SMPTE ST 378M (2004)

This standard defines operational pattern 1a for the exchange of a MXF file with a single item of a playable essence container comprising either a single essence element or interleaved essence elements. It defines the operating restrictions, structural metadata objects and individual attributes that shall be applied to the MXF file format specification to achieve interoperability when exchanging an MXF file as a single, continuously playable item of audio-visual material.
Operational pattern 1a is intended to meet the requirements of acquisition, storage and interchange applications that are satisfied by a single item of content packaged in a single essence container. Operational pattern 1a does not require, but does allow the use of body partitions.