W3C home > Mailing lists > Public > public-tt@w3.org > May 2014

Re: Liaison response - template on MIME type parameter for TimedText

From: Nigel Megitt <nigel.megitt@bbc.co.uk>
Date: Wed, 14 May 2014 18:06:14 +0000
To: David Singer <singer@apple.com>
CC: Glenn Adams <glenn@skynav.com>, Cyril Concolato <cyril.concolato@telecom-paristech.fr>, TTWG <public-tt@w3.org>
Message-ID: <2112A03C-A1FF-4B6B-B869-7C32C76C4635@bbc.co.uk>
I don't believe that would help. The choice of interpretation as AND or OR depends on whether you're describing a document's conformance or a set of processors which could handle the document. The likelihood is that the parameter will be misinterpreted whichever we choose, and regardless of how clearly we specify the meaning. 

I suggest we use a symbol associated with neither AND not OR to highlight to anyone about to make an incorrect assumption that they should look up what it means and not just guess. 

Perhaps # would work as a two-way combinatorial operator?

So when used to express conformance with multiple specifications stpp.ttml.abc#def means "conforms to both/all" (the AND relationship) but when used to offer a choice of processors it means "any of these processors can handle" (the OR relationship). 

Any further decisions about the document or processing choice are delegated to the implementation and may require parsing a document. 

Nigel


On 14 May 2014, at 18:52, "David Singer" <singer@apple.com> wrote:

>> 
>> codecs=“stpp.ttml.st10+tt1p”
>> 
>> or something similar, expressing one TTML track for which either an st10 processor or a tt1p processor are acceptable.
>> 
>> ok; but does anyone but me wonder if '+' is the best operator? in my mind it is more associated with AND than OR; could we use '|' instead?
> 
> My read of the RFCs is that we need to avoid period, comma, and double-quote, so vertical bar should be fine.
> 
> 
> David Singer
> Manager, Software Standards, Apple Inc.
> 
> 


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Received on Wednesday, 14 May 2014 18:06:47 UTC

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