Skip to main content

Matroska Tags
draft-ietf-cellar-tags-02

The information below is for an old version of the document.
Document Type
This is an older version of an Internet-Draft whose latest revision state is "Active".
Authors Steve Lhomme, Moritz Bunkus, Dave Rice
Last updated 2019-07-30 (Latest revision 2019-07-22)
RFC stream Internet Engineering Task Force (IETF)
Formats
Additional resources Mailing list discussion
Stream WG state WG Document
Document shepherd (None)
IESG IESG state I-D Exists
Consensus boilerplate Unknown
Telechat date (None)
Responsible AD (None)
Send notices to (None)
draft-ietf-cellar-tags-02
cellar                                                         S. Lhomme
Internet-Draft
Intended status: Standards Track                               M. Bunkus
Expires: January 23, 2020
                                                                 D. Rice
                                                           July 22, 2019

                             Matroska Tags
                       draft-ietf-cellar-tags-02

Abstract

   This document defines the Matroska tags, namely the tag names and
   their respective semantic meaning.

Status of This Memo

   This Internet-Draft is submitted in full conformance with the
   provisions of BCP 78 and BCP 79.

   Internet-Drafts are working documents of the Internet Engineering
   Task Force (IETF).  Note that other groups may also distribute
   working documents as Internet-Drafts.  The list of current Internet-
   Drafts is at https://datatracker.ietf.org/drafts/current/.

   Internet-Drafts are draft documents valid for a maximum of six months
   and may be updated, replaced, or obsoleted by other documents at any
   time.  It is inappropriate to use Internet-Drafts as reference
   material or to cite them other than as "work in progress."

   This Internet-Draft will expire on January 23, 2020.

Copyright Notice

   Copyright (c) 2019 IETF Trust and the persons identified as the
   document authors.  All rights reserved.

   This document is subject to BCP 78 and the IETF Trust's Legal
   Provisions Relating to IETF Documents
   (https://trustee.ietf.org/license-info) in effect on the date of
   publication of this document.  Please review these documents
   carefully, as they describe your rights and restrictions with respect
   to this document.  Code Components extracted from this document must
   include Simplified BSD License text as described in Section 4.e of
   the Trust Legal Provisions and are provided without warranty as
   described in the Simplified BSD License.

Lhomme, et al.          Expires January 23, 2020                [Page 1]
Internet-Draft                  Matroska                       July 2019

Table of Contents

   1.  Introduction  . . . . . . . . . . . . . . . . . . . . . . . .   2
   2.  Status of this document . . . . . . . . . . . . . . . . . . .   3
   3.  Security Considerations . . . . . . . . . . . . . . . . . . .   3
   4.  IANA Considerations . . . . . . . . . . . . . . . . . . . . .   3
   5.  Notations and Conventions . . . . . . . . . . . . . . . . . .   3
   6.  Tagging . . . . . . . . . . . . . . . . . . . . . . . . . . .   3
     6.1.  Why official tags matter  . . . . . . . . . . . . . . . .   4
     6.2.  Tag translations  . . . . . . . . . . . . . . . . . . . .   4
     6.3.  Tag Formatting  . . . . . . . . . . . . . . . . . . . . .   4
     6.4.  Target types  . . . . . . . . . . . . . . . . . . . . . .   5
     6.5.  Official tags . . . . . . . . . . . . . . . . . . . . . .   7
     6.6.  Nesting Information . . . . . . . . . . . . . . . . . . .   7
     6.7.  Organization Information  . . . . . . . . . . . . . . . .   7
     6.8.  Titles  . . . . . . . . . . . . . . . . . . . . . . . . .   8
     6.9.  Nested Information  . . . . . . . . . . . . . . . . . . .   8
     6.10. Entities  . . . . . . . . . . . . . . . . . . . . . . . .   9
     6.11. Search and Classification . . . . . . . . . . . . . . . .  11
     6.12. Temporal Information  . . . . . . . . . . . . . . . . . .  13
     6.13. Spacial Information . . . . . . . . . . . . . . . . . . .  13
     6.14. Personal  . . . . . . . . . . . . . . . . . . . . . . . .  14
     6.15. Technical Information . . . . . . . . . . . . . . . . . .  15
     6.16. Identifiers . . . . . . . . . . . . . . . . . . . . . . .  17
     6.17. Commercial  . . . . . . . . . . . . . . . . . . . . . . .  17
     6.18. Legal . . . . . . . . . . . . . . . . . . . . . . . . . .  18
     6.19. Notes . . . . . . . . . . . . . . . . . . . . . . . . . .  18
     7.1.  URIs  . . . . . . . . . . . . . . . . . . . . . . . . . .  19
   Authors' Addresses  . . . . . . . . . . . . . . . . . . . . . . .  20

1.  Introduction

   Matroska aims to become THE standard of multimedia container formats.
   It can store timestamped multimedia data but also chapters and tags.
   The "Tag Elements" add important metadata to identify and classify
   the information found in a "Matroska Segment".  It can tag a whole
   "Segment", separate "Track Elements", individual "Chapter Elements"
   or "Attachment Elements".

