重写jitter buffer长度控制算法,提高webrtc/rtp抗丢包能力

This commit is contained in:
ziyue 2023-03-06 20:43:07 +08:00
parent d6e9a4fb90
commit d05c9d5f51
3 changed files with 51 additions and 43 deletions

View File

@ -114,7 +114,7 @@ void RtpTrack::setNtpStamp(uint32_t rtp_stamp, uint64_t ntp_stamp_ms) {
} }
} }
void RtpTrack::setPT(uint8_t pt){ void RtpTrack::setPayloadType(uint8_t pt) {
_pt = pt; _pt = pt;
} }

View File

@ -18,19 +18,18 @@
#include "Extension/Frame.h" #include "Extension/Frame.h"
// for NtpStamp // for NtpStamp
#include "Common/Stamp.h" #include "Common/Stamp.h"
#include "Util/TimeTicker.h"
namespace mediakit { namespace mediakit {
template<typename T, typename SEQ = uint16_t, size_t kMax = 1024, size_t kMin = 32> template<typename T, typename SEQ = uint16_t>
class PacketSortor { class PacketSortor {
public: public:
static constexpr SEQ SEQ_MAX = (std::numeric_limits<SEQ>::max)(); static constexpr SEQ SEQ_MAX = (std::numeric_limits<SEQ>::max)();
PacketSortor() = default; PacketSortor() = default;
~PacketSortor() = default; ~PacketSortor() = default;
void setOnSort(std::function<void(SEQ seq, T packet)> cb) { void setOnSort(std::function<void(SEQ seq, T packet)> cb) { _cb = std::move(cb); }
_cb = std::move(cb);
}
/** /**
* *
@ -38,23 +37,18 @@ public:
void clear() { void clear() {
_started = false; _started = false;
_seq_cycle_count = 0; _seq_cycle_count = 0;
_max_sort_size = kMin;
_pkt_sort_cache_map.clear(); _pkt_sort_cache_map.clear();
} }
/** /**
* *
*/ */
size_t getJitterSize() const { size_t getJitterSize() const { return _pkt_sort_cache_map.size(); }
return _pkt_sort_cache_map.size();
}
/** /**
* seq回环次数 * seq回环次数
*/ */
size_t getCycleCount() const{ size_t getCycleCount() const { return _seq_cycle_count; }
return _seq_cycle_count;
}
/** /**
* *
@ -73,51 +67,66 @@ public:
return; return;
} }
if (seq < _last_seq_out && _last_seq_out != SEQ_MAX && seq < kMax && _last_seq_out > SEQ_MAX - kMax) { if (seq < _last_seq_out && _last_seq_out != SEQ_MAX && seq < 1024 && _last_seq_out > SEQ_MAX - 1024) {
// seq回环,清空回环前缓存 // seq回环,清空回环前缓存
flush(); flush();
_last_seq_out = SEQ_MAX; _last_seq_out = SEQ_MAX;
_pkt_sort_cache_map.emplace(seq, std::move(packet));
++_seq_cycle_count; ++_seq_cycle_count;
sortPacket(seq, std::move(packet));
return; return;
} }
if (seq <= _last_seq_out && _last_seq_out != SEQ_MAX) { if (seq <= _last_seq_out && _last_seq_out != SEQ_MAX) {
// 这个回退包已经不再等待 // 这个回退包已经不再等待
setBufferSize(seq);
return; return;
} }
_pkt_sort_cache_map.emplace(seq, std::move(packet)); _pkt_sort_cache_map.emplace(seq, std::move(packet));
auto max_seq = _pkt_sort_cache_map.rbegin()->first; auto it_min = _pkt_sort_cache_map.begin();
auto min_seq = _pkt_sort_cache_map.begin()->first; auto it_max = _pkt_sort_cache_map.rbegin();
auto diff = max_seq - min_seq; if (it_max->first - it_min->first > (SEQ_MAX >> 1)) {
if (diff > (SEQ_MAX >> 1)) {
// 回环后收到回环前的大值seq, 忽略掉 // 回环后收到回环前的大值seq, 忽略掉
_pkt_sort_cache_map.erase(max_seq); _pkt_sort_cache_map.erase((++it_max).base());
return; return;
} }
if (min_seq == static_cast<SEQ>(_last_seq_out + 1) && _pkt_sort_cache_map.size() == (size_t)diff + 1) { tryFlushFrontPacket();
// 都是连续的seq, 未丢包
flush(); if (_pkt_sort_cache_map.size() > _max_buffer_size || (_ticker.elapsedTime() > _max_buffer_ms && !_pkt_sort_cache_map.empty())) {
} else { // buffer太长强行减小
// seq不连续有丢包 WarnL << "packet dropped: " << static_cast<SEQ>(_last_seq_out + 1) << " -> "
if (_pkt_sort_cache_map.size() >= _max_sort_size) { << static_cast<SEQ>(_pkt_sort_cache_map.begin()->first - 1)
