[Mlcodec] Re: Last call for Opus Extension

[Roman Shpount <[e-mail]>]

On Fri, Aug 8, 2025 at 1:31 PM Timothy B. Terriberry <[e-mail]>
wrote:

> Roman Shpount wrote:
> > In section 3. IANA Considerations: a new registry is defined. It would
> > be helpful to provide the IANA registration template.
>
> Is that not covered by the table that follows? Or is there something
> else IANA wants to see here?
>

I cannot speak for what IANA wants to see there, but adding a language like
this will make it easier for future experts to review new additions to the
registry:

* *Registry name:* “Opus Extension IDs” (under new “Opus” group)
** Value:* 0–127 (7-bit)
** Registration policy: "*Standard Action"
** Registration template MUST include:* ID, short name, L-flag behavior,
allowed multiplicity, extension interaction notes, any media type
parameters, and security considerations reference.

Additionally, in Section 3.1.

1. It would be helpful to include ABNF in the optional parameter
definitions.

EXTENSION_ID =  1*3DIGIT
EXTENSION_LIST = EXTENSION_ID *(COMMA EXTENSION_ID)
extensions=EXTENSION_LIST
sprop-extensions=EXTENSION_LIST
ext-param = "ext"  EXTENSION_ID "-" 1*(ALPHA / DIGIT / "-")
sprop-ext-param = "sprop-ext" EXTENSION_ID "-" 1*(ALPHA / DIGIT / "-")

This avoids questions, such as whether white space is allowed in
the extensions and sprop-extensions lists between the extension IDs and
commas.

2. Should extension lists be sorted or deduped?
3. It should explicitly state that N is the decimal extensions ID with no
leading zeros
4. Should state that unknown extN-* and sprop-extN-* params MUST be ignored
unless the corresponding extension ID is present/negotiated

Best regards,
_____________
Roman Shpount