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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.
*
* 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.
*/
#ifndef AudioUtilities_h
#define AudioUtilities_h
#include "platform/PlatformExport.h"
#include "wtf/build_config.h"
#include <cstddef>
namespace blink {
namespace AudioUtilities {
// Rendering quantum size. This is how many frames are processed at a time for
// each node in the audio graph.
static const unsigned kRenderQuantumFrames = 128;
// Standard functions for converting to and from decibel values from linear.
PLATFORM_EXPORT float linearToDecibels(float);
PLATFORM_EXPORT float decibelsToLinear(float);
// timeConstant is the time it takes a first-order linear time-invariant system
// to reach the value 1 - 1/e (around 63.2%) given a step input response.
// discreteTimeConstantForSampleRate() will return the discrete time-constant
// for the specific sampleRate.
PLATFORM_EXPORT double discreteTimeConstantForSampleRate(double timeConstant,
double sampleRate);
// Convert the time to a sample frame at the given sample rate.
PLATFORM_EXPORT size_t timeToSampleFrame(double time, double sampleRate);
// Check that |sampleRate| is a valid rate for AudioBuffers.
PLATFORM_EXPORT bool isValidAudioBufferSampleRate(float sampleRate);
// Return max/min sample rate supported by AudioBuffers.
PLATFORM_EXPORT float minAudioBufferSampleRate();
PLATFORM_EXPORT float maxAudioBufferSampleRate();
// Check to see if x is a power of two. If x == 0, returns false.
PLATFORM_EXPORT bool isPowerOfTwo(size_t x);
} // namespace AudioUtilities
} // namespace blink
#endif // AudioUtilities_h
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