This site allows you to easily see how modern numbers are represented as Roman numerals. Additionally, this site will show you the modern equivalent of a Roman numeral. While their use has dwindled, you may still come across Roman numerals when looking at clock-faces or at the end of T.V. shows and movies. Also, some people use Roman numerals as their name's suffix.
This number system origiated in ancient Rome (753 BC–476 AD) and consists of selected letters from the Latin alphabet.
For more information, see Roman numerals.
A codec represents something that encodes and/or decodes data. In this particular case, we are dealing with Roman and modern numerals.
For more information, see Codec.