MPEG-2-Long GOP Mapping for MXF File Storage Applications

Abstract

The Material eXchange Format (MXF) is a comprehensive file format being widely introduced into the broadcast world. The primary MXF standard is SMPTE 377M, and this defines the file structure and metadata. To accommodate all currently used audiovisual stream formats and to provide for future developments, a generic essence container was developed (SMPTE 379M) that complied with SMPTE 377M and could be used to encapsulate many essence types. To date, many essence mappings have been written. Among them are a generic mapping of MPEG compressed data and a mapping of AES3 audio. This paper identifies the areas of MXF where constraints are applied to certain file components to encourage interoperability between various kinds of storage devices using both linear and nonlinear storage media. Constraints on two layers are considered: the use of the MXF file format structure and essence data mappings. These file constraints include the operational pattern, the use of partitions, the placement of index table segments in the file partitions, the use of index table segments, and the use of the KLV fill item.