Subject: [codec] Benjamin Kaduk's No Objection on draft-ietf-codec-ambisonics-07: (with COMMENT)

From: Benjamin Kaduk <[email-masked]>
Date: Mon, 30 Jul 2018 12:35:14 -0700

Benjamin Kaduk has entered the following ballot position for
draft-ietf-codec-ambisonics-07: No Objection

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COMMENT:
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I see that Section 5.2 attempts to Update RFC 7845 to allow for the larger
channel mapping information used by family 3, but I'm still a little
unclear about what behavior I should expect from a pure RFC 7845
implementation that receives a family 3 stream.  The actual mapping table
would be "too long", but would the implementation detect that, or just note
that it's an unrecognized family and generate silence?

Section 1

I think we want to say "by adding itesm with values 2 and 3" to the
registry, since we add two entries and not a single superposed entry.

Section 3.1

While I can deduce this from the list of allowed numbers of channels,
noting that both ends of the range (0 and 14) are allowed values probably
would add clarity.

Section 3.2

Figure 3 could perhaps make it more clear that C and K are not necessarily
equal.

The term "side information" is used without definition (and is not used in
RFC 7845).  Does this clause really add anything in comparison to if we
just say "The matrix MUST be provided in the channel mapping table portion
of the identification header, in place of a normal channel mapping table"?

Section 5.1

Family 255 is specified in Section 5.1.1.3 of RFC 7845, not 5.1.1.4.
(Also, the unqualified Section references should probably all be of the
form Section N of RFC 7845, for the benefift of the HTML linkification
tooling.)

Section 8

Sometimes I see a "Description" column that allows for in-registry
visibility that a range is for experimental usage.  I suppose it would not
be too hard to also modify the registry structure to add such a thing, if
you want.