H.265 Profile for WebRTC
draft-aboba-avtcore-hevc-webrtc-00

AVTCORE Working Group                                           B. Aboba
INTERNET-DRAFT                                     Microsoft Corporation
Category: Informational
Expires: October 11, 2023                                  11 April 2023

                        H.265 Profile for WebRTC
                 draft-aboba-avtcore-hevc-webrtc-00.txt

Abstract

   RFC 7742 defines WebRTC video processing and codec requirements,
   including guidance for endpoints supporting the VP8 and H.264 codecs,
   which are mandatory to implement.  With support for H.265 under
   development in WebRTC browsers, the need has arisen to provide
   similar guidance for browsers desiring to support the (optional)
   H.265 codec, whose RTP payload format is defined in RFC 7798.

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
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   Drafts is at http://datatracker.ietf.org/drafts/current/.

   Internet-Drafts are draft documents valid for a maximum of six months
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   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 October 11, 2023.

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Copyright Notice

   Copyright (c) 2023 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  . . . . . . . . . . . . . . . . . . . . . . . .   3
     1.1.  Terminology . . . . . . . . . . . . . . . . . . . . . . .   3
   2.  H.265 Support . . . . . . . . . . . . . . . . . . . . . . . .   3
   3.  Security Considerations . . . . . . . . . . . . . . . . . . .   4
   4.  IANA Considerations . . . . . . . . . . . . . . . . . . . . .   4
   5. References . . . . . . . . . . . . . . . . . . . . . . . . . .   4
     5.1.  Normative References  . . . . . . . . . . . . . . . . . .   4
     5.2.  Informative References  . . . . . . . . . . . . . . . . .   5
   Acknowledgments   . . . . . . . . . . . . . . . . . . . . . . . .   5
   Authors' Addresses  . . . . . . . . . . . . . . . . . . . . . . .   5

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1.  Introduction

   "RTP Payload Format for High Efficiency Video Coding (HEVC)"
   [RFC7798] defines the encapsulation of H.265 within the Real-time
   Transport Protocol (RTP).  While "WebRTC Video Processing and Codec
   Requirements" [RFC7742] provides guidance for endpoints supporting
   the mandatory to implement VP8 and H.264 codecs, it does not cover
   H.265. With H.265 support under development within WebRTC browsers,
   the need has arisen to profile [RFC7798] for WebRTC implementations
   choosing to support H.265.

1.1.  Terminology

   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.

2.  H.265 Support

   WebRTC browsers and non-browsers MAY implement the H.265 video codec
   as described in [RFC7798] and [HEVC]. WebRTC browsers and non-
   browsers supporting H.265 MUST support receiving, and MAY support the
   ability to send H.265.

   For the [HEVC] codec, endpoints MUST support the payload formats
   defined in [RFC7798].  In addition, they MUST support Main Profile
   Level 3.1 (level-id=93) and SHOULD support Main Profile Level 4
   (level-id=120).

   Implementations of the HEVC codec have utilized a wide variety of
   optional parameters.  To improve interoperability, the following
   parameter settings are specified:

   level-id:  Implementations MUST include this parameter within SDP and
   MUST interpret it when receiving it.

   max-fps, max-cpb, max-dpb, and max-br:

   These parameters allow the implementation to specify that they can
   support certain features of HEVC at higher rates and values than
   those signaled by their level (set with level-id).  Implementations
   MAY include these parameters in their SDP, but they SHOULD interpret
   them when receiving them, allowing them to send the highest quality
   of video possible.

   sprop-vps, sprop-sps, sprop-pps, sprop-sei: HEVC allows sequence and

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   picture information to be sent both in-band and out-of-band.  WebRTC
   implementations MUST signal this information in-band.  This means
   that WebRTC implementations MUST NOT include these parameters in the
   SDP they generate.

   When the use of the video orientation (CVO) RTP header extension is
   not signaled as part of the SDP, H.265 implementations MAY send and
   SHOULD support proper interpretation of Display Orientation SEI
   messages.

   Unless otherwise signaled, implementations that use H.265 MUST encode
   and decode pixels with an implied 1:1 (square) aspect ratio.

3.  Security Considerations

   This document is subject to the security considerations described in
   Section 7 of [RFC7742].

   In addition to those security considerations, H.265 implementers are
   advised to take note of the "Security Considerations" Section 9 of
   [RFC7798], including requirements pertaining to SEI messages.

4.  IANA Considerations

   This document does not require actions by IANA.

5.  References

5.1.  Normative References

[HEVC]       ITU-T, "High efficiency video coding", ITU-T Recommendation
             H.265, April 2013.

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

[RFC3550]    Schulzrinne, H., Casner, S., Frederick, R., and V.
             Jacobson, "RTP: A Transport Protocol for Real-Time
             Applications", STD 64, RFC 3550, DOI 10.17487/RFC3550, July
             2003, <http://www.rfc-editor.org/info/rfc3550>.

[RFC3711]    Baugher, M., McGrew, D., Naslund, M., Carrara, E., and K.
             Norrman, "The Secure Real-time Transport Protocol (SRTP)",
             RFC 3711, DOI 10.17487/RFC3711, March 2004,
             <http://www.rfc-editor.org/info/rfc3711>.

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[RFC7798]    Wang, Y.K., Sanchez, Y., Schierl, T., Wenger, S. and M. M.
             Hannuksela, "RTP Payload Format for High Efficiency Video
             Coding (HEVC)", RFC 7798, DOI 10.17487/RFC7798, March 2016,
             <https://www.rfc-editor.org/info/rfc7798>.

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

5.2.  Informative References

[RFC7742]    Roach, A. B., "WebRTC Video Processing and Codec
             Requirements", RFC 7742, DOI 10.17487/RFC7742, March 2016,
             <https://www.rfc-editor.org/info/rfc7742>.

Acknowledgments

   We would like to thank Stefan Wenger, Philipp Hancke, and Harald
   Alvestrand for their discussions of this problem space.

Authors' Addresses

   Bernard Aboba
   Microsoft Corporation
   One Microsoft Way
   Redmond, WA  98052
   United States of America

   Email:  bernard.aboba@gmail.com

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