Sony PSP 3000 file structure for movies, system software version 3.67
Each movie in VIDEO is matched by an almost identically-named decryption bundle in MLN_ROOT/LICENSE.
/VIDEO/UV0010-NPVA09789_CN-29192.MNVis an encrypted MP4 movie; its matching decryption bundle is
/MLN_ROOT/LICENSE/UV0010-NPVA09789_CN-29192.MNL— this happens to be an official Playstation Store download for the film Zardoz, produced and directed by John Boorman (1974).
Most information about copying DVDs to PSP elsewhere on the net is seriously out of date or misleading, and is probably not even remotely possible in the current version, at least not without carnal knowledge of the encryption codecs employed.
Decryption bundles appear to be simple XML textfiles, but their internals are arcane. They appear to contain all the information needed to decrypt an MP4 movie without "calling home" on the 'net. This is speculation, or as they say in French Kiss, "boolsheet, it is like breathing."