This class represents the movie action. This is definitively detailed in:.

The ISO PDF Specification, ISO 32000-1:2008 PDF 1.7; Table: 209, page 425.

The ISO PDF Specification, ISO 32000-2:2017 PDF 2.0; Table: 213, page 517.

System.Object
    WebSupergoo.ABCpdf14.Elements.Element
       WebSupergoo.ABCpdf14.Elements.ActionElement
          WebSupergoo.ABCpdf14.Elements.MovieActionElement

A movie action controls playback of a movie annotation. The Operation entry selects the command: Play, Stop, Pause, or Resume. The Annotation entry identifies the target by indirect reference; T identifies it by title string.