   While the Matroska tagging framework allows anyone to create their
   own custom tags, it's important to have a common set of values for
   interoperability.  This document intends to define a set of common
   tag names used in Matroska.

Lhomme, et al.          Expires January 23, 2020                [Page 2]
Internet-Draft                  Matroska                       July 2019

2.  Status of this document

   This document is a work-in-progress specification defining the
   Matroska file format as part of the IETF Cellar working group [1].
   It uses basic elements and concepts already defined in the Matroska
   specifications defined by this workgroup.

3.  Security Considerations

   "Tag" values can be either strings or binary blobs.  This document
   inherits security considerations from the EBML and Matroska
   documents.

4.  IANA Considerations

   To be determined.

5.  Notations and Conventions

   The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT",
   "SHOULD", "SHOULD NOT", "RECOMMENDED", "MAY", and "OPTIONAL" in this
   document are to be interpreted as described in RFC 2119 [2].

6.  Tagging

   When a Tag is nested within another Tag, the nested Tag becomes an
   attribute of the base tag.  For instance, if you wanted to store the
   dates that a singer used certain addresses for, that singer being the
   lead singer for a track that included multiple bands simultaneously,
   then your tag tree would look something like this:

   o  Targets

      *  TrackUID

   o  BAND

      *  LEADPERFORMER

      *  ADDRESS

         +  DATE

         +  DATEEND

      *  ADDRESS

         +  DATE

Lhomme, et al.          Expires January 23, 2020                [Page 3]
Internet-Draft                  Matroska                       July 2019

   In this way, it becomes possible to store any Tag as attributes of
   another tag.

   Multiple items SHOULD never be stored as a list in a single
   TagString.  If there is more than one tag of a certain type to be
   stored, then more than one SimpleTag SHOULD be used.

   For authoring Tags outside of EBML, the following XML syntax is
   proposed [3] used in mkvmerge [4].  Binary data SHOULD be stored
   using BASE64 encoding if it is being stored at authoring time.

6.1.  Why official tags matter

   There is a debate between people who think all tags SHOULD be free
   and those who think all tags SHOULD be strict.  If you look at this
   page you will realize we are in between.

   Advanced-users application might let you put any tag in your file.
   But for the rest of the applications, they usually give you a basic
   list of tags you can use.  Both have their needs.  But it's usually a
   bad idea to use custom/exotic tags because you will probably be the
   only person to use this information even though everyone else could
   benefit from it.  So hopefully when someone wants to put information
   in one's file, they will find an official one that fit them and
   hopefully use it ! If it's not in the list, this person can contact
   us any time for addition of such a missing tag.  But it doesn't mean
   it will be accepted... Matroska files are not meant the become a
   whole database of people who made costumes for a film.  A website
   would be better for that... It's hard to define what SHOULD be in and
   what doesn't make sense in a file.  So we'll treat each request
   carefully.

   We also need an official list simply for developers to be able to
   display relevant information in their own design (if they choose to
   support a list of meta-information they SHOULD know which tag has the
   wanted meaning so that other apps could understand the same meaning).

6.2.  Tag translations

   To be able to save tags from other systems to Matroska we need to
   translate them to our system.  There is a translation table on our
   site [5].

6.3.  Tag Formatting

   o  The TagName SHOULD always be written in all capital letters and
      contain no space.

Lhomme, et al.          Expires January 23, 2020                [Page 4]
Internet-Draft                  Matroska                       July 2019

   o  The fields with dates SHOULD have the following format: YYYY-MM-DD
      hh:mm:ss.mss YYYY = Year, MM = Month, DD = Days, HH = Hours, mm =
      Minutes, ss = Seconds, mss = Milliseconds.  To store less
      accuracy, you remove items starting from the right.  To store only
      the year, you would use, "2004".  To store a specific day such as
      May 1st, 2003, you would use "2003-05-01".

   o  Fields that require a Float SHOULD use the "." mark instead of the
      "," mark.  To display it differently for another local,
      applications SHOULD support auto replacement on display.  Also, a
      thousandths separator SHOULD NOT be used.

   o  For currency amounts, there SHOULD only be a numeric value in the
      Tag. Only numbers, no letters or symbols other than ".".  For
      instance, you would store "15.59" instead of "$15.59USD".

6.4.  Target types

   The TargetType element allows tagging of different parts that are
   inside or outside a given file.  For example in an audio file with
   one song you could have information about the album it comes from and
   even the CD set even if it's not found in the file.

   For application to know what kind of information (like TITLE) relates
   to a certain level (CD title or track title), we also need a set of
   official TargetType names.  For now audio and video will have
   different values & names.  That also means the same tag name can have
   different meanings depending on where it is (otherwise we would end
   up with 15 TITLE_ tags).

