Re: Time expressions when ttp:timeBase="media"

This should be resolved in the current ED, in Appendix N.2 [1]. Please
check and verify.

[1]
https://dvcs.w3.org/hg/ttml/raw-file/default/ttml10/spec/ttaf1-dfxp.html#time-expression-semantics-media


On Wed, Feb 13, 2013 at 8:21 AM, Glenn Adams <glenn@skynav.com> wrote:

>
> On Wed, Jan 30, 2013 at 10:38 AM, Jason Livingston <jason@cpcweb.com>wrote:
>
>>  I still have a question about the starting time of the media object
>> though.  Does the media object time always start at 0 seconds, or can "a
>> coordinate in the media object's time line" be interpreted to mean that the
>> media object could start at a non-zero time?  (E.g. if the media object has
>> a time code track which starts at 01:00:00:00)
>>
>> ** **
>>
>> Personally I would like the answer to be "the media object always starts
>> at 0 seconds," but I am not certain if that's the only possible
>> interpretation of the spec.
>>
>
> The TTML media timebase value of zero corresponds to the beginning of the
> external time interval. If the external time interval is derived from a
> related media object, then that beginning is implied from the beginning of
> that related media object.
>
> I agree that this could be made more clear in the spec, so I've filled
> https://www.w3.org/AudioVideo/TT/tracker/issues/200 to that effect
>