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/*
* 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_MODULE_H_
#define MODULES_VIDEO_CODING_NACK_MODULE_H_
#include <map>
#include <set>
#include <vector>
#include "modules/include/module.h"
#include "modules/include/module_common_types.h"
#include "modules/video_coding/histogram.h"
#include "rtc_base/criticalsection.h"
#include "rtc_base/numerics/sequence_number_util.h"
#include "rtc_base/thread_annotations.h"
#include "system_wrappers/include/clock.h"
namespace webrtc {
class NackModule : public Module {
public:
NackModule(Clock* clock,
NackSender* nack_sender,
KeyFrameRequestSender* keyframe_request_sender);
int OnReceivedPacket(uint16_t seq_num, bool is_keyframe);
void ClearUpTo(uint16_t seq_num);
void UpdateRtt(int64_t rtt_ms);
void Clear();
// Module implementation
int64_t TimeUntilNextProcess() override;
void Process() override;
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);
uint16_t seq_num;
uint16_t send_at_seq_num;
int64_t sent_at_time;
int retries;
};
void AddPacketsToNack(uint16_t seq_num_start, uint16_t seq_num_end)
RTC_EXCLUSIVE_LOCKS_REQUIRED(crit_);
// Removes packets from the nack list until the next keyframe. Returns true
// if packets were removed.
bool RemovePacketsUntilKeyFrame() RTC_EXCLUSIVE_LOCKS_REQUIRED(crit_);
std::vector<uint16_t> GetNackBatch(NackFilterOptions options)
RTC_EXCLUSIVE_LOCKS_REQUIRED(crit_);
// Update the reordering distribution.
void UpdateReorderingStatistics(uint16_t seq_num)
RTC_EXCLUSIVE_LOCKS_REQUIRED(crit_);
// 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(crit_);
rtc::CriticalSection crit_;
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(crit_);
std::set<uint16_t, DescendingSeqNumComp<uint16_t>> keyframe_list_
RTC_GUARDED_BY(crit_);
video_coding::Histogram reordering_histogram_ RTC_GUARDED_BY(crit_);
bool initialized_ RTC_GUARDED_BY(crit_);
int64_t rtt_ms_ RTC_GUARDED_BY(crit_);
uint16_t newest_seq_num_ RTC_GUARDED_BY(crit_);
// Only touched on the process thread.
int64_t next_process_time_ms_;
};
} // namespace webrtc
#endif // MODULES_VIDEO_CODING_NACK_MODULE_H_
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