ISO/IEC 23002-4:2014 defines the description of the MPEG video tool library (VTL) based on the decoder description specified in ISO/IEC 23001-4. This tool library defines the specification of FUs, which are sufficient to build complete decoding solutions according to the following coding standards:ISO/IEC 14496-2 (MPEG-4 Simple Profile), andISO/IEC 14496-10 (MPEG-4 AVC Constrained Baseline Profile).The objective of ISO/IEC 23001-4 is to define the general framework principles, and ISO/IEC 23002-4:2014 defines the MPEG VTL that includes relevant tools (or FUs) from the existing MPEG coding standards. Each FU is defined in the form of a textual description. The conventions followed by the input and output behavior are also described.Implementations compliant with ISO/IEC 23002-4:2014 can be designed using any software or hardware language and components. The reference software for the textual specification of FUs is written in RVC-CAL language of which a formal syntax is provided in ISO/IEC 23001-4, and which will be defined in Amendment 1 to ISO/IEC 23002-4.