[AVTCORE] Comments on draft-ietf-avtcore-rtp-vvc-05.txt

[Martin Pettersson M <[e-mail]>]

Hi,

 

Thanks for the good progress on the VVC RTP payload format. Below are some suggested modifications for your consideration:

 

1.	In section 3.2, add “GDR                       Gradual Decoding Refresh”

 

2.	In section 8.4, change “Upon reception of a FIR, a sender must send an IDR picture.” to “Upon reception of a FIR, a sender must send an IDR, a CRA or a GDR picture.”

 

Motivation: 

One of the versatile features in VVC is its support for low-latency coding where the GDR picture is a key component to achieve low latency. Compared to AVC and HEVC where GDR is signaled in an SEI message with optional support by the decoder, the GDR picture in VVC is a normative part of the specification and the decoder must be able to tune in at a GDR picture. Therefore it makes sense to allow a sender to respond with a GDR picture upon receiving a FIR. Note also that a gradual decoding refresh point is mentioned as a possible Decoder Refresh Point in response to the FIR command in https://tools.ietf.org/html/rfc5104.

 

Sending a CRA picture as a response to FIR would be fine as well in my opinion. I don’t see the reason to exclude that.

 

 

3.	In section 9.1, change “The I bit MUST be 1 when the NAL unit type is 7-9 (inclusive), otherwise it MUST be 0.” to “The I bit MUST be 1 when the NAL unit type is 7-10 (inclusive), otherwise it MUST be 0.”

 

In section 9.2, change “The I bit MUST be 1 when the NAL unit type is 7-9 (inclusive), otherwise it MUST be 0.” to “The I bit MUST be 1 when the NAL unit type is 7-10 (inclusive), otherwise it MUST be 0.”

 

Motivation:

NAL unit type 10 is GDR_NUT. 

 

In https://tools.ietf.org/id/draft-ietf-avtext-framemarking-09.html the I bit is specified as:

I: Independent Frame (1 bit) - MUST be 1 for frames that can be decoded independent of temporally prior frames, e.g. intra-frame, VPX keyframe, H.264 IDR [RFC6184], H.265 IDR/CRA/BLA/RAP [RFC7798]; otherwise MUST be 0.

 

The GDR picture is typically not fully refreshed in one frame, but it does not need prior temporal pictures to start the decoding process, i.e. a bitstream that starts with a GDR picture in VVC is a valid bitstream.

 

Best regards,

Martin Pettersson

 

 

From: avt <[e-mail]> On Behalf Of shuaiizhao(Shuai Zhao)
Sent: den 2 november 2020 23:11
To: [e-mail]
Subject: [AVTCORE] FW: I-D Action: draft-ietf-avtcore-rtp-vvc-05.txt(Internet mail)

 

In this revision, Yago’s proposal for SDP parameters were implemented in section 7.2.1.

 

Editor’s notes were added for things we will provide clearfication in next revision.  So do review and critisize lightly. ☺

 

Best

SZ

 

From: avt <[e-mail] <mailto:[e-mail]> > on behalf of "[e-mail] <mailto:[e-mail]> " <[e-mail] <mailto:[e-mail]> >
Reply-To: "[e-mail] <mailto:[e-mail]> " <[e-mail] <mailto:[e-mail]> >
Date: Monday, November 2, 2020 at 14:07
To: "[e-mail] <mailto:[e-mail]> " <[e-mail] <mailto:[e-mail]> >
Cc: "[e-mail] <mailto:[e-mail]> " <[e-mail] <mailto:[e-mail]> >
Subject: [AVTCORE] I-D Action: draft-ietf-avtcore-rtp-vvc-05.txt(Internet mail)

 

 

A New Internet-Draft is available from the on-line Internet-Drafts directories.

This draft is a work item of the Audio/Video Transport Core Maintenance WG of the IETF.

 

        Title           : RTP Payload Format for Versatile Video Coding (VVC)

        Authors         : Shuai Zhao

                          Stephan Wenger

                          Yago Sanchez

                          Ye-Kui Wang

                Filename        : draft-ietf-avtcore-rtp-vvc-05.txt

                Pages           : 61

                Date            : 2020-11-02

 

Abstract:

   This memo describes an RTP payload format for the video coding

   standard ITU-T Recommendation H.266 and ISO/IEC International

   Standard 23090-3, both also known as Versatile Video Coding (VVC) and

   developed by the Joint Video Experts Team (JVET).  The RTP payload

   format allows for packetization of one or more Network Abstraction

   Layer (NAL) units in each RTP packet payload as well as fragmentation

   of a NAL unit into multiple RTP packets.  The payload format has wide

   applicability in videoconferencing, Internet video streaming, and

   high-bitrate entertainment-quality video, among other applications.

 

 

The IETF datatracker status page for this draft is:

https://datatracker.ietf.org/doc/draft-ietf-avtcore-rtp-vvc/

 

There are also htmlized versions available at:

https://tools.ietf.org/html/draft-ietf-avtcore-rtp-vvc-05

https://datatracker.ietf.org/doc/html/draft-ietf-avtcore-rtp-vvc-05

 

A diff from the previous version is available at:

https://www.ietf.org/rfcdiff?url2=draft-ietf-avtcore-rtp-vvc-05

 

 

Please note that it may take a couple of minutes from the time of submission

until the htmlized version and diff are available at tools.ietf.org.

 

Internet-Drafts are also available by anonymous FTP at:

ftp://ftp.ietf.org/internet-drafts/

 

 

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