Re: [codec] draft-ietf-codec-oggopus: attached pictures

[Mark Harris <[e-mail]>]

Ron wrote:
> On Fri, Aug 29, 2014 at 10:38:14PM -0700, Mark Harris wrote:
>> If this is not addressed prior to the standard being finalized, it
>> becomes very difficult to add later.
>
> I don't see why you think this is so?  Ogg was designed from the outset
> to be easily extensible to carry and multiplex any sort of data.

Yes, arbitrary binary data is allowed by Ogg, and none of my proposals
involved changes to Ogg.  This is about Ogg Opus files as defined by
the draft draft-ietf-codec-oggopus-04.  The current version of the
draft does include some binary metadata within an Ogg Opus stream,
such as channel mappings, but does not provide any mechanism for
adding additional metadata to the Ogg Opus stream in a binary format.
Furthermore the current draft does not permit an Ogg Opus file to
contain any other multiplexed streams (section 10).

> What are we missing that makes that impossible?

If the draft included a way to add arbitrary binary metadata to the
Ogg Opus stream, or allowed an Ogg Opus file to contain attached
pictures that are stored in another multiplexed stream, then the
details of the picture format could be specified outside of this
specification.

 - Mark