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WARP Streaming Format
draft-law-moq-warpstreamingformat-01

Document Type Active Internet-Draft (individual)
Authors Will Law , Luke Curley , Victor Vasiliev , Suhas Nandakumar , Kirill Pugin
Last updated 2024-01-22
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draft-law-moq-warpstreamingformat-01
Media Over QUIC                                                   W. Law
Internet-Draft                                                    Akamai
Intended status: Informational                                 L. Curley
Expires: 25 July 2024                                             Twitch
                                                             V. Vasiliev
                                                                  Google
                                                           S. Nandakumar
                                                                   Cisco
                                                                K. Pugin
                                                                    Meta
                                                         22 January 2024

                         WARP Streaming Format
                  draft-law-moq-warpstreamingformat-01

Abstract

   This document specifies the WARP Streaming Format, designed to
   operate on Media Over QUIC Transport.

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/MoQ/draft-law-moq-warpmedia.html.  Status
   information for this document may be found at
   https://datatracker.ietf.org/doc/draft-law-moq-warpstreamingformat/.

   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/MoQ.

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/.

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   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 25 July 2024.

Copyright Notice

   Copyright (c) 2024 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 Revised BSD License text as
   described in Section 4.e of the Trust Legal Provisions and are
   provided without warranty as described in the Revised BSD License.

Table of Contents

   1.  Introduction  . . . . . . . . . . . . . . . . . . . . . . . .   2
   2.  Conventions and Definitions . . . . . . . . . . . . . . . . .   3
   3.  Media packaging . . . . . . . . . . . . . . . . . . . . . . .   3
     3.1.  Packaging mode  . . . . . . . . . . . . . . . . . . . . .   3
     3.2.  Time-alignment  . . . . . . . . . . . . . . . . . . . . .   4
     3.3.  Content protection and encryption . . . . . . . . . . . .   4
   4.  Catalog . . . . . . . . . . . . . . . . . . . . . . . . . . .   4
   5.  Media transmission  . . . . . . . . . . . . . . . . . . . . .   5
   6.  Workflow  . . . . . . . . . . . . . . . . . . . . . . . . . .   5
   7.  Security Considerations . . . . . . . . . . . . . . . . . . .   5
   8.  IANA Considerations . . . . . . . . . . . . . . . . . . . . .   5
   9.  Normative References  . . . . . . . . . . . . . . . . . . . .   5
   Acknowledgments . . . . . . . . . . . . . . . . . . . . . . . . .   7
   Authors' Addresses  . . . . . . . . . . . . . . . . . . . . . . .   7

1.  Introduction

   WARP Streaming Format (WARP) is a media format designed to deliver
   CMAF [CMAF] compliant media content over Media Over QUIC Transport
   (MOQT) [MoQTransport].  WARP works by fragmenting the bitstream into
   objects that can be independently transmitted.  WARP leverages a
   simple prioritization strategy of assigning newer content a higher
   delivery order, allowing intermediaries to drop older data, and video
   over audio, in the face of congestion.  Either complete Groups of
   Pictures (GOPS) [ISOBMFF] or individual frames are mapped to

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   MoQTransport Objects.  WARP is targeted at interactive levels of live
   latency.

   This document describes version 1 of the streaming format.

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
   BCP 14 [RFC2119] [RFC8174] when, and only when, they appear in all
   capitals, as shown here.

   This document uses the conventions detailed in Section 1.3 of
   [RFC9000] when describing the binary encoding.

3.  Media packaging

   WARP delivers CMAF-packaged media bitstreams.  This specification
   references [CMAFpackaging] to define how CMAF packaged bitstreams are
   mapped to [MoQTransport] groups and objects.

   Both CMAF Object mappings [CMAFpackaging] Section 4 are supported and
   a content producer may use either.  To identify to consumers which
   object mapping mode is being used for a given Track, a new track
   field is defined as per table 1.

   +===========+================+========+========+======+============+
   | Field     | Name           |Required|Location|JSON  | Definition |
   |           |                |        |        |type  |            |
   +===========+================+========+========+======+============+
   | WARP      | warp-packaging |yes     |RT      |String| See        |
   | packaging |                |        |        |      | Section    |
   | mode      |                |        |        |      | 3.1        |
   +-----------+----------------+--------+--------+------+------------+

                                 Table 1

3.1.  Packaging mode

   The packaging mode value is defined by Table 2.

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    +==================+=================+============================+
    | warp-packing     | Condition       | Explanation                |
    | field value      |                 |                            |
    +==================+=================+============================+
    | frag-per-group   | [CMAFpackaging] | Each CMAF Fragment is      |
    |                  | 4.1 is active   | placed in a single MOQT    |
    |                  |                 | Object and there is one    |
    |                  |                 | MOQT Object per MOQT Group |
    +------------------+-----------------+----------------------------+
    | chunk-per-object | [CMAFpackaging] | Each CMAF chunk is placed  |
    |                  | 4.2 is active   | in a MOQT Object and there |
    |                  |                 | is one MOQT Group per CMAF |
    |                  |                 | Fragment                   |
    +------------------+-----------------+----------------------------+

                                  Table 2

3.2.  Time-alignment

   WARP Tracks MAY be time-aligned.  Those that are, are subject to the
   following requirements:

   *  Time-aligned tracks MUST be advertised in the catalog as belonging
      to a common render group.

