Subject: [clue] CLUE media capture description

From: Christian Groves <[email-masked]>
Date: Thu, 01 Nov 2012 13:31:17 +1100

CLUE media capture description
draft-groves-clue-capture-attr-00

I won't be attending the IETF next week so as a pre-cursor to next weeks 
CLUE WG meeting  I thought i'd put a few words together about 
draft-groves-clue-capture-attr-0
http://datatracker.ietf.org/doc/draft-groves-clue-capture-attr/

The main idea behind the draft is that a CLUE advertisement should 
include enough information for the receiver to make an educated decision 
about what captures it chooses. Having a had a close look at the content 
attribute I think (for the reasons outlined in the draft) it is 
insufficient to fully describe the multi-stream conferencing 
environments that CLUE is addressing/enabling.

A contribution with essentially the same text as the draft was submitted 
to the recent Q.5/16 meeting to solicit feedback from the people at the 
meeting about the different parameters presented in the draft. In 
general I think people were in agreement that the current Content 
attribute was not sufficient. However it was noted that it needs to be 
considered how CLUE maps to the existing usages of the content attribute 
and mapping to H.239.

Below is a list of attributes and comments. If I've left out anything or 
mispoken hopefully Steve Botzko can correct me.

Presentation
------------
People thought it was worthwhile to know if a capture related to a 
presentation. There was some questioning if it was worthwhile to know if 
the capture was slides, images etc. It was thought it may help where 
multiple presentation streams were used.

View
----
It was clarified that the aim of the attribute is to allow a remote end 
to make an automatic decision on what region of the scene it wants to 
see. The idea is that there is a standard keyword that the remote end 
could scan for e.g. lectern. This is a way of providing meaning to a 
particular spatial area.

Language
--------
There seemed to be general support for a language parameter.

Role
----
It was thought that role could be related to "participants" or 
"material". Currently the attribute only discusses role from the aspect 
of a participant. It was also noted that the role may change based on 
meeting type. For example: in the medical use case there could be 
"Surgeon", "Professor", in an accessible conference there could be an 
"Interpreter" or "signer". With respect to Materials it was thought 
presentation could show something like "Agenda", "Contribution".

Priority
--------
There was some discussion as to whether this was needed. It was thought 
that if captures were properly described then priority wouldn't be 
needed as the remote end could make an educated decision about what it 
wants. At the moment with the minimal set of attributes it was thought 
that priority at least helped the remote end make a decision.

Dynamic
-------
I think people were OK with this being optional.

Embedded Text
-------------
Again I think people thought it was reasonable. It was clarified this 
could also be used to indicate captioning was being used with the capture.

Supplementary description
-------------------------
There was some question about how this related to side bar conferences. 
It was clarified this was mainly about the case where information 
(captures) were provided by people (or devices) who were not captured by 
the conference video.

Telepresence
------------
This parameter probably had the least support/understanding. I was noted 
that CLUE was to allow multi-stream operation it didn't necessarily 
indicate/mandate a telepresence experience.

Hopefully this provides some further background for the CLUE 
discussions. If the group could come to some general agreement about 
each of the parameters then I could work on some specific text for the 
framework (or whatever document we decide).

Regards, Christian