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Common Catalog Format for moq-transport
draft-wilaw-moq-catalogformat-02

Document Type Active Internet-Draft (individual)
Authors Suhas Nandakumar , Will Law , Mo Zanaty
Last updated 2023-11-30
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draft-wilaw-moq-catalogformat-02
Media Over QUIC                                            S. Nandakumar
Internet-Draft                                                     Cisco
Intended status: Informational                                    W. Law
Expires: 2 June 2024                                              Akamai
                                                               M. Zanaty
                                                                   Cisco
                                                        30 November 2023

                Common Catalog Format for moq-transport
                    draft-wilaw-moq-catalogformat-02

Abstract

   This specification defines a Common Catalog specification for
   streaming formats implementing the MOQ Transport Protocol
   [MoQTransport].  Media over QUIC Transport (MOQT) defines a publish/
   subscribe based unified media delivery protocol for delivering media
   for streaming and interactive applications over QUIC.  The catalog
   describes the content made available by a publisher, including
   information necessary for subscribers to select, subscribe and
   initialize tracks.

About This Document

   This note is to be removed before publishing as an RFC.

   The latest revision of this draft can be found at
   https://wilaw.github.io/catalog-format/draft-wilaw-moq-
   catalogformat.html.  Status information for this document may be
   found at https://datatracker.ietf.org/doc/draft-wilaw-moq-
   catalogformat/.

   Discussion of this document takes place on the Media Over QUIC
   Working Group mailing list (mailto:moq@ietf.org), which is archived
   at https://mailarchive.ietf.org/arch/browse/moq/.  Subscribe at
   https://www.ietf.org/mailman/listinfo/moq/.

   Source for this draft and an issue tracker can be found at
   https://github.com/wilaw/catalog-format.

Status of This Memo

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

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   Copyright (c) 2023 IETF Trust and the persons identified as the
   document authors.  All rights reserved.

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   Please review these documents carefully, as they describe your rights
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Table of Contents

   1.  Introduction  . . . . . . . . . . . . . . . . . . . . . . . .   4
   2.  Conventions and Definitions . . . . . . . . . . . . . . . . .   4
   3.  Catalog . . . . . . . . . . . . . . . . . . . . . . . . . . .   4
     3.1.  Catalog version . . . . . . . . . . . . . . . . . . . . .   4
     3.2.  Catalog Fields  . . . . . . . . . . . . . . . . . . . . .   5
       3.2.1.  Streaming format  . . . . . . . . . . . . . . . . . .   7
       3.2.2.  Streaming format version  . . . . . . . . . . . . . .   8
       3.2.3.  Tracks  . . . . . . . . . . . . . . . . . . . . . . .   8
       3.2.4.  Catalogs  . . . . . . . . . . . . . . . . . . . . . .   8
       3.2.5.  Catalog object  . . . . . . . . . . . . . . . . . . .   8
       3.2.6.  Tracks object . . . . . . . . . . . . . . . . . . . .   8
       3.2.7.  Track namespace . . . . . . . . . . . . . . . . . . .   8
       3.2.8.  Track name  . . . . . . . . . . . . . . . . . . . . .   8
       3.2.9.  Packaging . . . . . . . . . . . . . . . . . . . . . .   8
       3.2.10. Track operations  . . . . . . . . . . . . . . . . . .   9
       3.2.11. Track label . . . . . . . . . . . . . . . . . . . . .  10
       3.2.12. Render group  . . . . . . . . . . . . . . . . . . . .  10
       3.2.13. Alternate group . . . . . . . . . . . . . . . . . . .  10
       3.2.14. Initialization data . . . . . . . . . . . . . . . . .  10
       3.2.15. Initialization track  . . . . . . . . . . . . . . . .  10

