EBU-TT to DXFP - Githubissues

IRT-Open-Source / scf

Subtitling Conversion Framework

Apache License 2.0

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EBU-TT to DXFP #7

Closed ggodart closed 8 years ago

ggodart commented 9 years ago

It would be useful for an XSLT translation for EBU-TT to DXFP for deployments wishing to use Microsoft Smooth streaming of subtitles. We believe this would be a pretty simple edit of the EBU-TT to EBU-T-D template to exchange the namespaces of EBU-TT-D and take out few extensions.

nigelmegitt commented 9 years ago

If the Smooth player is TTML compliant then it should play EBU-TT and EBU-TT-D already. (DFXP is a TTML profile, and EBU-TT is based on it already) Can you describe any further constraints of the Smooth player to permit playback of DFXP format subtitles? What happens if you provide an EBU-TT file to a Smooth player now?

ggodart commented 9 years ago

I'm not able to do this at the moment (I don't have any streams) has anyone else tried it?

nigelmegitt commented 9 years ago

I haven't tried it, but I'm puzzled: why don't you think it works already?

andreastai commented 9 years ago

We certainly are planning to provide a module that converts EBU-TT (and possibly any TTML document) into a DFXP file.

What I think is necessary:

Replace the TTML 1.0 namespaces with the DFXP namespace (e.g. http://www.w3.org/2006/10/ttaf1 with http://www.w3.org/ns/ttml
Check if there are any changes from DFXP (http://www.w3.org/TR/2009/CR-ttaf1-dfxp-20090924/) to TTML 1. I think there are some small changes but nothing serious.
Take out any vocabulary not in TTML namespace. This should not be problem from the spec but I expect that some players will have problems with this.

ggodart commented 9 years ago

In answer to Nigel - Murphy's law :-)

nigelmegitt commented 9 years ago

I think I see... There's a version issue here. DFXP is formally defined in the W3C Recommendation for TTML1 at http://www.w3.org/TR/ttml1/#profile-dfxp-full - I think you're talking about creating a version of the EBU-TT or EBU-TT-D or TTML file that's compatible with implementations of the earlier Candidate Recommendation format. characterised by the ...2006/10/ttaf1 namespace. Has the Smooth implementation not been updated to meet the Recommendation?

ggodart commented 9 years ago

I was originally asked what subtitle format MSFT Smooth stream supported. This led me to here; http://docs.unified-streaming.com/documentation/package/subtitles/subtitles-captions.html Which described DFXP.

nigelmegitt commented 9 years ago

Okay... that refers to DFXP/TTML so I would assume in the absence of other information that it means TTML1 or even TTML1SE, i.e. the Recommendation version. It doesn't mention namespaces. The only oddity is that it wants a .dfxp extension when the registered extension is .ttml

andreastai commented 8 years ago

One TTML2DFXP module is provided with commit ea409d078ff322c7206700baa341ac4db81fee69. This module could also be used to solve the use case by @ggodart (convert EBU-TT to DFXP).