Quicktime File Format (2012-08-14).pdf

Movie AtomsReference MoviesSizeThe number of bytes in this reference movie atom.TypeThe type of this atom; this field must be set to 'rmra'.Reference movie descriptor atomA reference movie atom must contain at least one reference movie descriptor atom, and typically containsmore than one. See “Reference Movie Descriptor Atom” (page 121) for more information.Reference Movie Descriptor AtomEach reference movie descriptor atom contains other atoms that describe where a particular movie can befound, and optionally what the system requirements are to play that movie, as well as an optional qualityrating for that movie.A reference movie descriptor atom’s parent is always a movie reference atom ('rmra'). Multiple referencemovie descriptor atoms are allowed in a given movie reference atom, and more than one is usually present.Figure 2-56 (page 121) shows the layout of this atom.Figure 2-56Reference movie descriptor atomReference Movie Descriptor atomAtom sizeType = 'rmda'Data reference atomData rate atomCPU speed atomVersion check atomComponent detect atomQuality atom'rdrf''rmdr''rmcs''rmvc''rmcd''rmqu'A reference movie descriptor atom may contain the following fields:SizeThe number of bytes in this reference movie descriptor atom.TypeThe type of this atom; this field must be set to 'rmda'.2012-08-14 | © 2004, 2012 Apple Inc. All Rights Reserved.121