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

Movie AtomsTrack AtomsNote If the edit atom or the edit list atom is missing, you can assume that the entire media is usedby the track.Figure 2-15The layout of an edit atomBytesEdit atomAtom sizeType = 'edts'44Edit list atomAtom sizeType = 'elst'VersionFlagsNumber of entriesEdit list table44134VariableEdit atoms contain the following data elements.SizeA 32-bit integer that specifies the number of bytes in this edit atom.TypeA 32-bit integer that identifies the atom type; this field must be set to 'edts'.Edit list atomSee “Edit List Atoms” (page 70).Edit List AtomsYou use the edit list atom, also shown in Figure 2-15 (page 70), to map from a time in a movie to a time in amedia, and ultimately to media data. This information is in the form of entries in an edit list table, shown inFigure 2-16 (page 71). Edit list atoms have an atom type value of 'elst'.Edit list atoms contain the following data elements.SizeA 32-bit integer that specifies the number of bytes in this edit list atom.2012-08-14 | © 2004, 2012 Apple Inc. All Rights Reserved.70