[MPEG-OTSPEC] Note on VARC conditions and condition set negation

[Skef Iterum]

I guess I can answer my own question here: You have your current
proposal document and we have newfeatvar_spec.pdf. If you want to
propose this change for the April working group meeting /cleanly/ you can
do that by making an /additional/ proposal /against/ those two documents,
and emailing it here first. (newfeatvar_spec has all of the relevant VARC
content because of the editorial direction I took with it.)

That would presumably propose to:

 1. Eliminate condition formats 2 and 4 from newfeatvar_spec.
 2. Change format 3 back to 2.
 3. Add the three additional formats.
 4. Note in the condition set section that that mechanism has been
    partially superseded
 5. Make the appropriate changes to 6.2.10.

This way the alternate system is genuinely severable from the
content that has already been discussed and approved as part of the
Ad Hoc process.

I've already indicated what some of the 6.2.10 changes would be,
but they are:

 1. The LookupCondition record now just has a conditionOffset and a
    lookupIndexListOffset, from which lookups are taken when the
    (now potentially compound) condition at that offset is true.
 2. Assuming we're eliminating the condition set, you'll need to note
    somewhere appropriate that a 0 offset to a condition means the
    condition is true (as is true of condition sets).

I don't recommend getting rid of the conditionSet in the 
FeatureVariationRecord
because of the versioning issues that would introduce.

This still raises a lot of questions about lack of input and very short 
engineering
time, but it means that people could take it or leave it at the meeting 
on its
merits, rather than feeling pressured by it's sudden inclusion in a document
already tracked for approval.

Skef

On 4/11/24 16:09, Skef Iterum via mpeg-otspec wrote:
>
> The current newfeatvar_spec document has the negated conditions and 
> reorders the section on condition sets and conditions. This sort of 
> addition would need coordination between the two documents. I'm on PTO 
> Friday through Monday. How is this going to happen before the 17th?
>
>
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