.h"
-
-#if ENABLE(WEB_AUDIO)
-
-#include "DelayDSPKernel.h"
-
-#include "AudioUtilities.h"
-#include <algorithm>
-
-using namespace std;
-
-const double DefaultMaxDelayTime = 1.0;
-const double SmoothingTimeConstant = 0.020; // 20ms
-
-namespace WebCore {
-
-DelayDSPKernel::DelayDSPKernel(DelayProcessor* processor)
- : AudioDSPKernel(processor)
- , m_maxDelayTime(DefaultMaxDelayTime)
- , m_writeIndex(0)
- , m_firstTime(true)
-{
- ASSERT(processor && processor->sampleRate() > 0);
- if (!processor)
- return;
-
- m_buffer.resize(static_cast<size_t>(processor->sampleRate() * DefaultMaxDelayTime));
- m_buffer.zero();
-
- m_smoothingRate = AudioUtilities::discreteTimeConstantForSampleRate(SmoothingTimeConstant, processor->sampleRate());
-}
-
-DelayDSPKernel::DelayDSPKernel(double maxDelayTime, double sampleRate)
- : AudioDSPKernel(sampleRate)
- , m_maxDelayTime(maxDelayTime)
- , m_writeIndex(0)
- , m_firstTime(true)
-{
- ASSERT(maxDelayTime > 0.0);
- if (maxDelayTime <= 0.0)
- return;
-
- size_t bufferLength = static_cast<size_t>(sampleRate * maxDelayTime);
- ASSERT(bufferLength);
- if (!bufferLength)
- return;
-
- m_buffer.resize(bufferLength);
- m_buffer.zero();
-
- m_smoothingRate = AudioUtilities::discreteTimeConstantForSampleRate(SmoothingTimeConstant, sampleRate);
-}
-
-void DelayDSPKernel::process(const float* source, float* destination, size_t framesToProcess)
-{
- size_t bufferLength = m_buffer.size();
- float* buffer = m_buffer.data();
-
- ASSERT(bufferLength);
- if (!bufferLength)
- return;
-
- ASSERT(source && destination);
- if (!source || !destination)
- return;
-
- double sampleRate = this->sampleRate();
- double delayTime = delayProcessor() ? delayProcessor()->delayTime()->value() : m_desiredDelayFrames / sampleRate;
-
- // Make sure the delay time is in a valid range.
- delayTime = min(maxDelayTime(), delayTime);
- delayTime = max(0.0, delayTime);
-
- if (m_firstTime) {
- m_currentDelayTime = delayTime;
- m_firstTime = false;
- }
-
- int n = framesToProcess;
- while (n--) {
- // Approach desired delay time.
- m_currentDelayTime += (delayTime - m_currentDelayTime) * m_smoothingRate;
-
- double desiredDelayFrames = m_currentDelayTime * sampleRate;
-
- double readPosition = m_writeIndex + bufferLength - desiredDelayFrames;
- if (readPosition > bufferLength)
- readPosition -= bufferLength;
-
- // Linearly interpolate in-between delay times.
- int readIndex1 = static_cast<int>(readPosition);
- int readIndex2 = (readIndex1 + 1) % bufferLength;
- double interpolationFactor = readPosition - readIndex1;
-
- double input = static_cast<float>(*source++);
- buffer[m_writeIndex] = static_cast<float>(input);
- m_writeIndex = (m_writeIndex + 1) % bufferLength;
-
- double sample1 = buffer[readIndex1];
- double sample2 = buffer[readIndex2];
-
- double output = (1.0 - interpolationFactor) * sample1 + interpolationFactor * sample2;
-
- *destination++ = static_cast<float>(output);
- }
-}
-
-void DelayDSPKernel::reset()
-{
- m_firstTime = true;
- m_buffer.zero();
-}
-
-} // namespace WebCore
-
-#endif // ENABLE(WEB_AUDIO)