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       3.2.16. Selection parameters  . . . . . . . . . . . . . . . .  10
       3.2.17. Dependencies  . . . . . . . . . . . . . . . . . . . .  11
       3.2.18. Temporal ID . . . . . . . . . . . . . . . . . . . . .  11
       3.2.19. Spatial ID  . . . . . . . . . . . . . . . . . . . . .  11
       3.2.20. Codec . . . . . . . . . . . . . . . . . . . . . . . .  11
       3.2.21. Mimetype  . . . . . . . . . . . . . . . . . . . . . .  11
       3.2.22. Framerate . . . . . . . . . . . . . . . . . . . . . .  11
       3.2.23. Bitrate . . . . . . . . . . . . . . . . . . . . . . .  11
       3.2.24. Width . . . . . . . . . . . . . . . . . . . . . . . .  11
       3.2.25. Height  . . . . . . . . . . . . . . . . . . . . . . .  12
       3.2.26. Audio sample rate . . . . . . . . . . . . . . . . . .  12
       3.2.27. Channel configuration . . . . . . . . . . . . . . . .  12
       3.2.28. Display width . . . . . . . . . . . . . . . . . . . .  12
       3.2.29. Display height  . . . . . . . . . . . . . . . . . . .  12
       3.2.30. Language  . . . . . . . . . . . . . . . . . . . . . .  12
     3.3.  Catalog Patch . . . . . . . . . . . . . . . . . . . . . .  12
     3.4.  Catalog Examples  . . . . . . . . . . . . . . . . . . . .  13
       3.4.1.  Time-aligned Audio/Video Tracks with single
               quality . . . . . . . . . . . . . . . . . . . . . . .  13
       3.4.2.  Simulcast video tracks - 3 alternate qualities along
               with audio  . . . . . . . . . . . . . . . . . . . . .  14
       3.4.3.  SVC video tracks with 2 spatial and 2 temporal
               qualities . . . . . . . . . . . . . . . . . . . . . .  15
       3.4.4.  Patch update adding a track . . . . . . . . . . . . .  17
       3.4.5.  Patch update removing a track . . . . . . . . . . . .  18
       3.4.6.  Patch update removing all tracks and terminating the
               broadcast . . . . . . . . . . . . . . . . . . . . . .  18
       3.4.7.  CMAF Tracks with multiple qualities of audio and
               video . . . . . . . . . . . . . . . . . . . . . . . .  18
       3.4.8.  Mixed format example - CMAF and LOC packaging in the
               same catalog  . . . . . . . . . . . . . . . . . . . .  19
       3.4.9.  CMAF Tracks with inband init segments . . . . . . . .  20
       3.4.10. Time-aligned Audio/Video Tracks with custom field
               values  . . . . . . . . . . . . . . . . . . . . . . .  21
       3.4.11. A catalog referencing catalogs for two different
               formats . . . . . . . . . . . . . . . . . . . . . . .  22
   4.  Security Considerations . . . . . . . . . . . . . . . . . . .  23
   5.  IANA Considerations . . . . . . . . . . . . . . . . . . . . .  23
     5.1.  MoQ Streaming Format Type Registry  . . . . . . . . . . .  23
   Acknowledgments . . . . . . . . . . . . . . . . . . . . . . . . .  23
   Normative References  . . . . . . . . . . . . . . . . . . . . . .  23
   Authors' Addresses  . . . . . . . . . . . . . . . . . . . . . . .  24

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1.  Introduction

   MOQT [MoQTransport] defines a transport protocol that utilizes the
   QUIC network protocol [QUIC] and WebTransport[WebTrans] to move
   objects between publishers, subscribers and intermediaries.  Tracks
   are identified using a tuple of the Track Namespace and the Track
   Name.  A MOQT Catalog is a specialized track which captures details
   of all the tracks output by a publisher, including the identities,
   media profiles, initialization data and inter-track relationships.
   The mapping of media characteristics of objects with the tracks, as
   well as relative prioritization of those objects, are captured in
   separate MoQ Streaming Format specifications.  This specification
   defines a JSON encoded catalog.

2.  Conventions and Definitions

   The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT",
   "SHOULD", "SHOULD NOT", "RECOMMENDED", "NOT RECOMMENDED", "MAY", and
   "OPTIONAL" in this document are to be interpreted as described in RFC
   2119 [RFC2119].

3.  Catalog

   A Catalog is a MOQT Object that provides information about tracks
   from a given publisher.  A Catalog is used by publishers for
   advertising their output and for subscribers in consuming that
   output.  The payload of the Catalog object is opaque to Relays and
   can be end-to-end encrypted.  The Catalog provides the names and
   namespaces of the tracks being produced, along with the relationship
   between tracks, properties of the tracks that consumers may use for
   selection and any relevant initialization data.

   A special case of the catalog exists which describes other catalogs
   instead of tracks.  A catalog might describe tracks, or catalogs, but
   never both at the same time.

3.1.  Catalog version

   Versions of this catalog specification are defined using
   monotonically increasing integers.  There is no guarantee that future
   catalog versions are backwards compatible and field definitions and
   interpretation may change between versions.  A subscriber MUST NOT
   attempt to parse a catalog version which it does not understand.

   This document defines version 1.

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3.2.  Catalog Fields

   A catalog is a JSON [JSON] document, comprised of a series of
   mandatory and optional fields.  At a minimum, a catalog MUST provide
   all mandatory fields and one of either a 'tracks' field or a
   'catalogs' field.  A producer MAY add additional fields to the ones
   described in this draft.  Custom field names MUST NOT collide with
   field names described in this draft.  To prevent custom field name
   collisions with future versions, custom field names SHOULD be
   prefixed using reverse domain name notation e.g "com.example-size".
   The order of field names within the JSON document is not important.
   Any track or catalog field declared at the root level is inherited by
   all tracks or catalogs.  Any track or catalog field declared within a
   track or catalog object overwrites any inherited value.

