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.