First commit of brand new rewrite

io/media.cpp

@@ -0,0 +1,9 @@
+#include "media.h"
+
+extern "C" {
+	#include <libavformat/avformat.h>
+}
+
+long Media::get_length_in_frames(float frame_rate) {
+	return ceil((float) length / (float) AV_TIME_BASE * frame_rate);
+}