mirror of
https://github.com/mollyim/webrtc.git
synced 2025-05-13 22:00:47 +01:00
46ca2879e1
Bug: webrtc:8105 Change-Id: I8c68e0f270b3bd5d8da28b8334d4689064f607f6 Reviewed-on: https://webrtc-review.googlesource.com/4920 Commit-Queue: Ivo Creusen <ivoc@webrtc.org> Reviewed-by: Alex Narest <alexnarest@webrtc.org> Reviewed-by: Stefan Holmer <stefan@webrtc.org> Cr-Commit-Position: refs/heads/master@{#20205}
93 lines
4 KiB
C++
93 lines
4 KiB
C++
/*
|
|
* Copyright (c) 2014 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 MODULES_REMOTE_BITRATE_ESTIMATOR_AIMD_RATE_CONTROL_H_
|
|
#define MODULES_REMOTE_BITRATE_ESTIMATOR_AIMD_RATE_CONTROL_H_
|
|
|
|
#include "modules/remote_bitrate_estimator/include/bwe_defines.h"
|
|
#include "rtc_base/constructormagic.h"
|
|
|
|
namespace webrtc {
|
|
|
|
// A rate control implementation based on additive increases of
|
|
// bitrate when no over-use is detected and multiplicative decreases when
|
|
// over-uses are detected. When we think the available bandwidth has changes or
|
|
// is unknown, we will switch to a "slow-start mode" where we increase
|
|
// multiplicatively.
|
|
class AimdRateControl {
|
|
public:
|
|
AimdRateControl();
|
|
~AimdRateControl();
|
|
|
|
// Returns true if there is a valid estimate of the incoming bitrate, false
|
|
// otherwise.
|
|
bool ValidEstimate() const;
|
|
void SetStartBitrate(int start_bitrate_bps);
|
|
void SetMinBitrate(int min_bitrate_bps);
|
|
int64_t GetFeedbackInterval() const;
|
|
// Returns true if the bitrate estimate hasn't been changed for more than
|
|
// an RTT, or if the incoming_bitrate is less than half of the current
|
|
// estimate. Should be used to decide if we should reduce the rate further
|
|
// when over-using.
|
|
bool TimeToReduceFurther(int64_t time_now,
|
|
uint32_t incoming_bitrate_bps) const;
|
|
uint32_t LatestEstimate() const;
|
|
void SetRtt(int64_t rtt);
|
|
uint32_t Update(const RateControlInput* input, int64_t now_ms);
|
|
void SetEstimate(int bitrate_bps, int64_t now_ms);
|
|
|
|
// Returns the increase rate when used bandwidth is near the link capacity.
|
|
int GetNearMaxIncreaseRateBps() const;
|
|
// Returns the expected time between overuse signals (assuming steady state).
|
|
int GetExpectedBandwidthPeriodMs() const;
|
|
|
|
private:
|
|
// Update the target bitrate according based on, among other things,
|
|
// the current rate control state, the current target bitrate and the incoming
|
|
// bitrate. When in the "increase" state the bitrate will be increased either
|
|
// additively or multiplicatively depending on the rate control region. When
|
|
// in the "decrease" state the bitrate will be decreased to slightly below the
|
|
// incoming bitrate. When in the "hold" state the bitrate will be kept
|
|
// constant to allow built up queues to drain.
|
|
uint32_t ChangeBitrate(uint32_t current_bitrate,
|
|
const RateControlInput& input,
|
|
int64_t now_ms);
|
|
// Clamps new_bitrate_bps to within the configured min bitrate and a linear
|
|
// function of the incoming bitrate, so that the new bitrate can't grow too
|
|
// large compared to the bitrate actually being received by the other end.
|
|
uint32_t ClampBitrate(uint32_t new_bitrate_bps,
|
|
uint32_t incoming_bitrate_bps) const;
|
|
uint32_t MultiplicativeRateIncrease(int64_t now_ms, int64_t last_ms,
|
|
uint32_t current_bitrate_bps) const;
|
|
uint32_t AdditiveRateIncrease(int64_t now_ms, int64_t last_ms) const;
|
|
void UpdateChangePeriod(int64_t now_ms);
|
|
void UpdateMaxBitRateEstimate(float incoming_bit_rate_kbps);
|
|
void ChangeState(const RateControlInput& input, int64_t now_ms);
|
|
void ChangeRegion(RateControlRegion region);
|
|
|
|
uint32_t min_configured_bitrate_bps_;
|
|
uint32_t max_configured_bitrate_bps_;
|
|
uint32_t current_bitrate_bps_;
|
|
float avg_max_bitrate_kbps_;
|
|
float var_max_bitrate_kbps_;
|
|
RateControlState rate_control_state_;
|
|
RateControlRegion rate_control_region_;
|
|
int64_t time_last_bitrate_change_;
|
|
int64_t time_first_incoming_estimate_;
|
|
bool bitrate_is_initialized_;
|
|
float beta_;
|
|
int64_t rtt_;
|
|
bool in_experiment_;
|
|
bool smoothing_experiment_;
|
|
rtc::Optional<int> last_decrease_;
|
|
};
|
|
} // namespace webrtc
|
|
|
|
#endif // MODULES_REMOTE_BITRATE_ESTIMATOR_AIMD_RATE_CONTROL_H_
|