   *  The presentation time of the first media sample contained within
      the first MOQT Object of each equally numbered MOQT Group MUST be
      identical.

   A consequence of this restriction is that a WARP receiver SHOULD be
   able to cleanly switch between time-aligned media tracks at group
   boundaries.

3.3.  Content protection and encryption

   The catalog and media object payloads MAY be encrypted.  Common
   Encryption [CENC] with 'cbcs' mode (AES CBC with pattern encryption)
   is the RECOMMENDED encryption method.

   ToDo - details of how keys are exchanged and license servers
   signaled.  May be best to extend catalog spec to allow the
   specification of content protection schema, along with any pssh or
   protection initialization data.

4.  Catalog

   WARP uses the Common Catalog Format {[COMMON-CATALOG-FORMAT}} to
   describe the content being produced by a publisher.

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   Per Sect 5.1 of [COMMON-CATALOG-FORMAT], WARP registers an entry in
   the "MoQ Streaming Format Type" table.  The type value is 0x001, the
   name is "WARP Streaming Format" and the RFC is XXX.

   Every WARP catalog MUST declare a streaming format type (See Sect
   3.2.1 of [COMMON-CATALOG-FORMAT]) value of 1.

   Every WARP catalog MUST declare a streaming format version (See Sect
   3.2.1 of [COMMON-CATALOG-FORMAT]) corresponding to the version of
   this document.

   The catalog track MUST have a track name of "catalog".  A catalog
   object MAY be independent of other catalog objects or it MAY
   represent a delta update of a prior catalog object.  The first
   catalog object published within a new group MUST be independent.  A
   catalog object SHOULD only be published only when the availability of
   tracks changes.

   Each catalog update MUST be mapped to a discreet moq-transport
   object.

5.  Media transmission

   The MOQT Groups and MOQT Objects need to be mapped to moq-transport
   Streams.  Irrespective of the Section 3.1 in place, each MOQT Object
   MUST be mapped to a new moq-transport Stream.

6.  Workflow

   A WARP publisher MUST publish a catalog track object before
   publishing any media track objects.

   At the completion of a session, a publisher MUST publish a catalog
   update that removes all currently active tracks.  This action SHOULD
   be interpreted by receivers to mean that the publish session is
   complete.

7.  Security Considerations

   ToDo

8.  IANA Considerations

   This document creates a new entry in the "MoQ Streaming Format"
   Registry (see [MoQTransport] Sect 8).  The type value is 0x001, the
   name is "WARP Streaming Format" and the RFC is XXX.

9.  Normative References

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   [CENC]     "International Organization for Standardization -
              Information technology - MPEG systems technologies - Part
              7: Common encryption in ISO base media file format files",
              December 2020.

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

   [CMAFpackaging]
              Law, W. and L. Curley, "CMAF Packaging for moq-transport",
              Work in Progress, Internet-Draft, draft-wilaw-moq-
              cmafpackaging-00, 2 October 2023,
              <https://datatracker.ietf.org/doc/html/draft-wilaw-moq-
              cmafpackaging-00>.

   [COMMON-CATALOG-FORMAT]
              "Common Catalog Format for moq-transport", September 2023,
              <https://wilaw.github.io/catalog-format/draft-wilaw-moq-
              catalogformat.html>.

   [ISOBMFF]  "Information technology -- Coding of audio-visual objects
              -- Part 12: ISO Base Media File Format", December 2015.

   [MoQTransport]
              Curley, L., Pugin, K., Nandakumar, S., and V. Vasiliev,
              "Media over QUIC Transport", Work in Progress, Internet-
              Draft, draft-lcurley-moq-transport-00, 26 May 2023,
              <https://datatracker.ietf.org/doc/html/draft-lcurley-moq-
              transport-00>.

   [RFC2119]  Bradner, S., "Key words for use in RFCs to Indicate
              Requirement Levels", BCP 14, RFC 2119,
              DOI 10.17487/RFC2119, March 1997,
              <https://www.rfc-editor.org/rfc/rfc2119>.

   [RFC8174]  Leiba, B., "Ambiguity of Uppercase vs Lowercase in RFC
              2119 Key Words", BCP 14, RFC 8174, DOI 10.17487/RFC8174,
              May 2017, <https://www.rfc-editor.org/rfc/rfc8174>.

   [RFC9000]  Iyengar, J., Ed. and M. Thomson, Ed., "QUIC: A UDP-Based
              Multiplexed and Secure Transport", RFC 9000,
              DOI 10.17487/RFC9000, May 2021,
              <https://www.rfc-editor.org/rfc/rfc9000>.

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Acknowledgments

   *  Alan Frindell

   *  Ali Begen

   *  Charles Krasic

   *  Christian Huitema

   *  Cullen Jennings

   *  Hang Shi

   *  James Hurley

   *  Jordi Cenzano

   *  Mike English

   *  the MoQ Workgroup and mailing lists.

Authors' Addresses

   Will Law
   Akamai
   Email: wilaw@akamai.com

   Luke Curley
   Twitch
   Email: kixelated@gmail.com

   Victor Vasiliev
   Google
   Email: vasilvv@google.com

   Suhas Nandakumar
   Cisco
   Email: snandaku@cisco.com

   Kirill Pugin
   Meta
   Email: ikir@meta.com

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