feat(video2x): improved the timer

Signed-off-by: k4yt3x <i@k4yt3x.com>

include/libvideo2x/timer.h

@@ -0,0 +1,34 @@
+#ifndef TIMER_H
+#define TIMER_H
+
+#include <atomic>
+#include <chrono>
+#include <cstdint>
+#include <thread>
+
+class Timer {
+   public:
+    Timer();
+    ~Timer();
+
+    void start();
+    void pause();
+    void resume();
+    void stop();
+
+    bool is_running() const;
+    bool is_paused() const;
+    int64_t get_elapsed_time() const;
+
+   private:
+    std::atomic<bool> running;
+    std::atomic<bool> paused;
+    std::thread timer_thread;
+    int64_t elapsed_time;
+    std::chrono::steady_clock::time_point start_time;
+    std::chrono::steady_clock::time_point pause_start_time;
+
+    void update_elapsed_time();
+};
+
+#endif  // TIMER_H