   A parser MUST ignore fields it does not understand.

   Table 1 provides an overview of all fields defined by this document.

   +==============+======================+========+========+======+==========+
   |Field         |Name                  |Required|Location|JSON  |Definition|
   |              |                      |        |        |type  |          |
   +==============+======================+========+========+======+==========+
   |Catalog       |version               |yes     |R       |String|Section   |
   |version       |                      |        |        |      |3.1       |
   +--------------+----------------------+--------+--------+------+----------+
   |Streaming     |streamingFormat       |yes     |RC      |String|Section   |
   |format        |                      |        |        |      |3.2.1     |
   +--------------+----------------------+--------+--------+------+----------+
   |Streaming     |streamingFormatVersion|yes     |RC      |String|Section   |
   |format version|                      |        |        |      |3.2.2     |
   +--------------+----------------------+--------+--------+------+----------+
   |Tracks        |tracks                |opt     |R       |Array |Section   |
   |              |                      |        |        |      |3.2.3     |
   +--------------+----------------------+--------+--------+------+----------+
   |Catalogs      |catalogs              |opt     |R       |Array |Section   |
   |              |                      |        |        |      |3.2.4     |
   +--------------+----------------------+--------+--------+------+----------+
   |Track         |namespace             |opt     |RTC     |String|Section   |
   |namespace     |                      |        |        |      |3.2.7     |
   +--------------+----------------------+--------+--------+------+----------+
   |Track name    |name                  |yes     |TC      |String|Section   |
   |              |                      |        |        |      |3.2.8     |
   +--------------+----------------------+--------+--------+------+----------+
   |Packaging     |packaging             |yes     |RT      |String|Section   |
   |              |                      |        |        |      |3.2.9     |
   +--------------+----------------------+--------+--------+------+----------+
   |Track         |operation             |yes     |RT      |String|Section   |

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   |operation     |                      |        |        |      |3.2.10    |
   +--------------+----------------------+--------+--------+------+----------+
   |Track label   |label                 |opt     |RT      |String|Section   |
   |              |                      |        |        |      |3.2.11    |
   +--------------+----------------------+--------+--------+------+----------+
   |Render group  |renderGroup           |opt     |RT      |Number|Section   |
   |              |                      |        |        |      |3.2.12    |
   +--------------+----------------------+--------+--------+------+----------+
   |Alternate     |altGroup              |opt     |RT      |Number|Section   |
   |group         |                      |        |        |      |3.2.13    |
   +--------------+----------------------+--------+--------+------+----------+
   |Initialization|initData              |opt     |RT      |String|Section   |
   |data          |                      |        |        |      |3.2.14    |
   +--------------+----------------------+--------+--------+------+----------+
   |Initialization|initTrack             |opt     |RT      |String|Section   |
   |track         |                      |        |        |      |3.2.15    |
   +--------------+----------------------+--------+--------+------+----------+
   |Selection     |selectionParams       |opt     |RT      |Object|Section   |
   |parameters    |                      |        |        |      |3.2.16    |
   +--------------+----------------------+--------+--------+------+----------+
   |Dependencies  |depends               |opt     |T       |Array |Section   |
   |              |                      |        |        |      |3.2.17    |
   +--------------+----------------------+--------+--------+------+----------+
   |Temporal ID   |temporalId            |opt     |T       |Number|Section   |
   |              |                      |        |        |      |3.2.18    |
   +--------------+----------------------+--------+--------+------+----------+
   |Spatial ID    |spatialId             |opt     |T       |Number|Section   |
   |              |                      |        |        |      |3.2.19    |
   +--------------+----------------------+--------+--------+------+----------+
   |Codec         |codec                 |opt     |S       |String|Section   |
   |              |                      |        |        |      |3.2.20    |
   +--------------+----------------------+--------+--------+------+----------+
   |Mime type     |mimeType              |opt     |S       |String|Section   |
   |              |                      |        |        |      |3.2.21    |
   +--------------+----------------------+--------+--------+------+----------+
   |Framerate     |framerate             |opt     |S       |Number|Section   |
   |              |                      |        |        |      |3.2.22    |
   +--------------+----------------------+--------+--------+------+----------+
   |Bitrate       |bitrate               |opt     |S       |Number|Section   |
   |              |                      |        |        |      |3.2.23    |
   +--------------+----------------------+--------+--------+------+----------+
   |Width         |width                 |opt     |S       |Number|Section   |
   |              |                      |        |        |      |3.2.24    |
   +--------------+----------------------+--------+--------+------+----------+
   |Height        |height                |opt     |S       |Number|Section   |
   |              |                      |        |        |      |3.2.25    |
   +--------------+----------------------+--------+--------+------+----------+
   |Audio sample  |samplerate            |opt     |S       |Number|Section   |

