141 lines
4.9 KiB
C++
141 lines
4.9 KiB
C++
/*
|
|
* Copyright (c) 2016 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_VIDEO_CODING_NACK_MODULE2_H_
|
|
#define MODULES_VIDEO_CODING_NACK_MODULE2_H_
|
|
|
|
#include <stdint.h>
|
|
|
|
#include <map>
|
|
#include <set>
|
|
#include <vector>
|
|
|
|
#include "api/sequence_checker.h"
|
|
#include "api/units/time_delta.h"
|
|
#include "modules/include/module_common_types.h"
|
|
#include "modules/video_coding/histogram.h"
|
|
#include "rtc_base/numerics/sequence_number_util.h"
|
|
#include "rtc_base/task_queue.h"
|
|
#include "rtc_base/task_utils/pending_task_safety_flag.h"
|
|
#include "rtc_base/task_utils/repeating_task.h"
|
|
#include "rtc_base/thread_annotations.h"
|
|
#include "system_wrappers/include/clock.h"
|
|
|
|
namespace webrtc {
|
|
|
|
// TODO(bugs.webrtc.org/11594): This class no longer implements the Module
|
|
// interface and therefore "NackModule" may not be a descriptive name anymore.
|
|
// Consider renaming to e.g. NackTracker or NackRequester.
|
|
class NackModule2 final {
|
|
public:
|
|
static constexpr TimeDelta kUpdateInterval = TimeDelta::Millis(20);
|
|
|
|
NackModule2(TaskQueueBase* current_queue,
|
|
Clock* clock,
|
|
NackSender* nack_sender,
|
|
KeyFrameRequestSender* keyframe_request_sender,
|
|
TimeDelta update_interval = kUpdateInterval);
|
|
~NackModule2();
|
|
|
|
int OnReceivedPacket(uint16_t seq_num, bool is_keyframe);
|
|
int OnReceivedPacket(uint16_t seq_num, bool is_keyframe, bool is_recovered);
|
|
|
|
void ClearUpTo(uint16_t seq_num);
|
|
void UpdateRtt(int64_t rtt_ms);
|
|
|
|
private:
|
|
// Which fields to consider when deciding which packet to nack in
|
|
// GetNackBatch.
|
|
enum NackFilterOptions { kSeqNumOnly, kTimeOnly, kSeqNumAndTime };
|
|
|
|
// This class holds the sequence number of the packet that is in the nack list
|
|
// as well as the meta data about when it should be nacked and how many times
|
|
// we have tried to nack this packet.
|
|
struct NackInfo {
|
|
NackInfo();
|
|
NackInfo(uint16_t seq_num,
|
|
uint16_t send_at_seq_num,
|
|
int64_t created_at_time);
|
|
|
|
uint16_t seq_num;
|
|
uint16_t send_at_seq_num;
|
|
int64_t created_at_time;
|
|
int64_t sent_at_time;
|
|
int retries;
|
|
};
|
|
|
|
struct BackoffSettings {
|
|
BackoffSettings(TimeDelta min_retry, TimeDelta max_rtt, double base);
|
|
static absl::optional<BackoffSettings> ParseFromFieldTrials();
|
|
|
|
// Min time between nacks.
|
|
const TimeDelta min_retry_interval;
|
|
// Upper bound on link-delay considered for exponential backoff.
|
|
const TimeDelta max_rtt;
|
|
// Base for the exponential backoff.
|
|
const double base;
|
|
};
|
|
|
|
void AddPacketsToNack(uint16_t seq_num_start, uint16_t seq_num_end)
|
|
RTC_EXCLUSIVE_LOCKS_REQUIRED(worker_thread_);
|
|
|
|
// Removes packets from the nack list until the next keyframe. Returns true
|
|
// if packets were removed.
|
|
bool RemovePacketsUntilKeyFrame()
|
|
RTC_EXCLUSIVE_LOCKS_REQUIRED(worker_thread_);
|
|
std::vector<uint16_t> GetNackBatch(NackFilterOptions options)
|
|
RTC_EXCLUSIVE_LOCKS_REQUIRED(worker_thread_);
|
|
|
|
// Update the reordering distribution.
|
|
void UpdateReorderingStatistics(uint16_t seq_num)
|
|
RTC_EXCLUSIVE_LOCKS_REQUIRED(worker_thread_);
|
|
|
|
// Returns how many packets we have to wait in order to receive the packet
|
|
// with probability |probabilty| or higher.
|
|
int WaitNumberOfPackets(float probability) const
|
|
RTC_EXCLUSIVE_LOCKS_REQUIRED(worker_thread_);
|
|
|
|
TaskQueueBase* const worker_thread_;
|
|
|
|
// Used to regularly call SendNack if needed.
|
|
RepeatingTaskHandle repeating_task_ RTC_GUARDED_BY(worker_thread_);
|
|
const TimeDelta update_interval_;
|
|
|
|
Clock* const clock_;
|
|
NackSender* const nack_sender_;
|
|
KeyFrameRequestSender* const keyframe_request_sender_;
|
|
|
|
// TODO(philipel): Some of the variables below are consistently used on a
|
|
// known thread (e.g. see |initialized_|). Those probably do not need
|
|
// synchronized access.
|
|
std::map<uint16_t, NackInfo, DescendingSeqNumComp<uint16_t>> nack_list_
|
|
RTC_GUARDED_BY(worker_thread_);
|
|
std::set<uint16_t, DescendingSeqNumComp<uint16_t>> keyframe_list_
|
|
RTC_GUARDED_BY(worker_thread_);
|
|
std::set<uint16_t, DescendingSeqNumComp<uint16_t>> recovered_list_
|
|
RTC_GUARDED_BY(worker_thread_);
|
|
video_coding::Histogram reordering_histogram_ RTC_GUARDED_BY(worker_thread_);
|
|
bool initialized_ RTC_GUARDED_BY(worker_thread_);
|
|
int64_t rtt_ms_ RTC_GUARDED_BY(worker_thread_);
|
|
uint16_t newest_seq_num_ RTC_GUARDED_BY(worker_thread_);
|
|
|
|
// Adds a delay before send nack on packet received.
|
|
const int64_t send_nack_delay_ms_;
|
|
|
|
const absl::optional<BackoffSettings> backoff_settings_;
|
|
|
|
// Used to signal destruction to potentially pending tasks.
|
|
ScopedTaskSafety task_safety_;
|
|
};
|
|
|
|
} // namespace webrtc
|
|
|
|
#endif // MODULES_VIDEO_CODING_NACK_MODULE2_H_
|