Subject: [video-codec] WG Last Call for comments on Requirements draft

From: "Mo Zanaty (mzanaty)" <[email-masked]>
Date: Tue, 2 May 2017 14:44:29 +0000

This email announces a NETVC Working Group Last Call (WGLC) for comments on draft-ietf-netvc-requirements-06<https://datatracker.ietf.org/doc/draft-ietf-netvc-requirements/>.

Please review and send comments to the list (or just authors and chairs) by May 16.

A summary of the recent changes is included below.

Thanks,
Mo

-----Original Message-----
From: video-codec <[email-masked]<mailto:[email-masked]>> on behalf of Filippov Alexey <[email-masked]<mailto:[email-masked]>>
Date: Friday, April 28, 2017 at 7:24 AM
To: "[email-masked]<mailto:[email-masked]>" <[email-masked]<mailto:[email-masked]>>, netvc-chairs <[email-masked]<mailto:[email-masked]>>
Cc: "Timothy B. Terriberry" <[email-masked]<mailto:[email-masked]>>, Thomas Daede <[email-masked]<mailto:[email-masked]>>, Andrey Norkin <[email-masked]<mailto:[email-masked]>>, Jose Alvarez <[email-masked]<mailto:[email-masked]>>, Zhoujiantong <[email-masked]<mailto:[email-masked]>>
Subject: [video-codec] Version -06 of the requirements draft

Dear colleagues,

Today, version -06 of the requirements draft was published. The only change in the document is in Section 3.1.1. The sentence
"3.1.1:The most basic requirement is coding efficiency, i.e. compression performance on both "easy" and "difficult" natural content as well as screen sharing content (both static and dynamic)."
was replaced by
"3.1.1:The most basic requirement is coding efficiency, i.e. compression performance on both "easy" and "difficult" content for applications and use cases in Section 2."
It is done to keep the requirements draft consistent with the testing draft where different content is used for estimating compression performance.

In addition, we (the authors of the requirements draft) would like to comment on the changes appeared in version -05 of the document and discussed at the meeting in Chicago.

3.1.3: Bitstream syntax should allow extensibility and backward compatibility. New features can be supported easily by using metadata (e.g., such as SEI messages, VUI, headers) without affecting the bitstream compatibility with legacy decoders. A newer version of the decoder shall be able to play bitstreams of an older version of the same or lower profile and level.
Our comment: In fact, this requirement was contained in the previous versions of the draft (starting from version -02). In particular, SEI messages, VUI and headers were mentioned there. To clarify this point, it is NOT a requirement that a new version of the codec with new coding tools has to support the older versions of that codec. It merely states that extending the current codec with support of new metadata, such as video source information etc, should not break compatibility with older bitstreams of the same codec. That is, the syntax for signaling metadata should be extensible and adding new metadata should not break compatibility with older decoders. The decoders should just ignore metadata they do not understand.

Minor changes in Section 3.2.2. "Coding delay": Support of efficient random access point encoding (such as intra coding and resetting of context variables) as well as efficient switching between multiple quality representations.
Our comment: This requirement was in the description of the use cases in the document (e.g., in section 2.1 "Internet Video Streaming"), now it is also explicitly mentioned in the requirements

3.2.3. Complexity: Feasible real-time implementation of both an encoder and a decoder supporting a chosen subset of tools for hardware and software implementation on a wide range of state-of-the-art platforms. The real-time encoder tools subset should provide meaningful improvement in compression efficiency at reasonable complexity of hardware and software encoder implementations as compared to current real-time implementations of state-of-the-art video compression technologies such as HEVC/H.265 and VP9.
Our comment: This is just a clarification regarding what a feasible real-time implementation means.

Your further questions and comments are welcome!

--
Best regards,
Alexey Filippov

-----Original Message-----
From: "[email-masked]" <[email-masked]>
Date: Friday, April 28, 2017 at 6:54 AM
Subject: New Version Notification for draft-ietf-netvc-requirements-06.txt

A new version of I-D, draft-ietf-netvc-requirements-06.txt
has been successfully submitted by Alexey Filippov and posted to the
IETF repository.

Name: draft-ietf-netvc-requirements
Revision: 06
Title: <Video Codec Requirements and Evaluation Methodology>
Document date: 2017-04-28
Group: netvc
Pages: 25
URL:            https://www.ietf.org/internet-drafts/draft-ietf-netvc-requirements-06.txt
Status:         https://datatracker.ietf.org/doc/draft-ietf-netvc-requirements/
Htmlized:       https://tools.ietf.org/html/draft-ietf-netvc-requirements-06
Htmlized:       https://datatracker.ietf.org/doc/html/draft-ietf-netvc-requirements-06
Diff:           https://www.ietf.org/rfcdiff?url2=draft-ietf-netvc-requirements-06

Abstract:
   This document provides requirements for a video codec designed
   mainly for use over the Internet. In addition, this document
   describes an evaluation methodology needed for measuring the
   compression efficiency to ensure whether the stated requirements are
   fulfilled or not.

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

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