Re: [clue] MaxCaptures updated text

Hi Christian,
This makes sense to me.

If anybody still wants to propose text for adding the "switched" attribute, please do so.  But I think we don't need it.

More Comments inline.
Mark

> -----Original Message-----
> From: clue [mailto:clue-bounces@ietf.org] On Behalf Of Christian Groves
> Sent: Wednesday, March 05, 2014 7:42 PM
> To: clue@ietf.org
> Subject: [clue] MaxCaptures updated text
> 
> Hello all,
> 
> Here's some proposed text to address today's action point on MaxCaptures
> with respect to "=" and "<=". Its also partly also addressing the discussion we
> had on "switched" and "composed" by listing the interaction between the
> MaxCaptures value and the number of captures in the MCC. Hopefully that
> gives a framework for further discussions.
> 
> 
> 7.2.1.1. Maximum Number of Captures within a MCC
> 
> The Maximum Number of Captures MCC attribute indicates the maximum
> number of individual captures that may appear in a Capture Encoding at a
> time. It may be used to derive how the Single Media Captures within the
> MCC are composed / switched with regards to space and time.
> 
> <<<A Provider can indicate that the number of captures in a MCC capture
> encoding is equal "=" to the MaxCaptures value or that there may be any
> number of captures up to and including "<=" the MaxCaptures value. This
> allows a Provider to distinguish between a MCC that purely represents a
> composition of sources versus a MCC that represents switched or switched
> and composed sources.>>>
> 
> Max Captures MAY be set to one so that only content related to one of the
> sources are shown in the MCC Capture Encoding at a time or it may be set to
> any value up to the total number of Source Media Captures in the MCC.
> 
> <<<The bullets below describe how the setting of MaxCapture versus the
> number of captures in the MCC affects how sources appear in a capture
> encoding:
> 
> o When MaxCaptures is set to <= 1 and the number of captures in the MCC is
> greater than 1 in the MCC this is a switched case. Zero or 1 capture may be
> switched into the capture encoding. Note: zero is allowed because of the
> "<=".
> 
> o When MaxCaptures is set to = 1 and the number of captures in the MCC is
> greater than 1 in the MCC this is a switched case. Only one capture source is
> contained in a capture encoding at a time.

[Duckworth, Mark] I suggest modifying these first two bullets:
o When MaxCaptures is set to <= 1 and the number of captures in the MCC is greater than 1 (or not specified) this is a switched case. Zero or 1 capture may be switched into the capture encoding. Note: zero is allowed because of the "<=".

o When MaxCaptures is set to = 1 and the number of captures in the MCC is greater than 1 (or not specified) this is a switched case. Only one capture source is contained in a capture encoding at a time.

> o When MaxCaptures is set to <= 2 and the number of captures in the MCC is
> greater than 2 this is a switched and composed case. The capture encoding
> may contain purely switched sources (i.e. <=2 allows for 1 source on its own),
> or may contain composed and switched sources (i.e. a composition of 2
> sources switched between the sources).
>
> o When MaxCaptures is set to = 2 and the number of captures in the MCC is
> greater than 2 this is a switched and composed case. The capture encoding
> contains composed and switched sources (i.e. a composition of 2 sources
> switched between the sources). It is not possible to have a single source.

[Duckworth, Mark] It sounds like these two paragraphs above apply not only for the value 2, but more generally to any value >=2.  Is that your intent?

Also I suggest including in the above two bullets the case where the number of captures in the MCC is not specified.  Or we could write it as separate bullets like this:

o When MaxCaptures is set to <= 2 (or any number greater than 2) and the number of captures in the MCC is not specified this is a switched and composed case. The capture encoding may contain purely switched sources (i.e. <=2 allows for 1 source on its own), or may contain composed and switched sources (i.e. a composition of 2 sources switched between the sources).

o When MaxCaptures is set to = 2 (or any number greater than 2) and the number of captures in the MCC is not specified this is a composed case, and may also be switched.

> o When MaxCaptures is set to <= to the number of captures in the MCC this
> is a switched and composed case. The capture encoding may contain media
> switched between any number (up to the MaxCaptures) of composed
> sources.
> 
> o When MaxCaptures is set to = to the number of captures in the MCC this is
> a composed case. All the sources are composed into a single capture
> encoding.>>>
> 
> If this attribute is not set then as default it is assumed that all source content
> can appear concurrently in the Capture Encoding associated with the MCC.
> 
> ...
> 
> In section 10:
> 
> - The Consumer may or may not choose to receive all the indicated captures.
> Therefore it can choose to receive a sub-set ofCaptures indicated by the
> MCC. <<<Where a MCC indicates that the MaxCaptures is equal to a
> particular number of captures and the Consumer wishes to select a sub-set
> of captures, the number of captures it selects should at minimum be equal to
> MaxCaptures value.>>>
> 
> 
> Christian
> 
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