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/*
* Copyright (c) 2020 The WebRTC project authors. All Rights Reserved.
*
* Use of this source code is governed by a BSD-style license
* that can be found in the LICENSE file in the root of the source
* tree. An additional intellectual property rights grant can be found
* in the file PATENTS. All contributing project authors may
* be found in the AUTHORS file in the root of the source tree.
*/
#ifndef VIDEO_ADAPTATION_OVERUSE_FRAME_DETECTOR_H_
#define VIDEO_ADAPTATION_OVERUSE_FRAME_DETECTOR_H_
#include <list>
#include <memory>
#include <optional>
#include "api/environment/environment.h"
#include "api/field_trials_view.h"
#include "api/sequence_checker.h"
#include "api/task_queue/task_queue_base.h"
#include "rtc_base/experiments/field_trial_parser.h"
#include "rtc_base/numerics/exp_filter.h"
#include "rtc_base/system/no_unique_address.h"
#include "rtc_base/task_utils/repeating_task.h"
#include "rtc_base/thread_annotations.h"
#include "video/video_stream_encoder_observer.h"
namespace webrtc {
class VideoFrame;
struct CpuOveruseOptions {
// Threshold for triggering overuse.
int high_encode_usage_threshold_percent = 85;
// Threshold for triggering underuse.
// Note that we make the interval 2x+epsilon wide, since libyuv scaling steps
// are close to that (when squared). This wide interval makes sure that
// scaling up or down does not jump all the way across the interval.
int low_encode_usage_threshold_percent =
(high_encode_usage_threshold_percent - 1) / 2;
// General settings.
// The maximum allowed interval between two frames before resetting
// estimations.
int frame_timeout_interval_ms = 1500;
// The minimum number of frames required.
int min_frame_samples = 120;
// The number of initial process times required before
// triggering an overuse/underuse.
int min_process_count = 3;
// The number of consecutive checks above the high threshold before triggering
// an overuse.
int high_threshold_consecutive_count = 2;
// New estimator enabled if this is set non-zero.
int filter_time_ms = 0; // Time constant for averaging
};
class OveruseFrameDetectorObserverInterface {
public:
// Called to signal that we can handle larger or more frequent frames.
virtual void AdaptUp() = 0;
// Called to signal that the source should reduce the resolution or framerate.
virtual void AdaptDown() = 0;
protected:
virtual ~OveruseFrameDetectorObserverInterface() {}
};
// Use to detect system overuse based on the send-side processing time of
// incoming frames. All methods must be called on a single task queue but it can
// be created and destroyed on an arbitrary thread.
// OveruseFrameDetector::StartCheckForOveruse must be called to periodically
// check for overuse.
class OveruseFrameDetector {
public:
OveruseFrameDetector(const Environment& env,
CpuOveruseMetricsObserver* metrics_observer);
virtual ~OveruseFrameDetector();
OveruseFrameDetector(const OveruseFrameDetector&) = delete;
OveruseFrameDetector& operator=(const OveruseFrameDetector&) = delete;
// Start to periodically check for overuse.
void StartCheckForOveruse(
TaskQueueBase* task_queue_base,
const CpuOveruseOptions& options,
OveruseFrameDetectorObserverInterface* overuse_observer);
// StopCheckForOveruse must be called before destruction if
// StartCheckForOveruse has been called.
void StopCheckForOveruse();
// Defines the current maximum framerate targeted by the capturer. This is
// used to make sure the encode usage percent doesn't drop unduly if the
// capturer has quiet periods (for instance caused by screen capturers with
// variable capture rate depending on content updates), otherwise we might
// experience adaptation toggling.
virtual void OnTargetFramerateUpdated(int framerate_fps);
// Called for each captured frame.
void FrameCaptured(const VideoFrame& frame, int64_t time_when_first_seen_us);
// Called for each sent frame.
void FrameSent(uint32_t timestamp,
int64_t time_sent_in_us,
int64_t capture_time_us,
std::optional<int> encode_duration_us);
// Interface for cpu load estimation. Intended for internal use only.
class ProcessingUsage {
public:
virtual void Reset() = 0;
virtual void SetMaxSampleDiffMs(float diff_ms) = 0;
virtual void FrameCaptured(const VideoFrame& frame,
int64_t time_when_first_seen_us,
int64_t last_capture_time_us) = 0;
// Returns encode_time in us, if there's a new measurement.
virtual std::optional<int> FrameSent(
// These two argument used by old estimator.
uint32_t timestamp,
int64_t time_sent_in_us,
// And these two by the new estimator.
int64_t capture_time_us,
std::optional<int> encode_duration_us) = 0;
virtual int Value() = 0;
virtual ~ProcessingUsage() = default;
};
protected:
// Protected for test purposes.
void CheckForOveruse(OveruseFrameDetectorObserverInterface* overuse_observer);
void SetOptions(const CpuOveruseOptions& options);
CpuOveruseOptions options_;
private:
void EncodedFrameTimeMeasured(int encode_duration_ms);
bool IsOverusing(int encode_usage_percent);
bool IsUnderusing(int encode_usage_percent, int64_t time_now);
bool FrameTimeoutDetected(int64_t now) const;
bool FrameSizeChanged(int num_pixels) const;
void ResetAll(int num_pixels);
static std::unique_ptr<ProcessingUsage> CreateProcessingUsage(
const FieldTrialsView& field_trials,
const CpuOveruseOptions& options);
const Environment env_;
RTC_NO_UNIQUE_ADDRESS SequenceChecker task_checker_;
// Owned by the task queue from where StartCheckForOveruse is called.
RepeatingTaskHandle check_overuse_task_ RTC_GUARDED_BY(task_checker_);
// Stats metrics.
CpuOveruseMetricsObserver* const metrics_observer_;
std::optional<int> encode_usage_percent_ RTC_GUARDED_BY(task_checker_);
int64_t num_process_times_ RTC_GUARDED_BY(task_checker_);
int64_t last_capture_time_us_ RTC_GUARDED_BY(task_checker_);
// Number of pixels of last captured frame.
int num_pixels_ RTC_GUARDED_BY(task_checker_);
int max_framerate_ RTC_GUARDED_BY(task_checker_);
int64_t last_overuse_time_ms_ RTC_GUARDED_BY(task_checker_);
int checks_above_threshold_ RTC_GUARDED_BY(task_checker_);
int num_overuse_detections_ RTC_GUARDED_BY(task_checker_);
int64_t last_rampup_time_ms_ RTC_GUARDED_BY(task_checker_);
bool in_quick_rampup_ RTC_GUARDED_BY(task_checker_);
int current_rampup_delay_ms_ RTC_GUARDED_BY(task_checker_);
std::unique_ptr<ProcessingUsage> usage_ RTC_PT_GUARDED_BY(task_checker_);
// If set by field trial, overrides CpuOveruseOptions::filter_time_ms.
FieldTrialOptional<TimeDelta> filter_time_constant_{"tau"};
};
} // namespace webrtc
#endif // VIDEO_ADAPTATION_OVERUSE_FRAME_DETECTOR_H_