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   |rate          |                      |        |        |      |3.2.26    |
   +--------------+----------------------+--------+--------+------+----------+
   |Channel       |channelConfig         |opt     |S       |String|Section   |
   |configuration |                      |        |        |      |3.2.27    |
   +--------------+----------------------+--------+--------+------+----------+
   |Display width |displayWidth          |opt     |S       |Number|Section   |
   |              |                      |        |        |      |3.2.28    |
   +--------------+----------------------+--------+--------+------+----------+
   |Display height|displayHeight         |opt     |S       |Number|Section   |
   |              |                      |        |        |      |3.2.29    |
   +--------------+----------------------+--------+--------+------+----------+
   |Language      |lang                  |opt     |S       |String|Section   |
   |              |                      |        |        |      |3.2.30    |
   +--------------+----------------------+--------+--------+------+----------+

                                  Table 1

   Required: 'yes' indicates a mandatory field in non-patch catalogs,
   'opt' indicates an optional field

   Location:

   *  'R' - the field is located in the Root of the JSON object.

   *  'RC' - the field may be located in either the Root or a Catalog
      object.

   *  'RTC' - the field may be located in either the Root, or a Track
      object or a Catalog object.

   *  'TC' - the field may be located in either a Track object or a
      Catalog object.

   *  'RT' - the field may be located in either the Root or a Track
      object.

   *  'T' - the field is located in a Track object.

   *  'S' - the field is located in the Selection Parameters object.

3.2.1.  Streaming format

   A number indicating the streaming format type.  Every MoQ Streaming
   Format normatively referencing this catalog format MUST register
   itself in the "MoQ Streaming Format Type" table.  See Section 5 for
   additional details.

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3.2.2.  Streaming format version

   A string indicating the version of the streaming format to which this
   catalog applies.  The structure of the version string is defined by
   the streaming format.

3.2.3.  Tracks

   An array of track objects Section 3.2.6.  If the 'tracks' field is
   present then the 'catalog' field MUST NOT be present.

3.2.4.  Catalogs

   An array of catalog objects Section 3.2.5.  If the 'catalogs' field
   is present then the 'tracks' field MUST NOT be present.  A catalog
   MUST NOT list itself in the catalog array.

3.2.5.  Catalog object

   A catalog object is a collection of fields whose location is
   specified as 'RC', 'TC' or 'RTC' in Table 1.

3.2.6.  Tracks object

   A track object is a collection of fields whose location is specified
   as 'RT', 'TC' or 'RTC' in Table 1.

3.2.7.  Track namespace

   The name space under which the track name is defined.  See section
   2.3 of [MoQTransport].  If the track namespace is declared in the
   root of the JSON document, then its value is inherited by all tracks
   and catalogs and it does not need to be re-declared within each track
   or catalog object.  A namespace declared in a track object or catalog
   object overwrites any inherited name space.  The track namespace is
   optional.  If it is not declared at the root or track level, then
   each track MUST inherit the namespace of the catalog track.

3.2.8.  Track name

   A string defining the name of the track.  See section 2.3 of
   [MoQTransport].  Within the catalog, track names MUST be unique per
   namespace.

3.2.9.  Packaging

   A string defining the type of payload encapsulation.  Allowed values
   are strings as defined in Table 2.

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   Table 2: Allowed packaging values

                     +======+========+==============+
                     | Name | Value  | Draft        |
                     +======+========+==============+
                     | CMAF | "cmaf" | See RFC XXXX |
                     +------+--------+--------------+
                     | LOC  | "loc"  | See RFC XXXX |
                     +------+--------+--------------+

                                 Table 2

3.2.10.  Track operations

   Each track description can specify an optional operation value that
   identifies the catalog producer's intent.  Track operation is an
   enumeration of values as defined below.

   *  Add: Indicates the track is added to the catalog and the consumers
      of the catalog may subscribe to the track.

   *  Delete: Indicates that media producer is no longer producing media
      on the associated track.  Subscribers SHOULD terminate their
      subscriptions.

   A catalog update in which all previously added tracks are deleted
   SHOULD be interpreted by a subscriber to indicate that the publisher
   has terminated the broadcast.

   Table 3 defines the numerical values for the track operations.

   Table 3: Allowed track operations

                    +========+========+===============+
                    | Name   | Value  | Default value |
                    +========+========+===============+
                    | Add    | add    | yes           |
                    +--------+--------+---------------+
                    | Delete | delete |               |
                    +--------+--------+---------------+

                                  Table 3

   The default track operation is 'add'.  This value does not need to be
   declared in the track object.

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3.2.11.  Track label

   A string defining a human-readable label for the track.  Examples
   might be "Overhead camera view" or "Deutscher Kommentar".  Note that
   the [JSON] spec requires UTF-8 support by decoders.

