Add srt caller mode and stream encryption support. (#4088)

Add srt caller mode and stream encryption support.
1. Support srt caller mode, realize srt proxy pull stream proxy push
stream;
url parameter format such as: srt://127.0.0.1:9000?streamid=#!
::r=live/test11
2. Support srt stream encrypted transmission in caller and listener
mode.

---------

Co-authored-by: xiongguangjie <xiong_panda@163.com>

src/Srt/SrtPlayer.h

@@ -0,0 +1,65 @@
+/*
+ * Copyright (c) 2016-present 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-like 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_SRTPLAYER_H
+#define ZLMEDIAKIT_SRTPLAYER_H
+
+#include "Network/Socket.h"
+#include "Player/PlayerBase.h"
+#include "Poller/Timer.h"
+#include "Util/TimeTicker.h"
+#include "srt/SrtTransport.hpp"
+#include "Http/HttpRequester.h"
+#include <memory>
+#include <string>
+#include "SrtCaller.h"
+
+namespace mediakit {
+
+
+// 实现了srt代理拉流功能
+class SrtPlayer
+    : public PlayerBase , public SrtCaller {
+public:
+    using Ptr = std::shared_ptr<SrtPlayer>;
+
+    SrtPlayer(const toolkit::EventPoller::Ptr &poller);
+    ~SrtPlayer() override;
+
+    //// PlayerBase override////
+    void play(const std::string &strUrl) override;
+    void teardown() override;
+    void pause(bool pause) override;
+    void speed(float speed) override;
+
+protected:
+
+    //// SrtCaller override////
+    void onHandShakeFinished() override;
+	void onSRTData(SRT::DataPacket::Ptr pkt) override;
+    void onResult(const toolkit::SockException &ex) override;
+
+    bool isPlayer() override {return true;}
+
+    uint16_t getLatency() override;
+    float getTimeOutSec() override;
+    std::string getPassphrase() override;
+
+protected:
+	//是否为性能测试模式
+	bool _benchmark_mode = false;
+
+    //超时功能实现
+    toolkit::Ticker _recv_ticker;
+    std::shared_ptr<toolkit::Timer> _check_timer;
+};
+
+} /* namespace mediakit */
+#endif /* ZLMEDIAKIT_SRTPLAYER_H */