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struct AVFormatContext;
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* Public Metadata API.
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* @defgroup metadata_api Public Metadata API
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* The metadata API allows libavformat to export metadata tags to a client
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* application using a sequence of key/value pairs. Like all strings in Libav,
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* metadata must be stored as UTF-8 encoded Unicode. Note that metadata
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* exported by demuxers isn't checked to be valid UTF-8 in most cases.
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* Important concepts to keep in mind:
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* 1. Keys are unique; there can never be 2 tags with the same key. This is
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* - Keys are unique; there can never be 2 tags with the same key. This is
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* also meant semantically, i.e., a demuxer should not knowingly produce
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* several keys that are literally different but semantically identical.
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* E.g., key=Author5, key=Author6. In this example, all authors must be
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* placed in the same tag.
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* 2. Metadata is flat, not hierarchical; there are no subtags. If you
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* - Metadata is flat, not hierarchical; there are no subtags. If you
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* want to store, e.g., the email address of the child of producer Alice
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* and actor Bob, that could have key=alice_and_bobs_childs_email_address.
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* 3. Several modifiers can be applied to the tag name. This is done by
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* - Several modifiers can be applied to the tag name. This is done by
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* appending a dash character ('-') and the modifier name in the order
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* they appear in the list below -- e.g. foo-eng-sort, not foo-sort-eng.
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* a) language -- a tag whose value is localized for a particular language
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* - language -- a tag whose value is localized for a particular language
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* is appended with the ISO 639-2/B 3-letter language code.
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* For example: Author-ger=Michael, Author-eng=Mike
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* The original/default language is in the unqualified "Author" tag.
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* A demuxer should set a default if it sets any translated tag.
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* b) sorting -- a modified version of a tag that should be used for
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* - sorting -- a modified version of a tag that should be used for
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* sorting will have '-sort' appended. E.g. artist="The Beatles",
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* artist-sort="Beatles, The".
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* 4. Demuxers attempt to export metadata in a generic format, however tags
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* - Demuxers attempt to export metadata in a generic format, however tags
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* with no generic equivalents are left as they are stored in the container.
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* Follows a list of generic tag names:
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* album -- name of the set this work belongs to
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* album_artist -- main creator of the set/album, if different from artist.
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* e.g. "Various Artists" for compilation albums.
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* artist -- main creator of the work
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* comment -- any additional description of the file.
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* composer -- who composed the work, if different from artist.
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* copyright -- name of copyright holder.
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* creation_time-- date when the file was created, preferably in ISO 8601.
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* date -- date when the work was created, preferably in ISO 8601.
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* disc -- number of a subset, e.g. disc in a multi-disc collection.
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* encoder -- name/settings of the software/hardware that produced the file.
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* encoded_by -- person/group who created the file.
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* filename -- original name of the file.
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* genre -- <self-evident>.
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* language -- main language in which the work is performed, preferably
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* in ISO 639-2 format. Multiple languages can be specified by
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* separating them with commas.
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* performer -- artist who performed the work, if different from artist.
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* E.g for "Also sprach Zarathustra", artist would be "Richard
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* Strauss" and performer "London Philharmonic Orchestra".
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* publisher -- name of the label/publisher.
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* service_name -- name of the service in broadcasting (channel name).
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* service_provider -- name of the service provider in broadcasting.
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* title -- name of the work.
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* track -- number of this work in the set, can be in form current/total.
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* variant_bitrate -- the total bitrate of the bitrate variant that the current stream is part of
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album -- name of the set this work belongs to
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album_artist -- main creator of the set/album, if different from artist.
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e.g. "Various Artists" for compilation albums.
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artist -- main creator of the work
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comment -- any additional description of the file.
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composer -- who composed the work, if different from artist.
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copyright -- name of copyright holder.
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creation_time-- date when the file was created, preferably in ISO 8601.
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date -- date when the work was created, preferably in ISO 8601.
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disc -- number of a subset, e.g. disc in a multi-disc collection.
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encoder -- name/settings of the software/hardware that produced the file.
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encoded_by -- person/group who created the file.
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filename -- original name of the file.
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genre -- <self-evident>.
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language -- main language in which the work is performed, preferably
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in ISO 639-2 format. Multiple languages can be specified by
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separating them with commas.
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performer -- artist who performed the work, if different from artist.
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E.g for "Also sprach Zarathustra", artist would be "Richard
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Strauss" and performer "London Philharmonic Orchestra".
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publisher -- name of the label/publisher.
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service_name -- name of the service in broadcasting (channel name).
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service_provider -- name of the service provider in broadcasting.
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title -- name of the work.
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track -- number of this work in the set, can be in form current/total.
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variant_bitrate -- the total bitrate of the bitrate variant that the current stream is part of
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* Look in the examples section for an application example how to use the Metadata API.
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#if FF_API_OLD_METADATA2
added
removed
libavformat/avformat.h
