MediaConch / Media Info Tagging SMPTE-TT Files with IMSC

[joe-sciame-wm]

Hi Jerome,

What makes a TTML file labeled as a specific Format Profile? We have a TTML file that is coming out as:

Commercial name : TTML
Format profile : SMPTE-TT / EBU-TT / IMSC1

We can see from the header that the xml namespaces have all 3, but only two are used in any of the remaining tags.

<tt xmlns="http://www.w3.org/ns/ttml" xmlns:ttm="http://www.w3.org/ns/ttml#metadata" xmlns:tts="http://www.w3.org/ns/ttml#styling" xmlns:ttp="http://www.w3.org/ns/ttml#parameter" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns:smpte="http://smpte-ra.org/schemas/2052-1/2013/smpte-tt" xmlns:xml="http://www.w3.org/XML/1998/namespace" xmlns:ebutts="urn:ebu:tt:style" xmlns:itts="http://www.w3.org/ns/ttml/profile/imsc1#styling" ttp:timeBase="media" ttp:frameRate="25" ttp:frameRateMultiplier="1 1" ttp:cellResolution="32 15" xml:lang="sv-SE" xml:space="preserve">

I can send you the file offline if you would like to review it, but I would only expect it flagged if it used. I'd also think that the format can be only one but which one is the question I'd need to figure out.

[JeromeMartinez]

We can see from the header that the xml namespaces have all 3

And this is what we display, we display what the file claims it is.

but only two are used in any of the remaining tags.

My understanding is that if all elements / attributes are in the authorization list, it is compliant with this profile, even if no specific profile feature is used, so the claim from the file is not incorrect.

but I would only expect it flagged if it used

In my opinion a file flagged as IMSC1 compatible does not have to use any of the extra and specific IMSC1 elements, because a IMSC1 player will be able to play it.
You may want to know the lowest profile available, or if it is legitimate to flag it as IMSC1, in my opinion it could be a "conformance warning" (not error because the file is compliant) because the IMSC1 claim is useless and misleading.

This is currently not implemented, but could be.