//buffer太长强行减小 << ", jitter buffer size: " << _pkt_sort_cache_map.size()
popIterator(_pkt_sort_cache_map.begin()); << ", jitter buffer ms: " << _ticker.elapsedTime();
} popIterator(_pkt_sort_cache_map.begin());
} }
} }
void flush(){ void flush() {
//清空缓存 // 清空缓存
while (!_pkt_sort_cache_map.empty()) { while (!_pkt_sort_cache_map.empty()) {
popIterator(_pkt_sort_cache_map.begin()); popIterator(_pkt_sort_cache_map.begin());
} }
} }
private: private:
void tryFlushFrontPacket() {
while (!_pkt_sort_cache_map.empty()) {
auto it = _pkt_sort_cache_map.begin();
auto next_seq = static_cast<SEQ>(_last_seq_out + 1);
if (it->first < next_seq) {
_pkt_sort_cache_map.erase(it);
continue;
}
if (it->first == next_seq) {
// 连续的seq
popIterator(it);
continue;
}
break;
}
}
void popIterator(typename std::map<SEQ, T>::iterator it) { void popIterator(typename std::map<SEQ, T>::iterator it) {
auto seq = it->first; auto seq = it->first;
auto data = std::move(it->second); auto data = std::move(it->second);
@ -128,22 +137,21 @@ private:
void output(SEQ seq, T packet) { void output(SEQ seq, T packet) {
_last_seq_out = seq; _last_seq_out = seq;
_cb(seq, std::move(packet)); _cb(seq, std::move(packet));
} _ticker.resetTime();
void setBufferSize(SEQ seq) {
auto next_seq = static_cast<SEQ>(_last_seq_out + 1);
auto min_seq = _pkt_sort_cache_map.empty() ? next_seq : _pkt_sort_cache_map.begin()->first;
_max_sort_size = MAX(std::min<SEQ>(_pkt_sort_cache_map.size() + min_seq - seq, kMax), kMin);
} }
private: private:
bool _started = false; bool _started = false;
//排序缓存最大保存数据长度,单位毫秒
size_t _max_buffer_ms = 1000;
//排序缓存最大保存数据个数
size_t _max_buffer_size = 1024;
//记录上次output至今的时间
toolkit::Ticker _ticker;
//下次应该输出的SEQ //下次应该输出的SEQ
SEQ _last_seq_out = 0; SEQ _last_seq_out = 0;
//seq回环次数计数 //seq回环次数计数
size_t _seq_cycle_count = 0; size_t _seq_cycle_count = 0;
//排序缓存长度
size_t _max_sort_size = kMin;
//pkt排序缓存根据seq排序 //pkt排序缓存根据seq排序
std::map<SEQ, T> _pkt_sort_cache_map; std::map<SEQ, T> _pkt_sort_cache_map;
//回调 //回调
@ -166,7 +174,7 @@ public:
uint32_t getSSRC() const; uint32_t getSSRC() const;
RtpPacket::Ptr inputRtp(TrackType type, int sample_rate, uint8_t *ptr, size_t len); RtpPacket::Ptr inputRtp(TrackType type, int sample_rate, uint8_t *ptr, size_t len);
void setNtpStamp(uint32_t rtp_stamp, uint64_t ntp_stamp_ms); void setNtpStamp(uint32_t rtp_stamp, uint64_t ntp_stamp_ms);
void setPT(uint8_t pt); void setPayloadType(uint8_t pt);
protected: protected:
virtual void onRtpSorted(RtpPacket::Ptr rtp) {} virtual void onRtpSorted(RtpPacket::Ptr rtp) {}
@ -244,9 +252,9 @@ public:
_track[index].setNtpStamp(rtp_stamp, ntp_stamp_ms); _track[index].setNtpStamp(rtp_stamp, ntp_stamp_ms);
} }
void setPT(int index, uint8_t pt){ void setPayloadType(int index, uint8_t pt){
assert(index < kCount && index >= 0); assert(index < kCount && index >= 0);
_track[index].setPT(pt); _track[index].setPayloadType(pt);
} }
void clear() { void clear() {

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@ -225,7 +225,7 @@ void RtspPlayer::handleResDESCRIBE(const Parser& parser) {
_rtcp_context.clear(); _rtcp_context.clear();
for (auto &track : _sdp_track) { for (auto &track : _sdp_track) {
if(track->_pt != 0xff){ if(track->_pt != 0xff){
setPT(_rtcp_context.size(),track->_pt); setPayloadType(_rtcp_context.size(),track->_pt);
} }
_rtcp_context.emplace_back(std::make_shared<RtcpContextForRecv>()); _rtcp_context.emplace_back(std::make_shared<RtcpContextForRecv>());
} }