Re: {minutes} TTWG Meeting 2015-12-17

Dear Glenn, all,

Am 17.12.2015 um 20:01 schrieb Glenn Adams:
>         atai2: For example, EBU-TT-D, which is a subset of IMSC, also
>         prohibits the ttp:element and the ttp:attribute. If they were
>         required in the
>         ... document then it would be impossible to make EBU-TT-D a
>         subset of IMSC, so EBU is fine with this.
> Our review of the EBU-TT-D specification indicates there is no such 
> prohibition specified.

I think with "review" you refer to an off list exchange about this 
topic. I can only confirm what I said in the meeting yesterday and also 
in that exchange: the EBU-TT-D spec was specified in a way to not allow 
any other TTML vocabulary in a EBU-TT-D instance than explicitly  
specified. The ttp:profile element and the tt:profile element are not 
specified and therefore are also not allowed. The XML Schema for EBU-TT 
Part 1 or EBU-TT-D would give you a validation error if you would 
specify these or other vocabulary in an EBU-TT-D document.

In your reading there is no restriction on the EBU-TT-D document model 
on the authoring side and in consequence there would be no difference 
between TTML 1 and EBU-TT-D document. This is NOT the case. EBU-TT-D is 
vocabulary subset of TTML 1.

If you read it the other way than there is a misunderstanding and from 
EBU groups side we may have to see how we can avoid this kind of 
misreading of the spec in future publications.

Best regards,


Andreas Tai
Production Systems Television IRT - Institut fuer Rundfunktechnik GmbH
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Received on Friday, 18 December 2015 13:24:57 UTC