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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 THIRD_PARTY_BLINK_RENDERER_PLATFORM_AUDIO_AUDIO_UTILITIES_H_
#define THIRD_PARTY_BLINK_RENDERER_PLATFORM_AUDIO_AUDIO_UTILITIES_H_
#include <cstddef>
#include "base/time/time.h"
#include "third_party/blink/public/common/mediastream/media_devices.h"
#include "third_party/blink/public/platform/web_audio_latency_hint.h"
#include "third_party/blink/public/platform/web_audio_sink_descriptor.h"
#include "third_party/blink/renderer/platform/platform_export.h"
namespace blink::audio_utilities {
// How to do rounding when converting time to sample frame.
enum SampleFrameRounding {
// Round to nearest integer
kRoundToNearest,
// Round down
kRoundDown,
// Round up
kRoundUp
};
// 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 time_constant,
double sample_rate);
// Convert the time to a sample frame at the given sample rate.
PLATFORM_EXPORT size_t
TimeToSampleFrame(double time,
double sample_rate,
enum SampleFrameRounding rounding = kRoundToNearest);
// Calculate a buffer duration given the number of frames and a sample rate.
// The only reason we have it here is because it takes sample_rate as float.
// Otherwise, media::AudioTimestampHelper::FramesToTime would be just fine.
PLATFORM_EXPORT
base::TimeDelta FramesToTime(int64_t frames, float sample_rate);
// Check that |sampleRate| is a valid rate for AudioBuffers.
PLATFORM_EXPORT bool IsValidAudioBufferSampleRate(float sample_rate);
// Return max/min sample rate supported by AudioBuffers.
PLATFORM_EXPORT float MinAudioBufferSampleRate();
PLATFORM_EXPORT float MaxAudioBufferSampleRate();
PLATFORM_EXPORT const std::string GetSinkIdForTracing(
blink::WebAudioSinkDescriptor sink_descriptor);
PLATFORM_EXPORT const std::string GetSinkInfoForTracing(
blink::WebAudioSinkDescriptor sink_descriptor,
blink::WebAudioLatencyHint latency_hint,
int channel_count,
float sample_rate,
int buffer_size);
PLATFORM_EXPORT const std::string GetDeviceEnumerationForTracing(
const Vector<WebMediaDeviceInfo>& device_infos);
} // namespace blink::audio_utilities
#endif // THIRD_PARTY_BLINK_RENDERER_PLATFORM_AUDIO_AUDIO_UTILITIES_H_
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