Request for Publication
Document: RTP Payload Format for Versatile Video Coding (VVC)
Link: https://datatracker.ietf.org/doc/html/draft-ietf-avtcore-rtp-vvc
Intended Status: Proposed Standard
Document Shepard: Bernard Aboba
(1) What type of RFC is being requested (BCP, Proposed Standard, Internet
Standard, Informational, Experimental, or Historic)? Why is this the proper
type of RFC? Is this type of RFC indicated in the title page header?
Proposed Standard.
(2) The IESG approval announcement includes a Document Announcement Write-Up.
Please provide such a Document Announcement Write-Up. Recent examples can be
found in the "Action" announcements for approved documents. The approval
announcement contains the following sections:
Technical Summary:
This document describes the RTP payload format for ITU-T Recommendation
H.266, also know as Versatile Video Coding (VVC). The RTP payload
format, which is applicable to video conferencing, video streaming
and high-bitrate entertainment-quality video, allows for packetization
of Network Abstraction Layer (NAL) units in an RTP packet payload as
well as fragmentation of a NAL unit into multiple RTP packets.
Similar to earlier hybrid-video-coding-based standards, including
HEVC, the following basic video coding design is employed by VVC. A
prediction signal is first formed by either intra- or motion-
compensated prediction, and the residual (the difference between the
original and the prediction) is then coded. The gains in coding
efficiency are achieved by redesigning and improving almost all parts
of the codec over earlier designs. In addition, VVC includes several
tools to make the implementation on parallel architectures easier.
Finally, VVC includes temporal, spatial, and SNR scalability as well
as multiview coding support.
VVC inherits the basic systems and transport interfaces designs from
HEVC and AVC. These include the NAL-unit-based syntax structure, the
hierarchical syntax and data unit structure, the supplemental
enhancement information (SEI) message mechanism, and the video
buffering model based on the hypothetical reference decoder (HRD).
The scalability features of VVC are conceptually similar to the
scalable variant of HEVC known as SHVC.
Working Group Summary:
The VVC payload specification resembles the RTP payload
specification for HEVC (RFC 7798), so discussion in the WG focused
on the differences between the VVC and HEVC codecs and the impact
on the RTP payload format.
The VVC RTP payload specification has been simplified, compared
with HEVC. SDP optional parameters have been reduced.
While HEVC supported SRST, MRST and MRMT transmission
modes, VVC only supports SRST, which has been the most commonly
implemented transmission mode for H.264/SVC and HEVC. As a
result, the VVC RTP payload specification does not require the
tx-mode parameter.
The VVC RTP payload specification also has removed discussion of the
Slice Loss Indication (SLI) and Reference Picture Selection Indication
(RPSI) Feedback Messages, both of which are rarely implemented with
modern codecs.
In addition to these and other simplifications, the WG discussed support
for the Framemarking RTP header extension and concluded that it need not
be supported by the VVC RTP payload specification.
Document Quality:
Are there existing implementations of the protocol? Have a significant number
of vendors indicated their plan to implement the specification? Are there any
reviewers that merit special mention as having done a thorough review, e.g.,
one that resulted in important changes or a conclusion that the document had no
substantive issues? If there was a MIB Doctor, YANG Doctor, Media Type or other
expert review, what was its course (briefly)? In the case of a Media Type
review, on what date was the request posted?
There are existing implementations of the VVC (H.266) encoder and decoder,
including the VVC Test Model. See: https://jvet.hhi.fraunhofer.de/
There is a prototype implementation of the VVC RTP payload specification
covering the mandatory and some optional features of the media plane. There is
no known implementation of the SDP signaling. So far, there have not been any
interop events relating to the VVC RTP payload specification.
There have been no MIB Doctor, Yang Doctor, Media Type or other expert reviews.
Personnel:
Who is the Document Shepherd? Who is the Responsible Area Director?
Document Shepherd is Bernard Aboba. Responsible AD is Murray Kucherawy.
(3) Briefly describe the review of this document that was performed by the
Document Shepherd. If this version of the document is not ready for
publication, please explain why the document is being forwarded to the IESG.
I have reviewed draft -14. Previously, I had reviewed draft-10 and provided
comments here:
https://mailarchive.ietf.org/arch/msg/avt/CNYVIC_3T9VQxpm6r8dnctvFiaU/
The authors responded to my comments:
https://mailarchive.ietf.org/arch/msg/avt/5U2GmOLMCwR6cYgCaC8O1iQjKbo/
(4) Does the document Shepherd have any concerns about the depth or breadth of
the reviews that have been performed?
The specification has not been reviewed by the SDP Directorate.
(5) Do portions of the document need review from a particular or from broader
perspective, e.g., security, operational complexity, AAA, DNS, DHCP, XML, or
internationalization? If so, describe the review that took place.
