Wireshark-dev: [Wireshark-dev] how to convert to file encode from utf-8 to ASCII?

From: "??????????" <237825552@xxxxxx>
Date: Thu, 27 Mar 2014 15:22:16 +0800
In the readme.developer,it say that the developer should convert the source file encode into ASCII,but when i extract the compress file ,it's default file encode is utf-8,what should i do ?