Lhomme, et al.          Expires January 23, 2020                [Page 5]
Internet-Draft                  Matroska                       July 2019

   +-----------------+------------+------------+-----------------------+
   | TargetTypeValue | Audio      | Video      | Comment               |
   |                 | strings    | strings    |                       |
   +-----------------+------------+------------+-----------------------+
   |        70       | COLLECTION | COLLECTION | the high hierarchy    |
   |                 |            |            | consisting of many    |
   |                 |            |            | different lower items |
   |        60       | EDITION /  | SEASON /   | a list of lower       |
   |                 | ISSUE /    | SEQUEL /   | levels grouped        |
   |                 | VOLUME /   | VOLUME     | together              |
   |                 | OPUS       |            |                       |
   |        50       | ALBUM /    | MOVIE /    | the most common       |
   |                 | OPERA /    | EPISODE /  | grouping level of     |
   |                 | CONCERT    | CONCERT    | music and video       |
   |                 |            |            | (equals to an episode |
   |                 |            |            | for TV series)        |
   |        40       | PART /     | PART /     | when an album or      |
   |                 | SESSION    | SESSION    | episode has different |
   |                 |            |            | logical parts         |
   |        30       | TRACK /    | CHAPTER    | the common parts of   |
   |                 | SONG       |            | an album or a movie   |
   |        20       | SUBTRACK / | SCENE      | corresponds to parts  |
   |                 | PART /     |            | of a track for audio  |
   |                 | MOVEMENT   |            | (like a movement)     |
   |        10       | -          | SHOT       | the lowest hierarchy  |
   |                 |            |            | found in music or     |
   |                 |            |            | movies                |
   +-----------------+------------+------------+-----------------------+

   An upper level value tag applies to the lower level.  That means if a
   CD has the same artist for all tracks, you just need to set the
   ARTIST tag at level 50 (ALBUM) and not to each TRACK (but you can).
   That also means that if some parts of the CD have no known ARTIST the
   value MUST be set to nothing (a void string "").

   When a level doesn't exist it MUST NOT be specified in the files, so
   that the TOTAL_PARTS and PART_NUMBER elements match the same levels.

   Here is an example of how these "organizational" tags work: If you
   set 10 TOTAL_PARTS to the ALBUM level (40) it means the album
   contains 10 lower parts.  The lower part in question is the first
   lower level that is specified in the file.  So if it's TRACK (30)
   then that means it contains 10 tracks.  If it's MOVEMENT (20) that
   means it's 10 movements, etc.

Lhomme, et al.          Expires January 23, 2020                [Page 6]
Internet-Draft                  Matroska                       July 2019

6.5.  Official tags

   The following is a complete list of the supported Matroska Tags.
   While it is possible to use Tag names that are not listed below, this
   is not recommended as compatibility will be compromised.  If you find
   that there is a Tag missing that you would like to use, then please
   contact the Matroska team for its inclusion in the specifications
   before the format reaches 1.0.

6.6.  Nesting Information

   Nesting Information tags are intended to contain other tags.

   +----------+-------+------------------------------------------------+
   | Tag Name | Type  | Description                                    |
   +----------+-------+------------------------------------------------+
   | ORIGINAL | -     | A special tag that is meant to have other tags |
   |          |       | inside (using nested tags) to describe the     |
   |          |       | original work of art that this item is based   |
   |          |       | on. All tags in this list can be used "under"  |
   |          |       | the ORIGINAL tag like LYRICIST, PERFORMER,     |
   |          |       | etc.                                           |
   | SAMPLE   | -     | A tag that contains other tags to describe a   |
   |          |       | sample used in the targeted item taken from    |
   |          |       | another work of art. All tags in this list can |
   |          |       | be used "under" the SAMPLE tag like TITLE,     |
   |          |       | ARTIST, DATE_RELEASED, etc.                    |
   | COUNTRY  | UTF-8 | The name of the country (biblio ISO-639-2 [6]) |
   |          |       | that is meant to have other tags inside (using |
   |          |       | nested tags) to country specific information   |
   |          |       | about the item. All tags in this list can be   |
   |          |       | used "under" the COUNTRY_SPECIFIC tag like     |
   |          |       | LABEL, PUBLISH_RATING, etc.                    |
   +----------+-------+------------------------------------------------+

6.7.  Organization Information

Lhomme, et al.          Expires January 23, 2020                [Page 7]
Internet-Draft                  Matroska                       July 2019

   +-------------+-------+---------------------------------------------+
   | Tag Name    | Type  | Description                                 |
   +-------------+-------+---------------------------------------------+
   | TOTAL_PARTS | UTF-8 | Total number of parts defined at the first  |
   |             |       | lower level. (e.g. if TargetType is ALBUM,  |
   |             |       | the total number of tracks of an audio CD)  |
   | PART_NUMBER | UTF-8 | Number of the current part of the current   |
   |             |       | level. (e.g. if TargetType is TRACK, the    |
   |             |       | track number of an audio CD)                |
   | PART_OFFSET | UTF-8 | A number to add to PART_NUMBER when the     |
   |             |       | parts at that level don't start at 1. (e.g. |
   |             |       | if TargetType is TRACK, the track number of |
   |             |       | the second audio CD)                        |
   +-------------+-------+---------------------------------------------+

6.8.  Titles

   +----------+-------+------------------------------------------------+
   | Tag Name | Type  | Description                                    |
   +----------+-------+------------------------------------------------+
   | TITLE    | UTF-8 | The title of this item. For example, for music |
   |          |       | you might label this "Canon in D", or for      |
   |          |       | video's audio track you might use "English     |
   |          |       | 5.1" This is akin to the TIT2 tag in ID3.      |
   | SUBTITLE | UTF-8 | Sub Title of the entity.                       |
   +----------+-------+------------------------------------------------+

6.9.  Nested Information

   Nested Information includes tags contained in other tags.

