Video coding technology has evolved in the past years into a variety of diff erent and complex algorithms. So far the specifications of such standard algorithms have been done case by case, providing monolithic textual and reference software specifications, but lithic textual and reference software specifications, but without paying any attention to the possibility of further improvements of such monolithic standards. The MPEG Reconfigurable Video Coding (RVC) framework is a new ISO/IEC standard, currently under its final stage of development aiming at providing video codec specifications at the level of coding tools instead of monolithic descriptions. The possibility to select a subset of standard video coding algorithms to specify a decoder that satisfies application specific constraints is very attractive. However, such possibility to reconfigure codecs requires systematic procedures and tools capable of describing the new bitstream syntaxes of such new codecs. Moreover, it becomes also necessary to generate the associated parsers, capable of parsing the new bitstreams. This paper further explains the problem and describes the technologies used to describe new bitstream syntaxes. Additionally, the paper describes the methodologies and the tools for the validation of bitstream syntaxes descriptions as well as a systematic procedure for automatically synthesizing parsers from the bitstream descriptions.