![]() ![]() ![]() If the handler type is not ‘mdta’, the interpretation is defined by another specification. Note: A reader parsing a metadata atom should confirm the handler type in the metadata handler atom is ‘mdta’ before interpreting any other structures in the metadata atom according to the specification presented here. The string may be empty or a single byte containing 0. The name is a NULL-terminated string in UTF-8 characters which gives a human-readable name for a metadata type, for debugging and inspection purposes. The layout of the metadata handler atom is defined: SizeĪ 32-bit unsigned integer that indicates the size in bytes of the atom structure TypeĪ 32-bit unsigned integer value set to 'hdlr' VersionĪ 32-bit integer that is set to 0 Handler typeĪ 32-bit integer that indicates the structure used in the metadata atom, set to ‘mdta’ ReservedĪn array of 3 const unsigned 32-bit integers set to 0 Name It defines the structure used for all types of metadata stored within the metadata atom. #Metamovie file formats full#The metadata handler atom is a full atom with an atom type of ‘hdlr’. Figure 3-1 Sample of a metadata atom and subatoms Metadata Handler Atom The metadata atom is the container for carrying metadata.įigure 3-1 shows a sample layout for this atom. #Metamovie file formats free#The free space atom may not occur within any other subatom contained in the metadata atom. The free space atom may be used to reserve space in a metadata atom for later additions to it, or to zero out bytes within a metadata atom after editing and removing elements from it. The country list and language list atoms can be used to store localized data in an efficient manner. Other optional atoms that may be contained in a metadata atom include the country list atom ( ‘ctry’), language list atom ( ‘lang’) and free space atom ( ‘free’). The metadata atom must contain the following subatoms: metadata handler atom ( ‘hdlr’), metadata item keys atom ( ‘keys’), and metadata item list atom ( ‘ilst’). The container for metadata is an atom of type ‘meta’. If there is user data and metadata stored in the same location, and both declare the same information, for example, declare a copyright notice, the metadata takes precedence. Only one metadata atom is allowed for each location. #Metamovie file formats movie#Within a QuickTime file, metadata can be stored within a movie atom ( ‘moov’), a track atom ( ‘trak’) or a media atom ( ‘mdia’). This identification allows for a default value (suitable for any language or country not explicitly called out), a single value, or a list of values. ![]() LocalizationĪ metadata item can be identified as specific to a country or set of countries, to a language or set of languages, or to some combination of languages and countries. Metadata is stored immediately in the corresponding atom structures, by value. It is recommended that reverse-address format be used in the general case: this provides an extensible syntax for vendor data or for other organizations or standards bodies. A key is tagged with its namespace allowing for extension in the future. These keys may be four-character codes, names in reverse-address format (such as “”) or any other key format including native formats from external metadata standards. It uses an extensible namespace allowing for meanings or keys to be added, and then referenced, from metadata items. The meaning of a metadata item identifies what it represents: a copyright notice, the performer’s name, and so on. See the Well-Known Types table for details of the standard, defined data types. The storage type of metadata items is defined via an enumerated list of data types, defined statically an example might be “plain Unicode text”. The method of storing metadata defined in this section provides an extensible and flexible design for handling a wide variety of metadata types. Note: The QuickTime file format also defines user data which, in some limited cases, can be used to store metadata. ![]()
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