Re: Formal Object to any new CR of IMSC1


I do not think this is a helpful move.

To recap the GitHub issue discussion:

Since IMSC defines two profiles of TTML the normative fallback defined in TTML1 applies in the absence of any other defined behaviour.

Furthermore the mechanisms for specifying either of the two profiles are coincident with the ttp:profile attribute as defined in TTML 1 and the presence  of ebuttm:conformsToStandard with the appropriate value for EBU-TT-D also indicates IMSC text profile conformance.

So this objection does not appear to be well formed, in that the assertion that no fallback behaviour is defined is false.

At the very least, IMSC is no worse than TTML1 in this respect, a topic which was much discussed at our recent face to face meeting.

Finally, it is clear that we do not have consensus for an IMSC specific algorithm, which by the way would further fragment the processing of generic TTML documents since any such processor would have to be configured somehow to expect one of either TTML or IMSC to know which rules to use. It is clear that IMSC is intended to be a profile of TTML and not a separate format in its own right.

I hope these arguments will persuade you to consider other options.

Kind regards


> On 11 Dec 2015, at 00:37, Glenn Adams <> wrote:
> Unless and until a fallback profile is mandated normatively in IMSC1, SKYNAV formally objects to any new CR being published.

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Received on Friday, 11 December 2015 09:52:09 UTC