Subject: [Gen-art] Gen-ART Review of draft-ietf-rtcweb-video-05

From: Russ Housley <[email-masked]>
Date: Fri, 15 May 2015 11:14:13 -0400

I am the assigned Gen-ART reviewer for this draft. For background on
Gen-ART, please see the FAQ at
<http://wiki.tools.ietf.org/area/gen/trac/wiki/GenArtfaq>.

This review is in response to a request for early Gen-ART review.

Document: draft-ietf-rtcweb-video-05
Reviewer: Russ Housley
Review Date: 2015-05-15
IETF LC End Date: 2015-04-28
IESG Telechat date: unknown

Summary: Almost Ready

Major Concerns:

Downref: There is a normative reference to Informational RFC 6386.
There is no mention of the downref in the IETF Last Call, and
RFC 6386 is not listed in the downref registry.
(https://trac.tools.ietf.org/group/iesg/trac/wiki/DownrefRegistry).

Minor Concerns:

In section 3, the first sentence says: "This section provides guidance
on pre- or post-processing of video streams."  s/pre- or/pre- and/

Maybe the intended audience will understand "Y'CbCr 4:2:0", but a
reference would have helped me.  I found useful information at
http://en.wikipedia.org/wiki/Chroma_subsampling.

The indented text in Section 5 should begin with "NOTE: ".

In section 6, I assume that "320x240" is measured in pixels.  Please
make the text clear.

Section 6.2 says: "Unless otherwise signaled, implementations that use
H.264 MUST encode and decode pixels with a implied 1:1 (square) aspect
ratio."  Isn't this true for VP8 as well?

Other Comments:

There are references to several outdated I-Ds.  Some of the references
point to particular section numbers.  I did not check whether the
updates had an impact on these sections, but someone should do so:
  - draft-ietf-payload-vp8-11: -15 exists
  - draft-ietf-rtcweb-overview-12: -13 exists
  - draft-ietf-rtcweb-rtp-usage-06: -23 exists
  - draft-ietf-rtcweb-security-arch-09: -11) exists
  - draft-ietf-rtcweb-security-06: -08 exists