3.2.12.  Render group

   An integer specifying a group of tracks which are designed to be
   rendered together.  Tracks with the same group number SHOULD be
   rendered simultaneously, are usually time-aligned and are designed to
   accompany one another.  A common example would be tying together
   audio and video tracks.

3.2.13.  Alternate group

   An integer specifying a group of tracks which are alternate versions
   of one-another.  Alternate tracks represent the same media content,
   but differ in their selection properties.  Alternate tracks SHOULD
   have matching framerate Section 3.2.22 and media time sequences.  A
   subscriber typically subscribes to one track from a set of tracks
   specifying the same alternate group number.  A common example would
   be a set video tracks of the same content offered in alternate
   bitrates.

3.2.14.  Initialization data

   A string holding Base64 [BASE64] encoded initialization data for the
   track.

3.2.15.  Initialization track

   A string specifying the track name of another track which holds
   initialization data for the current track.  Initialization tracks
   MUST NOT be added to the tracks array Section 3.2.3.  They are
   referenced only via the initialization track field of the track which
   they initialize.

3.2.16.  Selection parameters

   An object holding a series of name/value pairs which a subscriber can
   use to select tracks for subscription.  If present, the selection
   parameters object MUST NOT be empty.  Any selection parameters
   declared at the root level are inherited by all tracks.  A selection
   parameters object may exist at both the root and track level.  Any
   declaration of a selection parameter at the track level overrides the
   inherited root value.

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3.2.17.  Dependencies

   Certain tracks may depend on other tracks for decoding.  Dependencies
   holds an array of track names Section 3.2.8 on which the current
   track is dependent.  Since only the track name is signaled, the
   namespace of the dependencies is assumed to match that of the track
   declaring the dependencies.

3.2.18.  Temporal ID

   A number identifying the temporal layer/sub-layer encoding of the
   track, starting with 0 for the base layer, and increasing with higher
   temporal fidelity.

3.2.19.  Spatial ID

   A number identifying the spatial layer encoding of the track,
   starting with 0 for the base layer, and increasing with higher
   fidelity.

3.2.20.  Codec

   A string defining the codec used to encode the track.  For LOC
   packaged content, the string codec registrations are defined in Sect
   3 and Section 4 of [WEBCODECS-CODEC-REGISTRY].  For CMAF packaged
   content, the string codec registrations are defined in XXX.

3.2.21.  Mimetype

   A string defining the mime type [MIME] of the track.  This parameter
   is typically supplied with CMAF packaged content.

3.2.22.  Framerate

   A number defining the framerate of the track, expressed as frames per
   second.

3.2.23.  Bitrate

   A number defining the bitrate of track, expressed in bits second.

3.2.24.  Width

   A number expressing the encoded width of the track content in pixels.

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3.2.25.  Height

   A number expressing the encoded height of the video frames in pixels.

3.2.26.  Audio sample rate

   The number of audio frame samples per second.  This property SHOULD
   only accompany audio codecs.

3.2.27.  Channel configuration

   A string specifying the audio channel configuration.  This property
   SHOULD only accompany audio codecs.  A string is used in order to
   provide the flexibility to describe complex channel configurations
   for multi-channel and Next Generation Audio schemas.

3.2.28.  Display width

   A number expressing the intended display width of the track content
   in pixels.

3.2.29.  Display height

   A number expressing the intended display height of the track content
   in pixels.

3.2.30.  Language

   A string defining the dominant language of the track.  The string
   MUST be one of the standard Tags for Identifying Languages as defined
   by [LANG].

3.3.  Catalog Patch

   A catalog update might contain incremental changes.  This is a useful
   property if many tracks may be initially declared but then there are
   small changes to a subset of tracks.  The producer can issue a patch
   to describe these small changes.  Changes are described
   incrementally, meaning that a patch can itself modify a prior patch.
   Patching leverages JSON PATCH [JSON-PATCH] to modify the catalog.
   JSON Patch is a format for expressing a sequence of operations to
   apply to a target JSON document.

   The following rules MUST be followed in processing patches:

   *  The target JSON to be modified is the JSON document described by
      the preceding [MoQTransport] Object in the Catalog track, post any
      patching that may have been applied to that Object.

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   *  A Catalog Patch is identified by having a single array at the root
      level, holding a series of JSON objects, each object representing
      a single operation to be applied to the target JSON document.

   *  Operations are applied sequentially in the order they appear in
      the array.  Each operation in the sequence is applied to the
      target document; the resulting document becomes the target of the
      next operation.  Evaluation continues until all operations are
      successfully applied or until an error condition is encountered.

   *  Track namespaces and track names may not be changed across patch
      updates.  To change either namespace or name, remove the track and
      then add a new track with matching properties and the new
      namespace and name.

   *  Contents of the track selection properties object may not be
      varied across updates.  To adjust a track selection property, the
      track must first be removed and then added with the new selection
      properties and a different name.

3.4.  Catalog Examples

   The following section provides non-normative JSON examples of various
   catalogs compliant with this draft.

