优化rtmp时间戳修正

src/MediaFile/Stamp.h

@@ -33,16 +33,17 @@ using namespace toolkit;
 
 namespace mediakit {
 
+//该类解决时间戳回环、回退问题
+//计算相对时间戳或者产生平滑时间戳
 class Stamp {
 public:
-    Stamp(bool modifyStamp = false) {_modifyStamp = modifyStamp;};
+    Stamp() = default;
     ~Stamp() = default;
     void revise(uint32_t dts, uint32_t pts, int64_t &dts_out, int64_t &pts_out);
 private:
     int64_t _start_dts = 0;
     int64_t _dts_inc = 0;
     bool _first = true;
-    bool _modifyStamp;
     std::shared_ptr<SmoothTicker> _ticker;
 };