Removed 2119 language for general Ogg requirements.
Added IANA registry for channel mapping families.
Adjusted additional copyright grant to match RFC 6716.
Additional comments addressed (see the CODEC mailing list).

Mark Harris convinced me that the significant delay between "WG
 consensus" and "RFC" means we shouldn't rely on RFC updates to
 give people permission to start deploying new things.

Thanks to Mark Harris for the report.

Also remove most <preamble>/<postamble> usage for expository text,
 as most places center the result, which looks ugly (only local
 xml2rfc HTML output does not center: tools.ietf.org HTML output
 still does, as does the .txt version).

To avoid confusion with an RFC 6716 encoder/decoder.
No part of this document is intended to update RFC 6716.

I *think* all we need to do is document this and the RFC editors
will take care of it.

We mention this in the description of Channel Mapping Family 0.
Might as well link to RFC 7587.

Review comment from Mo Zanaty.

This improves readability in the xml2rfc html output, but
generates Markdown-style *bold* in the txt output, and
more importantly in the nroff-like html output of the
tools.ietf.org toolchain, which Mo Zanaty and some in
IRC objected to.

Based on Mo Zanaty's review comments.

Response to comments from Mo Zanaty. Using "muxer/demuxer"
really isn't less ambiguous than "encoder/decoder" but does
help distinguish between this draft and a 'codec encoder/decoder'
described by the Opus RFC.

Mark Harris authored 9 years ago and Jean-Marc Valin committed 9 years ago

Signed-off-by: Jean-Marc Valin <jmvalin@jmvalin.ca>

This version resolves some issues with the packet size limits
 raised by Mark Harris.

1. Removed an inappropriate normative MAY.
2. Gave an explicit range of sample rates deemed to be "non-crazy".
3. Give explicit guidance on packet sizes that SHOULD and MAY be rejected.

This is just a should, so we want to leave the RFC 6716 reference
to the second occurance, but using the same language ties them
together and to the later occurances.

The Opus RFC doesn't really say what to do beyond rejecting
a particular packet, but having the reference reinforces that
we're trying to leverage the same constraints in the specific
context of ogg encapsulation, and this isn't a new rule.

Suggestion from mark4o.

This avoids confusion with the number of frames being defined
by more than the first byte with code 3 packets.

Patch from mark4o.

The macros take arguments, they aren't just constants. Thanks to
mark4o for the report.

Add a limit of no more than 6 characters for these tags' values.

Based on http://vfrmaniac.fushizen.eu/contents/opus_in_isobmff.html