Enable ffmpeg building with MinGW-w64. The libraries were compiled with gcc 4.7, however is has been claimed there are issues with gcc > 4.4 so this is for testing purposes. Still it doesn't crash on startup anymore. Forgot to mention on ffmpeg lib commit that committed ffmpeg version is 0.10.2

source/creator/CMakeLists.txt

@@ -584,7 +584,14 @@ elseif(WIN32)
 				${LIBDIR}/ffmpeg/lib/swscale-2.dll
 			DESTINATION ${TARGETDIR}
 		)
-
+		if(WITH_MINGW64)
+		install(
+			FILES
+				${LIBDIR}/ffmpeg/lib/swresample-0.dll
+				${LIBDIR}/ffmpeg/lib/xvidcore.dll
+			DESTINATION ${TARGETDIR}
+		)
+		endif()
 	endif()
 
 	if(WITH_CODEC_SNDFILE)