The document does not raise any unique security, AAA, DNS, DHCP, XML or
internationalization issues.
(6) Describe any specific concerns or issues that the Document Shepherd has
with this document that the Responsible Area Director and/or the IESG should be
aware of? For example, perhaps he or she is uncomfortable with certain parts of
the document, or has concerns whether there really is a need for it. In any
event, if the WG has discussed those issues and has indicated that it still
wishes to advance the document, detail those concerns here.
The VVC RTP payload specification has made a considerable effort to reduce the
number of optional features, including transmission modes and SDP parameters.
This simplification should address some of the interoperability issues
encountered with the HEVC and H.264/SVC RTP payload specifications.
That said, we are still early in the implementation cycle and no
interoperability testing has been done. In the past, organizations such as IMTC
developed profiles as well as producing test suites and organizing interop
events. However, the IMTC (since merged into MEF) has no current plans to
update the HEVC RTP profile for VVC:
https://www.mef.net/wp-content/uploads/2020/09/IMTC1016_22034_1.pdf
(7) Has each author confirmed that any and all appropriate IPR disclosures
required for full conformance with the provisions of BCP 78 and BCP 79 have
already been filed. If not, explain why?
On March 8, a request for author confirmation was posted to the mailing list:
https://mailarchive.ietf.org/arch/msg/avt/s4qv9h6osUBw9GCMux8cSRu1tJM/
A response was received from each of the authors:
Shuai Zhao:
https://mailarchive.ietf.org/arch/msg/avt/z-squBK_9cc1Ebtb5ZUoVANmw6Q/ Stephan
Wenger: https://mailarchive.ietf.org/arch/msg/avt/_LBJVphT1RRtHCR-p3Mvi1Opu8Y/
Yago Sanchez de la Fuente:
https://mailarchive.ietf.org/arch/msg/avt/sDovNWZ5CZ-z7mwnv6ygZFJk7x8/ Ye-Kui
Wang: https://mailarchive.ietf.org/arch/msg/avt/s6rJHDcLHq9pgyGZGrBFqx6jxvs/
Miska Hannuksela:
https://mailarchive.ietf.org/arch/msg/avt/hn0YMTDYVrqmNVjmvs1kBS1XgEY/
(8) Has an IPR disclosure been filed that references this document? If so,
summarize any WG discussion and conclusion regarding the IPR disclosures.
Multiple IPR declarations have been filed:
https://datatracker.ietf.org/ipr/search/?submit=draft&id=draft-ietf-avtcore-rtp-vvc
WG discussion on whether to proceed to publication was requested on March 8,
2022: https://mailarchive.ietf.org/arch/msg/avt/vH-1ZgsF0EMBqIUy64apLQqLl78/
No objections have been sent to the list, nor were any objections raised when
the issue was brought up at the IETF 113 AVTCORE WG meeting.
(9) How solid is the WG consensus behind this document? Does it represent the
strong concurrence of a few individuals, with others being silent, or does the
WG as a whole understand and agree with it?
WG consensus behind this document appears solid. A summary of the
second WGLC is here:
https://mailarchive.ietf.org/arch/msg/avt/g5uv_hrfZtPJmJFEWQaHKDwHFqY/
7 responses to the WGLC announcement were received. Of the responses,
6 favored publication "as is" and 1 provided comments. There were no
objections.
*"As is"*
Stephan Wenger:
https://mailarchive.ietf.org/arch/msg/avt/354RgFgb4EWmQFsFNSC41LDls4M/
Sanchez de la Fuente:
https://mailarchive.ietf.org/arch/msg/avt/S8cY3yBtFmbCYc6n8JrfZ_iddxg/
Ye-Kui Wang:
https://mailarchive.ietf.org/arch/msg/avt/9p3ziA8t9d06U7wnCU5qiNd933A/
Shuai Zhao:
https://mailarchive.ietf.org/arch/msg/avt/3nKG5jR_phMtHBECrjHwgf7am5Q/
Miska Hannuksela:
https://mailarchive.ietf.org/arch/msg/avt/3Kb2VCLGUQLwsPeL8pUW2YhWIXg/
Thomas Schierl:
https://mailarchive.ietf.org/arch/msg/avt/XCzdnL3uonjTZMkgWGdlIhAyCyg/
*Comments provided:*
Mach Chen:
https://mailarchive.ietf.org/arch/msg/avt/PWJ2ZsBwolsHxGiWu-wwfIAOX38/
Response from Stephan:
https://mailarchive.ietf.org/arch/msg/avt/u40nDpFsD7JveHLu-mkW5wi-PH8/
Response from Mach:
https://mailarchive.ietf.org/arch/msg/avt/3b2FktXkhYzx3Cd1tXKFUh4J_K0/
Response from Stephan:
The authors addressed the comments in draft -14.
