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

Movie AtomsMedia AtomsData reference atomSee “Data Reference Atoms” (page 94).Data Reference AtomsData reference atoms contain tabular data that instructs the data handler component how to access the media’sdata. Figure 2-31 (page 93) shows the data reference atom.The data reference atom contains the following data elements.SizeA 32-bit integer that specifies the number of bytes in this data reference atom.TypeA 32-bit integer that identifies the atom type; this field must be set to 'dref'.VersionA 1-byte specification of the version of this data reference atom.FlagsA 3-byte space for data reference flags. Set this field to 0.Number of entriesA 32-bit integer containing the count of data references that follow.Data referencesAn array of data references.Each data reference is formatted like an atom and contains the following data elements.SizeA 32-bit integer that specifies the number of bytes in the data reference.TypeA 32-bit integer that specifies the type of the data in the data reference. Table 2-4 (page 95) lists validtype values.VersionA 1-byte specification of the version of the data reference.2012-08-14 | © 2004, 2012 Apple Inc. All Rights Reserved.94