Video Codec Requirements and Evaluation Methodology
draft-ietf-netvc-requirements-10

Thank you for addressing my DISCUSS and COMMENT items.

Thank you all for the work put into this document. Most of the content was way above my technical knowledge though; I would appreciate a reply to the two comments below.

== COMMENTS ==

-- Section 2.1 --

Please expand/explain 'PAM', 'RA', 'EDTV', ... before first use in table 1.

-- Section 4 --

This section is only on 'compression performance' and as I read it about compression ratio and nothing is said about packet-loss robustness which is identified in previous section as important. Am I missing something ?


-éric

Please respond to the Gen-ART review.

I think sections 4.2 and 6 should be removed.

§4.2 mentions "Reference software provided to the NETVC WG for candidate codecs", but, if I understand correctly, the WG will not evaluate the candidates.

Clearing my Discuss as we had a brief discussion on the IESG telechat, and
the responsible AD will follow the discussion with the tsvart reviewer.

Original Discuss portion:

I support Roman's Discuss.

I am sympathetic to the tsv-art reviewer's concerns that this document
is focused on video technology of 5 years ago and may lack relevant in
the current world.  I don't intend to hold a Discuss point for any
specific resolution, but I do think the IESG should discuss whether this
concern affects the value of publishing this document as an RFC.

%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%

Original Comment portion (unchanged)

Section 2.1

What do "PAM" and "RA" mean?  Moving Appendix A earlier (before Section
2) or referring to it from the Introduction would be helpful.  Note that
RFC style is to expand on first use...

       . High Dynamic Range (HDR), Wide Color Gamut (WCG), high
          resolution (currently, up to 4K), high frame-rate content are
          important use cases, the codec should be able to encode such
          content efficiently.

nits: missing "and" in serial list, and the last comma is a comma splice.

Section 2.5

[Google didn't help me find reference [9].]

Section 2.6

The (long) list in Section 2.5 includes "cloud gaming"; how much overlap
does that have with this service?

Section 3.1, 3.2

What is the difference between "General Requirements" and "Basic
Requirements"?

ection 3.2.1

Is "Exemplary input source formats" supposed to just be an example, or
an indication of the pinnacle of possible values?

Section 4.1

   Initially, for the codec selected as a reference one (e.g., HEVC or
   VP9), a set of 10 QP (quantization parameter) values should be
   specified (in a separate document on Internet video codec testing)
   and corresponding quality values should be calculated. [...]

This seems to suggest ("Initially", "for the codec selected") that the
evaulation requirements are not yet complete.  Are they intended to be a
single set of requirements for the codec's development, or customized to
some per-application requirements?  (Is there a reference needed to
ongoing work to solidify these requirements?)

   QP'k = argmin { abs(Q'i(QP'i) - Qk(QPk)) },
          i in R

I would suggest defining the argmin function.

It's surprising to see no reference to draft-ietf-netvc-testing from
this document.

Section 6

I don't see much need for a "Conclusions" section of this nature, in
this document.

Appendix B

Defining (e.g.) "high dynamic range" and "wide color gamut" with respect
to "normal" or "conventional" mechanisms does not really provide a
stable and archival reference for comparison.