Lhomme, et al.          Expires January 23, 2020                [Page 8]
Internet-Draft                  Matroska                       July 2019

   +-------------+-------+---------------------------------------------+
   | Tag Name    | Type  | Description                                 |
   +-------------+-------+---------------------------------------------+
   | URL         | UTF-8 | URL corresponding to the tag it's included  |
   |             |       | in.                                         |
   | SORT_WITH   | UTF-8 | A child element to indicate what            |
   |             |       | alternative value the parent tag can have   |
   |             |       | to be sorted, for example "Pet Shop Boys"   |
   |             |       | instead of "The Pet Shop Boys". Or "Marley  |
   |             |       | Bob" and "Marley Ziggy" (no comma needed).  |
   | INSTRUMENTS | UTF-8 | The instruments that are being used/played, |
   |             |       | separated by a comma. It SHOULD be a child  |
   |             |       | of the following tags: ARTIST,              |
   |             |       | LEAD_PERFORMER or ACCOMPANIMENT.            |
   | EMAIL       | UTF-8 | Email corresponding to the tag it's         |
   |             |       | included in.                                |
   | ADDRESS     | UTF-8 | The physical address of the entity. The     |
   |             |       | address SHOULD include a country code. It   |
   |             |       | can be useful for a recording label.        |
   | FAX         | UTF-8 | The fax number corresponding to the tag     |
   |             |       | it's included in. It can be useful for a    |
   |             |       | recording label.                            |
   | PHONE       | UTF-8 | The phone number corresponding to the tag   |
   |             |       | it's included in. It can be useful for a    |
   |             |       | recording label.                            |
   +-------------+-------+---------------------------------------------+

6.10.  Entities

   +----------------------+-------+------------------------------------+
   | Tag Name             | Type  | Description                        |
   +----------------------+-------+------------------------------------+
   | ARTIST               | UTF-8 | A person or band/collective        |
   |                      |       | generally considered responsible   |
   |                      |       | for the work. This is akin to the  |
   |                      |       | TPE1 tag in ID3 [7].               |
   | LEAD_PERFORMER       | UTF-8 | Lead Performer/Soloist(s). This    |
   |                      |       | can sometimes be the same as       |
   |                      |       | ARTIST.                            |
   | ACCOMPANIMENT        | UTF-8 | Band/orchestra/accompaniment/music |
   |                      |       | ian. This is akin to the TPE2 tag  |
   |                      |       | in ID3 [8].                        |
   | COMPOSER             | UTF-8 | The name of the composer of this   |
   |                      |       | item. This is akin to the TCOM tag |
   |                      |       | in ID3 [9].                        |
   | ARRANGER             | UTF-8 | The person who arranged the piece, |
   |                      |       | e.g., Ravel.                       |
   | LYRICS               | UTF-8 | The lyrics corresponding to a song |

Lhomme, et al.          Expires January 23, 2020                [Page 9]
Internet-Draft                  Matroska                       July 2019

   |                      |       | (in case audio synchronization is  |
   |                      |       | not known or as a doublon to a     |
   |                      |       | subtitle track). Editing this      |
   |                      |       | value when subtitles are found     |
   |                      |       | SHOULD also result in editing the  |
   |                      |       | subtitle track for more            |
   |                      |       | consistency.                       |
   | LYRICIST             | UTF-8 | The person who wrote the lyrics    |
   |                      |       | for a musical item. This is akin   |
   |                      |       | to the TEXT [10] tag in ID3.       |
   | CONDUCTOR            | UTF-8 | Conductor/performer refinement.    |
   |                      |       | This is akin to the TPE3 [11].     |
   | DIRECTOR             | UTF-8 | This is akin to the IART tag in    |
   |                      |       | RIFF [12].                         |
   | ASSISTANT_DIRECTOR   | UTF-8 | The name of the assistant          |
   |                      |       | director.                          |
   | DIRECTOR_OF_PHOTOGRA | UTF-8 | The name of the director of        |
   | PHY                  |       | photography, also known as         |
   |                      |       | cinematographer. This is akin to   |
   |                      |       | the ICNM tag in Extended RIFF.     |
   | SOUND_ENGINEER       | UTF-8 | The name of the sound engineer or  |
   |                      |       | sound recordist.                   |
   | ART_DIRECTOR         | UTF-8 | The person who oversees the        |
   |                      |       | artists and craftspeople who build |
   |                      |       | the sets.                          |
   | PRODUCTION_DESIGNER  | UTF-8 | Artist responsible for designing   |
   |                      |       | the overall visual appearance of a |
   |                      |       | movie.                             |
   | CHOREGRAPHER         | UTF-8 | The name of the choregrapher       |
   | COSTUME_DESIGNER     | UTF-8 | The name of the costume designer   |
   | ACTOR                | UTF-8 | An actor or actress playing a role |
   |                      |       | in this movie. This is the         |
   |                      |       | person's real name, not the        |
   |                      |       | character's name the person is     |
   |                      |       | playing.                           |
   | CHARACTER            | UTF-8 | The name of the character an actor |
   |                      |       | or actress plays in this movie.    |
   |                      |       | This SHOULD be a sub-tag of an     |
   |                      |       | "ACTOR" tag in order not to cause  |
   |                      |       | ambiguities.                       |
   | WRITTEN_BY           | UTF-8 | The author of the story or script  |
   |                      |       | (used for movies and TV shows).    |
   | SCREENPLAY_BY        | UTF-8 | The author of the screenplay or    |
   |                      |       | scenario (used for movies and TV   |
   |                      |       | shows).                            |
   | EDITED_BY            | UTF-8 | This is akin to the IEDT tag in    |
   |                      |       | Extended RIFF.                     |
   | PRODUCER             | UTF-8 | Produced by. This is akin to the   |

