mirror of
https://github.com/ZLMediaKit/ZLMediaKit.git
synced 2024-12-02 00:12:33 +08:00
139 lines
3.8 KiB
C++
139 lines
3.8 KiB
C++
/*
|
||
* Copyright (c) 2016 The ZLMediaKit project authors. All Rights Reserved.
|
||
*
|
||
* This file is part of ZLMediaKit(https://github.com/ZLMediaKit/ZLMediaKit).
|
||
*
|
||
* Use of this source code is governed by MIT license that can be found in the
|
||
* LICENSE file in the root of the source tree. All contributing project authors
|
||
* may be found in the AUTHORS file in the root of the source tree.
|
||
*/
|
||
|
||
#include "Nack.h"
|
||
|
||
static constexpr uint32_t kMaxNackMS = 10 * 1000;
|
||
|
||
void NackList::push_back(RtpPacket::Ptr rtp) {
|
||
auto seq = rtp->getSeq();
|
||
_nack_cache_seq.emplace_back(seq);
|
||
_nack_cache_pkt.emplace(seq, std::move(rtp));
|
||
while (get_cache_ms() > kMaxNackMS) {
|
||
//需要清除部分nack缓存
|
||
pop_front();
|
||
}
|
||
}
|
||
|
||
void NackList::for_each_nack(const FCI_NACK &nack, const function<void(const RtpPacket::Ptr &rtp)> &func) {
|
||
auto seq = nack.getPid();
|
||
for (auto bit : nack.getBitArray()) {
|
||
if (bit) {
|
||
//丢包
|
||
RtpPacket::Ptr *ptr = get_rtp(seq);
|
||
if (ptr) {
|
||
func(*ptr);
|
||
}
|
||
}
|
||
++seq;
|
||
}
|
||
}
|
||
|
||
void NackList::pop_front() {
|
||
if (_nack_cache_seq.empty()) {
|
||
return;
|
||
}
|
||
_nack_cache_pkt.erase(_nack_cache_seq.front());
|
||
_nack_cache_seq.pop_front();
|
||
}
|
||
|
||
RtpPacket::Ptr *NackList::get_rtp(uint16_t seq) {
|
||
auto it = _nack_cache_pkt.find(seq);
|
||
if (it == _nack_cache_pkt.end()) {
|
||
return nullptr;
|
||
}
|
||
return &it->second;
|
||
}
|
||
|
||
uint32_t NackList::get_cache_ms() {
|
||
if (_nack_cache_seq.size() < 2) {
|
||
return 0;
|
||
}
|
||
uint32_t back = _nack_cache_pkt[_nack_cache_seq.back()]->getStampMS();
|
||
uint32_t front = _nack_cache_pkt[_nack_cache_seq.front()]->getStampMS();
|
||
if (back > front) {
|
||
return back - front;
|
||
}
|
||
//很有可能回环了
|
||
return back + (UINT32_MAX - front);
|
||
}
|
||
|
||
////////////////////////////////////////////////////////////////////////////////////////////////
|
||
|
||
void NackContext::received(uint16_t seq) {
|
||
if (!_last_max_seq && _seq.empty()) {
|
||
_last_max_seq = seq - 1;
|
||
}
|
||
_seq.emplace(seq);
|
||
auto max_seq = *_seq.rbegin();
|
||
auto min_seq = *_seq.begin();
|
||
auto diff = max_seq - min_seq;
|
||
if (!diff) {
|
||
return;
|
||
}
|
||
|
||
if (diff > UINT16_MAX / 2) {
|
||
//回环
|
||
_seq.clear();
|
||
_last_max_seq = min_seq;
|
||
return;
|
||
}
|
||
|
||
if (_seq.size() == diff + 1 && _last_max_seq + 1 == min_seq) {
|
||
//都是连续的seq，未丢包
|
||
_seq.clear();
|
||
_last_max_seq = max_seq;
|
||
} else {
|
||
//seq不连续，有丢包
|
||
if (min_seq == _last_max_seq + 1) {
|
||
//前面部分seq是连续的，未丢包，移除之
|
||
eraseFrontSeq();
|
||
}
|
||
|
||
//有丢包，丢包从_last_max_seq开始
|
||
if (max_seq - _last_max_seq > FCI_NACK::kBitSize) {
|
||
vector<bool> vec;
|
||
vec.resize(FCI_NACK::kBitSize);
|
||
for (auto i = 0; i < FCI_NACK::kBitSize; ++i) {
|
||
vec[i] = _seq.find(_last_max_seq + i + 2) == _seq.end();
|
||
}
|
||
doNack(FCI_NACK(_last_max_seq + 1, vec));
|
||
_last_max_seq += FCI_NACK::kBitSize + 1;
|
||
if (_last_max_seq >= max_seq) {
|
||
_seq.clear();
|
||
} else {
|
||
auto it = _seq.emplace_hint(_seq.begin(), _last_max_seq);
|
||
_seq.erase(_seq.begin(), it);
|
||
}
|
||
}
|
||
}
|
||
}
|
||
|
||
void NackContext::setOnNack(onNack cb) {
|
||
_cb = std::move(cb);
|
||
}
|
||
|
||
void NackContext::doNack(const FCI_NACK &nack) {
|
||
if (_cb) {
|
||
_cb(nack);
|
||
}
|
||
}
|
||
|
||
void NackContext::eraseFrontSeq() {
|
||
//前面部分seq是连续的，未丢包，移除之
|
||
for (auto it = _seq.begin(); it != _seq.end();) {
|
||
if (*it != _last_max_seq + 1) {
|
||
//seq不连续，丢包了
|
||
break;
|
||
}
|
||
_last_max_seq = *it;
|
||
it = _seq.erase(it);
|
||
}
|
||
} |