Make Windows happy.

src/frame_receiver2.h

@@ -1,6 +1,7 @@
 #ifndef TINYPLAYER2_FRAME_RECEIVER2_H
 #define TINYPLAYER2_FRAME_RECEIVER2_H
 
+#include <string>
 #include <memory>
 
 class video_decoder;

src/main.cpp

@@ -19,6 +19,14 @@
 
 #include <thread>
 
+#ifdef _MSC_VER
+
+#include <format>
+
+#define fmt std
+
+#endif
+
 // for renderer
 int monitor_index = 0;
 char *server_address;