Lhomme, et al.          Expires January 23, 2020               [Page 10]
Internet-Draft                  Matroska                       July 2019

   |                      |       | IPRO tag in Extended RIFF.         |
   | COPRODUCER           | UTF-8 | The name of a co-producer.         |
   | EXECUTIVE_PRODUCER   | UTF-8 | The name of an executive producer. |
   | DISTRIBUTED_BY       | UTF-8 | This is akin to the IDST tag in    |
   |                      |       | Extended RIFF.                     |
   | MASTERED_BY          | UTF-8 | The engineer who mastered the      |
   |                      |       | content for a physical medium or   |
   |                      |       | for digital distribution.          |
   | ENCODED_BY           | UTF-8 | This is akin to the TENC tag [13]  |
   |                      |       | in ID3.                            |
   | MIXED_BY             | UTF-8 | DJ mix by the artist specified     |
   | REMIXED_BY           | UTF-8 | Interpreted, remixed, or otherwise |
   |                      |       | modified by. This is akin to the   |
   |                      |       | TPE4 tag in ID3 [14].              |
   | PRODUCTION_STUDIO    | UTF-8 | This is akin to the ISTD tag in    |
   |                      |       | Extended RIFF.                     |
   | THANKS_TO            | UTF-8 | A very general tag for everyone    |
   |                      |       | else that wants to be listed.      |
   | PUBLISHER            | UTF-8 | This is akin to the TPUB tag in    |
   |                      |       | ID3 [15].                          |
   | LABEL                | UTF-8 | The record label or imprint on the |
   |                      |       | disc.                              |
   +----------------------+-------+------------------------------------+

6.11.  Search and Classification

Lhomme, et al.          Expires January 23, 2020               [Page 11]
Internet-Draft                  Matroska                       July 2019

   +---------------------+--------+------------------------------------+
   | Tag Name            | Type   | Description                        |
   +---------------------+--------+------------------------------------+
   | GENRE               | UTF-8  | The main genre (classical,         |
   |                     |        | ambient-house, synthpop, sci-fi,   |
   |                     |        | drama, etc). The format follows    |
   |                     |        | the infamous TCON tag in ID3.      |
   | MOOD                | UTF-8  | Intended to reflect the mood of    |
   |                     |        | the item with a few keywords, e.g. |
   |                     |        | "Romantic", "Sad" or "Uplifting".  |
   |                     |        | The format follows that of the     |
   |                     |        | TMOO tag in ID3.                   |
   | ORIGINAL_MEDIA_TYPE | UTF-8  | Describes the original type of the |
   |                     |        | media, such as, "DVD", "CD",       |
   |                     |        | "computer image," "drawing,"       |
   |                     |        | "lithograph," and so forth. This   |
   |                     |        | is akin to the TMED tag in ID3     |
   |                     |        | [16].                              |
   | CONTENT_TYPE        | UTF-8  | The type of the item. e.g.         |
   |                     |        | Documentary, Feature Film,         |
   |                     |        | Cartoon, Music Video, Music, Sound |
   |                     |        | FX, ...                            |
   | SUBJECT             | UTF-8  | Describes the topic of the file,   |
   |                     |        | such as "Aerial view of Seattle."  |
   | DESCRIPTION         | UTF-8  | A short description of the         |
   |                     |        | content, such as "Two birds        |
   |                     |        | flying."                           |
   | KEYWORDS            | UTF-8  | Keywords to the item separated by  |
   |                     |        | a comma, used for searching.       |
   | SUMMARY             | UTF-8  | A plot outline or a summary of the |
   |                     |        | story.                             |
   | SYNOPSIS            | UTF-8  | A description of the story line of |
   |                     |        | the item.                          |
   | INITIAL_KEY         | UTF-8  | The initial key that a musical     |
   |                     |        | track starts in. The format is     |
   |                     |        | identical to ID3.                  |
   | PERIOD              | UTF-8  | Describes the period that the      |
   |                     |        | piece is from or about. For        |
   |                     |        | example, "Renaissance".            |
   | LAW_RATING          | UTF-8  | Depending on the "COUNTRY" it's    |
   |                     |        | the format of the rating of a      |
   |                     |        | movie (P, R, X in the USA, an age  |
   |                     |        | in other countries or a URI        |
   |                     |        | defining a logo).                  |
   | ICRA                | binary | The ICRA [17] content rating for   |
   |                     |        | parental control. (Previously      |
   |                     |        | RSACi)                             |
   +---------------------+--------+------------------------------------+