3.4.1.  Time-aligned Audio/Video Tracks with single quality

   This example shows catalog for a media producer capable of sending
   LOC packaged, time-aligned audio and video tracks.

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   {
     "version": 1,
     "sequence": 0,
     "streamingFormat": 1,
     "streamingFormatVersion": "0.2",
     "namespace": "conference.example.com/conference123/alice",
     "packaging": "loc",
     "renderGroup": 1,
     "tracks": [
       {
         "name": "video",
         "selectionParams":{"codec":"av01.0.08M.10.0.110.09","width":1920,"height":1080,"framerate":30,"bitrate":1500000}
       },
       {
         "name": "audio",
         "selectionParams":{"codec":"opus","samplerate":48000,"channelConfig":"2","bitrate":32000}
       }
      ]
   }

3.4.2.  Simulcast video tracks - 3 alternate qualities along with audio

   This example shows catalog for a media producer capable of sending 3
   time-aligned video tracks for high definition, low definition and
   medium definition video qualities, along with an audio track.  In
   this example the namesapce is absent, which infers that each track
   must inherit the namespace of the catalog.

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   {
     "version": 1,
     "sequence": 0,
     "streamingFormat": 1,
     "streamingFormatVersion": "0.2",
     "renderGroup": 1,
     "packaging": "loc",
     "tracks":[
       {
         "name": "hd",
         "selectionParams": {"codec":"av01","width":1920,"height":1080,"bitrate":5000000,"framerate":30},
         "altGroup":1
       },
       {
         "name": "md",
         "selectionParams": {"codec":"av01","width":720,"height":640,"bitrate":3000000,"framerate":30},
         "altGroup":1
       },
       {
         "name": "sd",
         "selectionParams": {"codec":"av01","width":192,"height":144,"bitrate":500000,"framerate":30},
         "altGroup":1
       },
       {
         "name": "audio",
         "selectionParams":{"codec":"opus","samplerate":48000,"channelConfig":"2","bitrate":32000},
       }
      ]
   }

3.4.3.  SVC video tracks with 2 spatial and 2 temporal qualities

   This example shows catalog for a media producer capable of sending
   scalable video codec with 2 spatial and 2 temporal layers with a
   dependency relation as shown below:

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                     +----------+
        +----------->|  S1T1    |
        |            | 1080p30  |
        |            +----------+
        |                  ^
        |                  |
   +----------+            |
   |  S1TO    |            |
   | 1080p15  |            |
   +----------+      +-----+----+
         ^           |  SOT1    |
         |           | 480p30   |
         |           +----------+
         |               ^
   +----------+          |
   |  SOTO     |         |
   | 480p15    |---------+
   +----------+

   The corresponding catalog uses "depends" attribute to express the
   track relationships.

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   {
     "version": 1,
     "sequence": 0,
     "streamingFormat": 1,
     "streamingFormatVersion": "0.2",
     "namespace": "conference.example.com/conference123/alice",
     "renderGroup": 1,
     "packaging": "loc",
     "tracks":[
       {
         "name": "480p15",
         "selectionParams": {"codec":"av01.0.01M.10.0.110.09","width":640,"height":480,"bitrate":3000000,"framerate":15},
       },
       {
         "name": "480p30",
         "selectionParams": {"codec":"av01.0.04M.10.0.110.09","width":640,"height":480,"bitrate":3000000,"framerate":30},
         "depends": ["480p15"],
       },
       {
         "name": "1080p15",
         "selectionParams": {"codec":"av01.0.05M.10.0.110.09","width":1920,"height":1080,"bitrate":3000000,"framerate":15},
         "depends":["480p15"]
       },

       {
         "name": "1080p30",
         "selectionParams": {"codec":"av01.0.08M.10.0.110.09","width":1920,"height":1080,"bitrate":5000000,"framerate":30},
         "depends": ["480p30", "1080p15"]
       },
       {
         "name": "audio",
         "selectionParams":{"codec":"opus","samplerate":48000,"channelConfig":"2","bitrate":32000},
       }
      ]
   }

3.4.4.  Patch update adding a track

   This example shows catalog for the media producer adding a slide
   track to an established video conference.

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   [
       {
           "op": "add",
           "path": "/tracks/-",
           "value": {
               "name": "slides",
               "selectionParams": {
                   "codec": "av01.0.08M.10.0.110.09",
                   "width": 1920,
                   "height": 1080,
                   "framerate": 15,
                   "Bitrate": 750000
               },
               "renderGroup": 1
           }
       }
   ]

3.4.5.  Patch update removing a track

   This example shows patch catalog update for a media producer removing
   the track from an established video conference.

   [
     { "op": "remove", "path": "/tracks/2"}
   ]

3.4.6.  Patch update removing all tracks and terminating the broadcast

   This example shows a patch catalog update for a media producer
   removing all tracks and terminating the broadcast.