(10) Has anyone threatened an appeal or otherwise indicated extreme discontent?
If so, please summarise the areas of conflict in separate email messages to the
Responsible Area Director. (It should be in a separate email because this
questionnaire is publicly available.)
No appeal threats or extreme discontent expressed.
(11) Identify any ID nits the Document Shepherd has found in this document.
(See http://www.ietf.org/tools/idnits/ and the Internet-Drafts Checklist).
Boilerplate checks are not enough; this check needs to be thorough.
An ID nits run on -14 discloses 0 errors, 0 flaws and 1 warning:
idnits 2.17.00 (12 Aug 2021)
/tmp/idnits1001/draft-ietf-avtcore-rtp-vvc-14.txt:
/tmp/idnits1001/draft-ietf-avtcore-rtp-vvc-14.txt(3591): Found non-ascii
character (Ã) in position 10.
Checking boilerplate required by RFC 5378 and the IETF Trust (see
https://trustee.ietf.org/license-info):
----------------------------------------------------------------------------
No issues found here.
Checking nits according to https://www.ietf.org/id-info/1id-guidelines.txt:
----------------------------------------------------------------------------
== There is 1 instance of lines with non-ascii characters in the document.
Checking nits according to https://www.ietf.org/id-info/checklist :
----------------------------------------------------------------------------
No issues found here.
Miscellaneous warnings:
----------------------------------------------------------------------------
-- The document date (25 February 2022) is 19 days in the past. Is this
intentional?
Checking references for intended status: Proposed Standard
----------------------------------------------------------------------------
(See RFCs 3967 and 4897 for information about using normative references
to lower-maturity documents in RFCs)
-- Looks like a reference, but probably isn't: '0' on line
1390
'transmission order), AbsDon[0] is set equal to DON[0]....'
-- Possible downref: Non-RFC (?) normative reference: ref. 'ISO23090-3'
-- Possible downref: Non-RFC (?) normative reference: ref. 'VSEI'
-- Possible downref: Non-RFC (?) normative reference: ref. 'VVC'
Summary: 0 errors (**), 0 flaws (~~), 1 warning (==), 5 comments (--).
(12) Describe how the document meets any required formal review criteria, such
as the MIB Doctor, YANG Doctor, media type, and URI type reviews.
The document contains no MIBs or YANG modules and does not define URI types. It
does define a media type.
(13) Have all references within this document been identified as either
normative or informative?
Yes.
(14) Are there normative references to documents that are not ready for
advancement or are otherwise in an unclear state? If such normative references
exist, what is the plan for their completion?
There are references to non-IETF documents, such as the VVC specification:
https://www.itu.int/rec/T-REC-H.266
There are no normative references to documents not ready for advancement or in
an unclear state.
However, there is one Informative reference that appears improperly formatted,
to [CABAC].
(15) Are there downward normative references references (see RFC 3967)? If so,
list these downward references to support the Area Director in the Last Call
procedure.
No.
(16) Will publication of this document change the status of any existing RFCs?
Are those RFCs listed on the title page header, listed in the abstract, and
discussed in the introduction? If the RFCs are not listed in the Abstract and
Introduction, explain why, and point to the part of the document where the
relationship of this document to the other RFCs is discussed. If this
information is not in the document, explain why the WG considers it unnecessary.
The publication of this document will not change the status of any existing
RFCs.
(17) Describe the Document Shepherd's review of the IANA considerations
section, especially with regard to its consistency with the body of the
document. Confirm that all protocol extensions that the document makes are
associated with the appropriate reservations in IANA registries. Confirm that
any referenced IANA registries have been clearly identified. Confirm that newly
created IANA registries include a detailed specification of the initial
contents for the registry, that allocations procedures for future registrations
are defined, and a reasonable name for the new registry has been suggested (see
RFC 8126).
The document requests allocation of a new media type in Section 7.1. AFAICT the
request is consistent with the rest of the document.
(18) List any new IANA registries that require Expert Review for future
allocations. Provide any public guidance that the IESG would find useful in
selecting the IANA Experts for these new registries.
No new IANA registries are established by the document.
(19) Describe reviews and automated checks performed by the Document Shepherd
to validate sections of the document written in a formal language, such as XML
code, BNF rules, MIB definitions, YANG modules, etc.
No formal languages used.
(20) If the document contains a YANG module, has the module been checked with
any of the recommended validation tools
(https://trac.ietf.org/trac/ops/wiki/yang-review-tools) for syntax and
formatting validation? If there are any resulting errors or warnings, what is
the justification for not fixing them at this time? Does the YANG module comply
with the Network Management Datastore Architecture (NMDA) as specified in
RFC8342?
No YANG modules.