Lhomme, et al.          Expires January 23, 2020               [Page 12]
Internet-Draft                  Matroska                       July 2019

6.12.  Temporal Information

   +----------------+-------+------------------------------------------+
   | Tag Name       | Type  | Description                              |
   +----------------+-------+------------------------------------------+
   | DATE_RELEASED  | UTF-8 | The time that the item was originally    |
   |                |       | released. This is akin to the TDRL tag   |
   |                |       | in ID3.                                  |
   | DATE_RECORDED  | UTF-8 | The time that the recording began. This  |
   |                |       | is akin to the TDRC tag in ID3.          |
   | DATE_ENCODED   | UTF-8 | The time that the encoding of this item  |
   |                |       | was completed began. This is akin to the |
   |                |       | TDEN tag in ID3.                         |
   | DATE_TAGGED    | UTF-8 | The time that the tags were done for     |
   |                |       | this item. This is akin to the TDTG tag  |
   |                |       | in ID3.                                  |
   | DATE_DIGITIZED | UTF-8 | The time that the item was transferred   |
   |                |       | to a digital medium. This is akin to the |
   |                |       | IDIT tag in RIFF.                        |
   | DATE_WRITTEN   | UTF-8 | The time that the writing of the         |
   |                |       | music/script began.                      |
   | DATE_PURCHASED | UTF-8 | Information on when the file was         |
   |                |       | purchased (see also Section 6.17).       |
   +----------------+-------+------------------------------------------+

6.13.  Spacial Information

   +----------------------+-------+------------------------------------+
   | Tag Name             | Type  | Description                        |
   +----------------------+-------+------------------------------------+
   | RECORDING_LOCATION   | UTF-8 | The location where the item was    |
   |                      |       | recorded. The countries            |
   |                      |       | corresponding to the string, same  |
   |                      |       | 2 octets as in Internet domains    |
   |                      |       | [18], or possibly ISO-3166 [19].   |
   |                      |       | This code is followed by a comma,  |
   |                      |       | then more detailed information     |
   |                      |       | such as state/province, another    |
   |                      |       | comma, and then city. For example, |
   |                      |       | "US, Texas, Austin". This will     |
   |                      |       | allow for easy sorting. It is okay |
   |                      |       | to only store the country, or the  |
   |                      |       | country and the state/province.    |
   |                      |       | More detailed information can be   |
   |                      |       | added after the city through the   |
   |                      |       | use of additional commas. In cases |
   |                      |       | where the province/state is        |
   |                      |       | unknown, but you want to store the |

Lhomme, et al.          Expires January 23, 2020               [Page 13]
Internet-Draft                  Matroska                       July 2019

   |                      |       | city, simply leave a space between |
   |                      |       | the two commas. For example, "US,  |
   |                      |       | , Austin".                         |
   | COMPOSITION_LOCATION | UTF-8 | Location that the item was         |
   |                      |       | originally designed/written. The   |
   |                      |       | countries corresponding to the     |
   |                      |       | string, same 2 octets as in        |
   |                      |       | Internet domains [20], or possibly |
   |                      |       | ISO-3166 [21]. This code is        |
   |                      |       | followed by a comma, then more     |
   |                      |       | detailed information such as       |
   |                      |       | state/province, another comma, and |
   |                      |       | then city. For example, "US,       |
   |                      |       | Texas, Austin". This will allow    |
   |                      |       | for easy sorting. It is okay to    |
   |                      |       | only store the country, or the     |
   |                      |       | country and the state/province.    |
   |                      |       | More detailed information can be   |
   |                      |       | added after the city through the   |
   |                      |       | use of additional commas. In cases |
   |                      |       | where the province/state is        |
   |                      |       | unknown, but you want to store the |
   |                      |       | city, simply leave a space between |
   |                      |       | the two commas. For example, "US,  |
   |                      |       | , Austin".                         |
   | COMPOSER_NATIONALITY | UTF-8 | Nationality of the main composer   |
   |                      |       | of the item, mostly for classical  |
   |                      |       | music. The countries corresponding |
   |                      |       | to the string, same 2 octets as in |
   |                      |       | Internet domains [22], or possibly |
   |                      |       | ISO-3166 [23].                     |
   +----------------------+-------+------------------------------------+

6.14.  Personal

Lhomme, et al.          Expires January 23, 2020               [Page 14]
Internet-Draft                  Matroska                       July 2019

   +--------------+-------+--------------------------------------------+
   | Tag Name     | Type  | Description                                |
   +--------------+-------+--------------------------------------------+
   | COMMENT      | UTF-8 | Any comment related to the content.        |
   | PLAY_COUNTER | UTF-8 | The number of time the item has been       |
   |              |       | played.                                    |
   | RATING       | UTF-8 | A numeric value defining how much a person |
   |              |       | likes the song/movie. The number is        |
   |              |       | between 0 and 5 with decimal values        |
   |              |       | possible (e.g. 2.7), 5(.0) being the       |
   |              |       | highest possible rating. Other rating      |
   |              |       | systems with different ranges will have to |
   |              |       | be scaled.                                 |
   +--------------+-------+--------------------------------------------+