   [
     { "op": "remove", "path": "/tracks/2"},
     { "op": "remove", "path": "/tracks/1"},
     { "op": "remove", "path": "/tracks/0"},
   ]

3.4.7.  CMAF Tracks with multiple qualities of audio and video

   This example shows catalog for a sports broadcast sending time-
   aligned audio and video tracks using CMAF packaging.  Init segments
   are delivered as separate tracks.

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   {
     "version": 1,
     "sequence": 0,
     "streamingFormat": 1,
     "streamingFormatVersion": "0.2",
     "namespace": "sports.example.com/games/08-08-23/12345",
     "packaging": "cmaf",
     "renderGroup":1,
     "tracks": [
       {
         "name": "video_4k",
         "selectionParams":{"codec":"avc1.640033","mimeType":"video/mp4","width":3840,"height":2160,"framerate":30,"bitrate":14931538},
         "initTrack":"init_video_4k",
         "altGroup": 1
       },
       {
         "name": "video_1080",
         "selectionParams":{"codec":"avc1.640028","mimeType":"video/mp4","width":1920,"height":1080,"framerate":30,"bitrate":9914554},
         "initTrack":"init_video_1080",
         "altGroup": 1
       },
       {
         "name": "video_720",
         "selectionParams":{"codec":"avc1.64001f","mimeType":"video/mp4","width":1280,"height":720,"framerate":30,"bitrate":4952892},
         "initTrack":"init_video_720",
         "altGroup": 1
       },
       {
         "name": "audio_aac",
         "selectionParams":{"codec":"mp4a.40.5","mimeType":"audio/mp4","samplerate":48000,"channelConfig":"2","bitrate":67071},
         "initTrack":"init_audio_aac",
         "altGroup": 2
       },
       {
         "name": "audio_ec3",
         "selectionParms":{"codec":"ec-3","mimeType":"audio/mp4","samplerate":48000,"channelConfig":"F801","bitrate":256000},
         "initTrack":"init_audio_ec3",
         "altGroup": 2
       }
      ]
   }

3.4.8.  Mixed format example - CMAF and LOC packaging in the same
        catalog

   This example shows catalog describing a broadcast with CMAF packaged
   video and LOC packaged audio.

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   {
     "version": 1,
     "sequence": 0,
     "streamingFormat": 1,
     "streamingFormatVersion": "0.2",
     "namespace": "output.example.com/event/12345",
     "renderGroup":1
     "tracks": [
       {
         "name": "video0",
         "selectionParams":{"codec":"avc1.64001f","mimeType":"video/mp4","width":1280,"height":720,"framerate":30,"bitrate":4952892},
         "initTrack":"init_video_720",
         "packaging":"cmaf",
       },
       {
         "name": "audio",
         "selectionParams":{"codec":"opus","samplerate":48000,"channelConfig":"2","bitrate":32000},
         "packaging": "loc",
       }
      ]
   }

3.4.9.  CMAF Tracks with inband init segments

   This example shows catalog for a sports broadcast sending time-
   aligned audio and video tracks using CMAF packaging.  Init segments
   are delivered as inband data.

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   {
     "version": 1,
     "sequence": 0,
     "streamingFormat": 1,
     "streamingFormatVersion": "0.2",
     "namespace": "sports.example.com/games/08-08-23/12345",
     "packaging": "cmaf",
     "renderGroup":1,
     "tracks": [
       {
         "name": "video_1080",
         "selectionParams":{"codec":"avc1.640028","mimeType":"video/mp4","width":1920,"height":1080,"framerate":30,"bitrate":9914554},
   "initData":"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"
       },
       {
         "name": "audio_aac",
         "selectionParams":{"codec":"mp4a.40.5","mimeType":"audio/mp4","samplerate":48000,"channelConfig":"2","bitrate":67071},
   "initData":"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"
       }
      ]
   }

3.4.10.  Time-aligned Audio/Video Tracks with custom field values

   This example shows catalog for a media producer capable of sending
   LOC packaged, time-aligned audio and video tracks along with custom
   fields in each track description.

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   {
     "version": 1,
     "sequence": 0,
     "streamingFormat": 1,
     "streamingFormatVersion": "0.2",
     "namespace": "conference.example.com/conference123/alice",
     "packaging": "loc",
     "renderGroup": 1,
     "tracks": [
       {
         "name": "video",
         "selectionParams":{"codec":"av01.0.08M.10.0.110.09","width":1920,"height":1080,"framerate":30,"bitrate":1500000},
         "com.example-billing-code": 3201,
         "com.example-tier": "premium",
         "com.example-debug": "h349835bfkjfg82394d945034jsdfn349fns"
       },
       {
         "name": "audio",
         "selectionParams":{"codec":"opus","samplerate":48000,"channelConfig":"2","bitrate":32000}
       }
      ]
   }

3.4.11.  A catalog referencing catalogs for two different formats

   This example shows the catalog for a media producer that is
   outputting two streaming formats simultaneously under different
   namespaces.  Note that each track name referenced points at another
   catalog object.

