Definition: KLV wrapped video, audio, or other data that is used/referenced by the MXF file containing them.

Description: This section looks at the linking and usage of internal essence in MXF. The header metadata within the MXF file describes the synchronization, sequencing, structure, and type of the essence stored in the file. There are a number of magic numbers that are used to link the essence to the header metadata. MXF requires that each essence container in a file is described by a top-level file-package. In addition, each essence container within a file must be stored in its own partitions. This then requires a linkage between the file package and the essence container partitions. This link is defined in the EssenceContainerData set as shown in Figure 3.7. This relates the UMID of the file package to the StreamIDs (SIDs) found in the partitions and the index tables. More details of UMIDs, SIDs material package, and source package can be found in this chapter.

Figure 3.7: Linkage between the essence container and the top-level file package

It is now necessary to connect the tracks of the file package to the individual elements of the essence container. This is done by linking the TrackNumber property of the track to the last 4 bytes of the KLV key of the element as shown in Figure 3.8. The precise rules for this linkage are defined in the MXF Generic Essence Container Specification SMPTE 379M.

Figure 3.8: Linkage between...