The file extension MPGINDEX is used for the index files of imported MPEG video files from various Adobe media-processing products. MPGINDEX files are automatically generated files that are created when importing or adding an MPEG video file to a project.
Above all, this measure is intended to ensure faster work with the preview. In addition, such an MPEG video file must be checked only once.
Depending on the file type, the program creates various auxiliary files (cfa, pek) in the media cache. In addition, a media cache database is created on the specific Adobe programs can share. This gives the programs access to the media caches of the other programs. (if available)
In fact, MPGINDEX files are created by the Adobe Media Encoder, a software component that is part of almost all media-processing Adobe products.
You can create or clean up cache folders under 'Edit-> Preferences-> Media & Disk Cache' (Windows) or 'Settings-> Media & Disk Cache' (Mac OS). These files are only necessary during a project and can be deleted after completion.