   {
     "version": 1,
     "sequence": 0,
     "catalogs": [
       {
         "name": "catalog-for-format-one",
         "namespace": "sports.example.com/games/08-08-23/live",
         "streamingFormat":1,
         "streamingFormatVersion": "0.2"
       },
       {
         "name": "catalog-for-format-five",
         "namespace": "chat.example.com/games/08-08-23/chat",
         "streamingFormat":5,
         "streamingFormatVersion": "1.6.2"
       }
     ]
   }

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4.  Security Considerations

   The catalog contents MAY be encrypted.  The mechanism of encryption
   and the signaling of the keys are left to the Streaming Format
   referencing this catalog format.

5.  IANA Considerations

   This section details how the MoQ Streaming Format Type can be
   registered.  The type registry can be updated by incrementally
   expanding the type space, i.e., by allocating and reserving new type
   identifiers.  As per [RFC8126], this section details the creation of
   the "MoQ Streaming Format Type" registry.

5.1.  MoQ Streaming Format Type Registry

   This document creates a new registry, "MoQ Streaming Format Type".
   The registry policy is "RFC Required".  The Type value is 2 octets.
   The range is 0x0000-0xFFFF.The initial entry in the registry is:

        +--------+-------------+----------------------------------+
        | Type   |     Name    |            RFC                   |
        +--------+-------------+----------------------------------+
        | 0x0000 |   Reserved  |                                  |
        +--------+-------------+----------------------------------+

   Every MoQ streaming format draft normatively referencing this catalog
   format MUST register itself a unique type identifier.

Acknowledgments

   *  Suhas Nandakumar & Mo Zanaty - this draft
      (https://github.com/suhasHere/moq-drafts/tree/master/moq-catalog).

   *  The IETF MoQ mailing lists and discussion groups.

Normative References

   [BASE64]   Josefsson, S., "The Base16, Base32, and Base64 Data
              Encodings", RFC 4648, DOI 10.17487/RFC4648, October 2006,
              <https://www.rfc-editor.org/rfc/rfc4648>.

   [CMAF]     "Information technology -- Multimedia application format
              (MPEG-A) -- Part 19: Common media application format
              (CMAF) for segmented media", March 2020.

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   [Framemarking]
              Zanaty, M., Berger, E., and S. Nandakumar, "Video Frame
              Marking RTP Header Extension", Work in Progress, Internet-
              Draft, draft-ietf-avtext-framemarking-15, 26 July 2023,
              <https://datatracker.ietf.org/doc/html/draft-ietf-avtext-
              framemarking-15>.

   [JSON]     Bray, T., Ed., "The JavaScript Object Notation (JSON) Data
              Interchange Format", STD 90, RFC 8259,
              DOI 10.17487/RFC8259, December 2017,
              <https://www.rfc-editor.org/rfc/rfc8259>.

   [JSON-PATCH]
              Bryan, P., Ed. and M. Nottingham, Ed., "JavaScript Object
              Notation (JSON) Patch", RFC 6902, DOI 10.17487/RFC6902,
              April 2013, <https://www.rfc-editor.org/rfc/rfc6902>.

   [LANG]     Phillips, A., Ed. and M. Davis, Ed., "Tags for Identifying
              Languages", BCP 47, RFC 5646, DOI 10.17487/RFC5646,
              September 2009, <https://www.rfc-editor.org/rfc/rfc5646>.

   [MIME]     Freed, N., Klensin, J., and T. Hansen, "Media Type
              Specifications and Registration Procedures", BCP 13,
              RFC 6838, DOI 10.17487/RFC6838, January 2013,
              <https://www.rfc-editor.org/rfc/rfc6838>.

   [MoQTransport]
              Curley, L., Pugin, K., Nandakumar, S., and V. Vasiliev,
              "Media over QUIC Transport", Work in Progress, Internet-
              Draft, draft-ietf-moq-transport-01, 23 October 2023,
              <https://datatracker.ietf.org/doc/html/draft-ietf-moq-
              transport-01>.

   [WebCodecs]
              "WebCodecs", July 2023,
              <https://www.w3.org/TR/webcodecs/>.

   [WEBCODECS-CODEC-REGISTRY]
              "WebCodecs Codec Registry", July 2023,
              <https://www.w3.org/TR/webcodecs-codec-registry/>.

Authors' Addresses

   Suhas Nandakumar
   Cisco
   Email: snandaku@cisco.com

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   Will Law
   Akamai
   Email: wilaw@akamai.com

   Mo Zanaty
   Cisco
   Email: mzanaty@cisco.com

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