chromium/media/base/frame_rate_estimator.cc

// Copyright 2019 The Chromium Authors
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.

#include "media/base/frame_rate_estimator.h"

#include <array>

namespace media {

// Number of samples we need before we'll trust the estimate.  All samples must
// end up in the same bucket, else we won't report an FPS for the window.
// kMaxSamples is the maximum that we'll need, if we think that things are
// unstable.  kMinSamples is the minimum that we'll need to establish a
// baseline fps optimistically.
static constexpr int kMaxSamples = …;
static constexpr int kMinSamples = …;

// Size (in FPS) of our buckets, which  take on integral multiples of
// |BucketSize|.  Observed frame rates are rounded to the nearest bucket, so
// that 1.75 and 1.25 might both end up in bucket 2.
static constexpr int BucketSize = …;

namespace {

// Convert |duration| into an FPS bucket.
int ToBucket(base::TimeDelta duration) { … }

}  // namespace

FrameRateEstimator::FrameRateEstimator()
    : … { … }

FrameRateEstimator::~FrameRateEstimator() = default;

void FrameRateEstimator::AddSample(base::TimeDelta frame_duration) { … }

std::optional<int> FrameRateEstimator::ComputeFPS() { … }

void FrameRateEstimator::Reset() { … }

int FrameRateEstimator::GetRequiredSamplesForTesting() const { … }

int FrameRateEstimator::GetMinSamplesForTesting() const { … }

int FrameRateEstimator::GetMaxSamplesForTesting() const { … }

}  // namespace media