整理nack相关代码

webrtc/Nack.cpp

+/*
+ * 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 > UINT32_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);
+    }
+}
\ No newline at end of file

webrtc/Nack.h

+/*
+ * 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.
+ */
+
+#ifndef ZLMEDIAKIT_NACK_H
+#define ZLMEDIAKIT_NACK_H
+
+#include "Rtsp/Rtsp.h"
+#include "Rtcp/RtcpFCI.h"
+
+using namespace mediakit;
+
+class NackList {
+public:
+    NackList() = default;
+    ~NackList() = default;
+
+    void push_back(RtpPacket::Ptr rtp);
+    void for_each_nack(const FCI_NACK &nack, const function<void(const RtpPacket::Ptr &rtp)> &cb);
+
+private:
+    void pop_front();
+    uint32_t get_cache_ms();
+    RtpPacket::Ptr *get_rtp(uint16_t seq);
+
+private:
+    deque<uint16_t> _nack_cache_seq;
+    unordered_map<uint16_t, RtpPacket::Ptr> _nack_cache_pkt;
+};
+
+class NackContext {
+public:
+    using onNack = function<void(const FCI_NACK &nack)>;
+
+    NackContext() = default;
+    ~NackContext() = default;
+
+    void received(uint16_t seq);
+    void setOnNack(onNack cb);
+
+private:
+    void eraseFrontSeq();
+    void doNack(const FCI_NACK &nack);
+
+private:
+    onNack _cb;
+    set<uint16_t> _seq;
+    uint16_t _last_max_seq = 0;
+};
+
+#endif //ZLMEDIAKIT_NACK_H

webrtc/WebRtcTransport.h

@@ -22,6 +22,8 @@
 #include "Rtsp/RtspMediaSourceImp.h"
 #include "Rtcp/RtcpContext.h"
 #include "Rtcp/RtcpFCI.h"
+#include "Nack.h"
+
 using namespace toolkit;
 using namespace mediakit;
 
@@ -126,152 +128,6 @@ private:
 };
 
 class RtpChannel;
-
-class NackList {
-public:
-    void 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();
-        }
-    }
-
-    template<typename FUNC>
-    void for_each_nack(const FCI_NACK &nack, const FUNC &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;
-        }
-    }
-
-private:
-    void pop_front() {
-        if (_nack_cache_seq.empty()) {
-            return;
-        }
-        _nack_cache_pkt.erase(_nack_cache_seq.front());
-        _nack_cache_seq.pop_front();
-    }
-
-    RtpPacket::Ptr *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 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);
-    }
-
-private:
-    static constexpr uint32_t kMaxNackMS = 10 * 1000;
-    deque<uint16_t> _nack_cache_seq;
-    unordered_map<uint16_t, RtpPacket::Ptr > _nack_cache_pkt;
-};
-
-class NackContext {
-public:
-    using onNack = function<void(const FCI_NACK &nack)>;
-
-    void 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 > UINT32_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 setOnNack(onNack cb) {
-        _cb = std::move(cb);
-    }
-
-private:
-    void doNack(const FCI_NACK &nack) {
-        if (_cb) {
-            _cb(nack);
-        }
-    }
-
-    void 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);
-        }
-    }
-
-private:
-    onNack _cb;
-    set<uint16_t> _seq;
-    uint16_t _last_max_seq = 0;
-};
-
 class MediaTrack {
 public:
     using Ptr = std::shared_ptr<MediaTrack>;