mirror of
https://github.com/ZLMediaKit/ZLMediaKit.git
synced 2024-10-06 20:23:43 +08:00
112 lines
3.4 KiB
C++
112 lines
3.4 KiB
C++
/*
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* Copyright (c) 2021 The ZLMediaKit project authors. All Rights Reserved.
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*
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* This file is part of ZLMediaKit(https://github.com/xia-chu/ZLMediaKit).
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*
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* Use of this source code is governed by MIT license that can be found in the
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* LICENSE file in the root of the source tree. All contributing project authors
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* may be found in the AUTHORS file in the root of the source tree.
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*/
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#include "TwccContext.h"
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#include "Rtcp/RtcpFCI.h"
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using namespace mediakit;
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enum class ExtSeqStatus : int {
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normal = 0,
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looped,
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jumped,
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};
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void TwccContext::onRtp(uint16_t twcc_ext_seq) {
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switch ((ExtSeqStatus) checkSeqStatus(twcc_ext_seq)) {
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case ExtSeqStatus::jumped: /*回环后，收到回环前的大ext seq包,过滤掉*/ return;
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case ExtSeqStatus::looped: /*回环，触发发送twcc rtcp*/ onSendTwcc(); break;
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case ExtSeqStatus::normal: break;
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default: /*不可达*/assert(0); break;
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}
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auto result = _rtp_recv_status.emplace(twcc_ext_seq, _ticker.createdTime());
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if (!result.second) {
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WarnL << "recv same twcc ext seq:" << twcc_ext_seq;
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return;
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}
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_max_stamp = result.first->second;
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if (!_min_stamp) {
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_min_stamp = _max_stamp;
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}
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if (checkIfNeedSendTwcc()) {
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//其他匹配条件立即发送twcc
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onSendTwcc();
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}
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}
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bool TwccContext::checkIfNeedSendTwcc() const {
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auto size = _rtp_recv_status.size();
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if (!size) {
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return false;
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}
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if (size >= kMaxSeqDelta) {
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return true;
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}
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auto delta_ms = _max_stamp - _min_stamp;
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if (delta_ms >= kMaxTimeDelta) {
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return true;
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}
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return false;
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}
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int TwccContext::checkSeqStatus(uint16_t twcc_ext_seq) const {
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if (_rtp_recv_status.empty()) {
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return (int) ExtSeqStatus::normal;
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}
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auto max = _rtp_recv_status.rbegin()->first;
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if (max > 0xFF00 && twcc_ext_seq < 0xFF) {
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//发生回环了
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TraceL << "rtp twcc ext seq looped:" << max << " -> " << twcc_ext_seq;
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return (int) ExtSeqStatus::looped;
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}
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if (twcc_ext_seq - max > 0xFFFF / 2) {
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TraceL << "rtp twcc ext seq jumped:" << max << " -> " << twcc_ext_seq;
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return (int) ExtSeqStatus::jumped;
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}
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return (int) ExtSeqStatus::normal;
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}
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void TwccContext::onSendTwcc() {
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auto max = _rtp_recv_status.rbegin()->first;
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auto begin = _rtp_recv_status.begin();
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auto min = begin->first;
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auto ref_time = begin->second;
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FCI_TWCC::TwccPacketStatus status;
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for (auto seq = min; seq <= max; ++seq) {
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int16_t delta = 0;
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SymbolStatus symbol = SymbolStatus::not_received;
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auto it = _rtp_recv_status.find(seq);
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if (it != _rtp_recv_status.end()) {
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//recv delta,单位为250us,1ms等于4x250us
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delta = (int16_t) (4 * ((int64_t) it->second - (int64_t) ref_time));
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if (delta < 0 || delta > 0xFF) {
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symbol = SymbolStatus::large_delta;
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} else {
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symbol = SymbolStatus::small_delta;
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}
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ref_time = it->second;
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}
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status.emplace(seq, std::make_pair(symbol, delta));
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}
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auto fci = FCI_TWCC::create(ref_time / 64, _twcc_pkt_count, status);
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InfoL << ((FCI_TWCC *) (fci.data()))->dumpString(fci.size());
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++_twcc_pkt_count;
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clearStatus();
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}
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void TwccContext::clearStatus() {
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_rtp_recv_status.clear();
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_min_stamp = 0;
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}
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