6.15.  Technical Information

Lhomme, et al.          Expires January 23, 2020               [Page 15]
Internet-Draft                  Matroska                       July 2019

   +------------------+--------+---------------------------------------+
   | Tag Name         | Type   | Description                           |
   +------------------+--------+---------------------------------------+
   | ENCODER          | UTF-8  | The software or hardware used to      |
   |                  |        | encode this item. ("LAME" or "XviD")  |
   | ENCODER_SETTINGS | UTF-8  | A list of the settings used for       |
   |                  |        | encoding this item. No specific       |
   |                  |        | format.                               |
   | BPS              | UTF-8  | The average bits per second of the    |
   |                  |        | specified item. This is only the data |
   |                  |        | in the Blocks, and excludes headers   |
   |                  |        | and any container overhead.           |
   | FPS              | UTF-8  | The average frames per second of the  |
   |                  |        | specified item. This is typically the |
   |                  |        | average number of Blocks per second.  |
   |                  |        | In the event that lacing is used,     |
   |                  |        | each laced chunk is to be counted as  |
   |                  |        | a separate frame.                     |
   | BPM              | UTF-8  | Average number of beats per minute in |
   |                  |        | the complete target (e.g. a chapter). |
   |                  |        | Usually a decimal number.             |
   | MEASURE          | UTF-8  | In music, a measure is a unit of time |
   |                  |        | in Western music like "4/4". It       |
   |                  |        | represents a regular grouping of      |
   |                  |        | beats, a meter, as indicated in       |
   |                  |        | musical notation by the time          |
   |                  |        | signature.. The majority of the       |
   |                  |        | contemporary rock and pop music you   |
   |                  |        | hear on the radio these days is       |
   |                  |        | written in the 4/4 time signature.    |
   | TUNING           | UTF-8  | It is saved as a frequency in hertz   |
   |                  |        | to allow near-perfect tuning of       |
   |                  |        | instruments to the same tone as the   |
   |                  |        | musical piece (e.g. "441.34" in       |
   |                  |        | Hertz). The default value is 440.0    |
   |                  |        | Hz.                                   |
   | REPLAYGAIN_GAIN  | binary | The gain to apply to reach 89dB SPL   |
   |                  |        | on playback. This is based on the     |
   |                  |        | Replay Gain standard [24]. Note that  |
   |                  |        | ReplayGain information can be found   |
   |                  |        | at all TargetType levels (track,      |
   |                  |        | album, etc).                          |
   | REPLAYGAIN_PEAK  | binary | The maximum absolute peak value of    |
   |                  |        | the item. This is based on the Replay |
   |                  |        | Gain standard [25].                   |
   +------------------+--------+---------------------------------------+

Lhomme, et al.          Expires January 23, 2020               [Page 16]
Internet-Draft                  Matroska                       July 2019

6.16.  Identifiers

   +----------------+--------+-----------------------------------------+
   | Tag Name       | Type   | Description                             |
   +----------------+--------+-----------------------------------------+
   | ISRC           | UTF-8  | The International Standard Recording    |
   |                |        | Code [26], excluding the "ISRC" prefix  |
   |                |        | and including hyphens.                  |
   | MCDI           | binary | This is a binary dump of the TOC of the |
   |                |        | CDROM that this item was taken from.    |
   |                |        | This holds the same information as the  |
   |                |        | MCDI in ID3.                            |
   | ISBN           | UTF-8  | International Standard Book Number [27] |
   | BARCODE        | UTF-8  | EAN-13 [28] (European Article           |
   |                |        | Numbering) or UPC-A [29] (Universal     |
   |                |        | Product Code) bar code identifier       |
   | CATALOG_NUMBER | UTF-8  | A label-specific string used to         |
   |                |        | identify the release (TIC 01 for        |
   |                |        | example).                               |
   | LABEL_CODE     | UTF-8  | A 4-digit or 5-digit number to identify |
   |                |        | the record label, typically printed as  |
   |                |        | (LC) xxxx or (LC) 0xxxx on CDs medias   |
   |                |        | or covers (only the number is stored).  |
   | LCCN           | UTF-8  | Library of Congress Control Number [30] |
   | IMDB           | UTF-8  | Internet Movie Database (IMDb) [31]     |
   |                |        | identifier. 'tt' followed by at least 7 |
   |                |        | digits for Movies, TV Shows and         |
   |                |        | Episodes.                               |
   | TMDB           | UTF-8  | The Movie Database (TMDb) [32]          |
   |                |        | identifier. The variable length digits  |
   |                |        | string MUST be prefixed with either     |
   |                |        | "movie/" or "tv/".                      |
   | TVDB           | UTF-8  | The TV Database (TheTVDB) [33]          |
   |                |        | identifier. Variable length all-digits  |
   |                |        | string identifying a TV Show.           |
   +----------------+--------+-----------------------------------------+

