Files
crossdesk/src/qos/congestion_control_feedback_generator.h
2025-01-08 17:30:13 +08:00

67 lines
2.1 KiB
C++

/*
* @Author: DI JUNKUN
* @Date: 2024-12-18
* Copyright (c) 2024 by DI JUNKUN, All Rights Reserved.
*/
#ifndef _CONGESTION_CONTROL_FEEDBACK_GENERATOR_H_
#define _CONGESTION_CONTROL_FEEDBACK_GENERATOR_H_
#include <optional>
#include <vector>
#include "congestion_control_feedback_tracker.h"
#include "rtcp_packet.h"
#include "rtp_packet_received.h"
class CongestionControlFeedbackGenerator {
public:
CongestionControlFeedbackGenerator(RtcpSender feedback_sender);
~CongestionControlFeedbackGenerator() = default;
void OnReceivedPacket(RtpPacketReceived& packet);
void OnSendBandwidthEstimateChanged(int64_t estimate);
int64_t Process(int64_t now_ms);
void SetTransportOverhead(int64_t overhead_per_packet);
private:
int64_t NextFeedbackTime() const;
void SendFeedback(int64_t now_ms);
void CalculateNextPossibleSendTime(int64_t feedback_size, int64_t now_ms);
const RtcpSender rtcp_sender_;
private:
// Feedback should not use more than 5% of the configured send bandwidth
// estimate. Min and max duration between feedback is configurable using field
// trials, but per default, min is 25ms and max is 250ms.
// If possible, given the other constraints, feedback will be sent when a
// packet with marker bit is received in order to provide feedback as soon as
// possible after receiving a complete video frame. If no packet with marker
// bit is received, feedback can be delayed up to 25ms after the first packet
// since the last sent feedback. On good networks, this means that a sender
// may receive feedback for every sent frame.
int64_t min_time_between_feedback_ = 25;
int64_t max_time_between_feedback_ = 250;
int64_t max_time_to_wait_for_packet_with_marker_ = 25;
int64_t max_feedback_rate_ = 1000; // kbps
int64_t packet_overhead_ = 0;
int64_t send_rate_debt_ = 0;
std::map</*ssrc=*/uint32_t, CongestionControlFeedbackTracker>
feedback_trackers_;
std::optional<int64_t> first_arrival_time_since_feedback_;
int64_t next_possible_feedback_send_time_ = 0;
int64_t last_feedback_sent_time_ = 0;
bool marker_bit_seen_ = false;
};
#endif