6.17.  Commercial

Lhomme, et al.          Expires January 23, 2020               [Page 17]
Internet-Draft                  Matroska                       July 2019

   +-------------------+-------+---------------------------------------+
   | Tag Name          | Type  | Description                           |
   +-------------------+-------+---------------------------------------+
   | PURCHASE_ITEM     | UTF-8 | URL to purchase this file. This is    |
   |                   |       | akin to the WPAY tag in ID3.          |
   | PURCHASE_INFO     | UTF-8 | Information on where to purchase this |
   |                   |       | album. This is akin to the WCOM tag   |
   |                   |       | in ID3.                               |
   | PURCHASE_OWNER    | UTF-8 | Information on the person who         |
   |                   |       | purchased the file. This is akin to   |
   |                   |       | the TOWN tag in ID3 [34].             |
   | PURCHASE_PRICE    | UTF-8 | The amount paid for entity. There     |
   |                   |       | SHOULD only be a numeric value in     |
   |                   |       | here. Only numbers, no letters or     |
   |                   |       | symbols other than ".". For instance, |
   |                   |       | you would store "15.59" instead of    |
   |                   |       | "$15.59USD".                          |
   | PURCHASE_CURRENCY | UTF-8 | The currency type used to pay for the |
   |                   |       | entity. Use ISO-4217 [35] for the 3   |
   |                   |       | letter currency code.                 |
   +-------------------+-------+---------------------------------------+

6.18.  Legal

   +----------------------+-------+------------------------------------+
   | Tag Name             | Type  | Description                        |
   +----------------------+-------+------------------------------------+
   | COPYRIGHT            | UTF-8 | The copyright information as per   |
   |                      |       | the copyright holder. This is akin |
   |                      |       | to the TCOP tag in ID3.            |
   | PRODUCTION_COPYRIGHT | UTF-8 | The copyright information as per   |
   |                      |       | the production copyright holder.   |
   |                      |       | This is akin to the TPRO tag in    |
   |                      |       | ID3.                               |
   | LICENSE              | UTF-8 | The license applied to the content |
   |                      |       | (like Creative Commons variants).  |
   | TERMS_OF_USE         | UTF-8 | The terms of use for this item.    |
   |                      |       | This is akin to the USER tag in    |
   |                      |       | ID3.                               |
   +----------------------+-------+------------------------------------+

6.19.  Notes

   o  In the Target list, a logical OR is applied on all tracks, a
      logical OR is applied on all chapters.  Then a logical AND is
      applied between the Tracks list and the Chapters list to know if
      an element belongs to this Target.

Lhomme, et al.          Expires January 23, 2020               [Page 18]
Internet-Draft                  Matroska                       July 2019

7.  References

7.1.  URIs

   [1] https://datatracker.ietf.org/wg/cellar/charter/

   [2] https://tools.ietf.org/html/rfc2119

   [3] http://www.matroska.org/files/tags/matroskatags.dtd

   [4] http://www.bunkus.org/videotools/mkvtoolnix/doc/
       mkvmerge.html#mkvmerge.tags

   [5] othertagsystems/comparetable.html

   [6] https://www.loc.gov/standards/iso639-2/php/English_list.php

   [7] http://id3.org/id3v2.3.0#TPE1

   [8] http://id3.org/id3v2.3.0#TPE2

   [9] http://id3.org/id3v2.3.0#TCOM

   [10] http://id3.org/id3v2.3.0#TEXT

   [11] http://id3.org/id3v2.3.0#TPE3

   [12] https://sno.phy.queensu.ca/~phil/exiftool/TagNames/RIFF.html

   [13] http://id3.org/id3v2.3.0#TENC

   [14] http://id3.org/id3v2.3.0#TPE4

   [15] http://id3.org/id3v2.3.0#TPUB

   [16] http://id3.org/id3v2.3.0#TMED

   [17] http://www.icra.org/

   [18] https://www.iana.org/whois

   [19] https://www.iso.org/iso-3166-country-codes.html

   [20] https://www.iana.org/whois

   [21] https://www.iso.org/iso-3166-country-codes.html

   [22] https://www.iana.org/whois

Lhomme, et al.          Expires January 23, 2020               [Page 19]
Internet-Draft                  Matroska                       July 2019

   [23] https://www.iso.org/iso-3166-country-codes.html

   [24] http://www.replaygain.org/

   [25] http://www.replaygain.org/

   [26] http://www.ifpi.org/isrc/isrc_handbook.html#Heading198

   [27] https://www.isbn-international.org/

   [28] https://www.gs1.org/standards/barcodes/ean-upc

   [29] http://www.uc-council.org/

   [30] https://www.loc.gov/marc/lccn.html

   [31] https://www.imdb.com/

   [32] https://www.themoviedb.org/

   [33] https://www.thetvdb.com/

   [34] http://id3.org/id3v2.3.0#TOWN

   [35] https://www.xe.com/iso4217.php

Authors' Addresses

   Steve Lhomme

   Email: slhomme@matroska.org

   Moritz Bunkus

   Email: moritz@bunkus.org

   Dave Rice

   Email: dave@dericed.com

Lhomme, et al.          Expires January 23, 2020               [Page 20]