Re: [media-types] Update to media type "application/ttml+xml"

Dear Philippe,

I could not find a complete information but it looks like TTML is a
format that could be contained in a clipboard. E.g. when transporting a
(piece of a) transcript from one document to another. Could I, thus,
suggest that you add below the Macintosh File type and such extra
information two fields:
- Windows clipboard flavour:
- MacOS uniform type identifier:
In order to find the right clipboard type names, a little bit of
research should be done on the existing practice.
Which tools exist out there which can accept or produce TTML?

thanks in advance.

Paul
> Philippe Le Hegaret <mailto:plh@w3.org>
> 16 June 2016 at 16:16
> The W3C Timed Text Working Group would like to update the media type
> "application/ttml+xml" as follows. Comments are welcome.
>
> It updates the media type, "application/ttml+xml" to add a new
> parameter, codecs. All other provisions of the media type
> specification remain the same. This supercedes the initial
> registration information in TTML 1.0 Second Edition.
>
> Text copied below but see also the original text at:
>  https://www.w3.org/TR/2016/NOTE-ttml-profile-registry-20160510/#mediatype
>
>
> [[
>
> Type name:
>
>     application
> Subtype name:
>
>     ttml+xml
> Required parameters:
>
>     None.
> Optional parameters:
>
>     charset
>
>         If specified, the charset parameter must match the XML
> encoding declaration, or if absent, the actual encoding. See also
> Encoding Considerations below.
>     profile
>
>         The document profile of a TTMLDocument Instance may be
> specified using an optional profile parameter, which, if specified,
> the value of which must adhere to the syntax and semantics of
> ttp:profile parameter defined by TTML 1.0 Second Edition, Section
> 6.2.8 ttp:profile of the published specification.
>
>     codecs
>
>         The optional codecs parameter provides a short form version of
> the profile parameter with multiple-profile combinatorial capability.
> If a short (4-character) form of a profile is registered in the TTML
> Profile Registry, it is recommended that this codecs parameter be used
> and not the profile parameter. The nominal value of this parameter is
> a single 4 character code from the registry.
>
>         Additionally, applications using the entries in the registry
> are encouraged to adopt the following combination syntax:
>
>         Employ two combination operators, '+' (AND) and '|' (OR),
> which may be used to specify, respectively, that multiple processor
> profiles apply (simultaneously) or that any processor profile of a
> list of profiles may apply individually. If both operators are used in
> a codecs value, then the '+' operator has precedence.
>
>         The example: "A+B|C+D|E" states that a TTML processor that
> implements any one of A+B or C+D or E processor profiles satisfies, at
> first order, the requirements to fetch and begin decode/processing of
> a TTML document, where X+Y means that both X and Y processor profiles
> must be supported, and X|Y means that either X or Y processor profile
> must be supported.
>
>         For more information about processor profile combination, see
> TTML2 Profile Combination.
>
> Encoding considerations:
>
>     Same for application/xml, except constrained to either UTF-8 or
> UTF-16. See IETF RFC 3023, XML Media Types, Section 3.2. For the
> purpose of filling out the IANA Application for Media Type
> (http://www.iana.org/cgi-bin/mediatypes.pl), the value binary applies.
> Security considerations:
>
>     As with other XML types and as noted in IETF RFC 3023, XML Media
> Types, Section 10, repeated expansion of maliciously constructed XML
> entities can be used to consume large amounts of memory, which may
> cause XML processors in constrained environments to fail.
>
>     In addition, because of the extensibility features for TTML and of
> XML in general, it is possible that "application/ttml+xml" may
> describe content that has security implications beyond those described
> here. However, TTML does not provide for any sort of active or
> executable content, and if the processor follows only the normative
> semantics of the published specification, this content will be outside
> TTML namespaces and may be ignored. Only in the case where the
> processor recognizes and processes the additional content, or where
> further processing of that content is dispatched to other processors,
> would security issues potentially arise. And in that case, they would
> fall outside the domain of this registration document.
>
>     Although not prohibited, there are no expectations that XML
> signatures or encryption would normally be employed.
> Interoperability considerations:
>
>     The published specification describes processing semantics that
> dictate behavior that must be followed when dealing with, among other
> things, unrecognized elements and attributes, both in TTML namespaces
> and in other namespaces.
>
>     Because TTML is extensible, conformant "application/ttml+xml"
> processors may expect (and enforce) that content received is
> well-formed XML, but it cannot be guaranteed that the content is valid
> to a particular DTD or Schema or that the processor will recognize all
> of the elements and attributes in the document.
> Published specification:
>
>     This media type registration is extracted from the TTML Profile
> Registry.
> Applications that use this media type:
>
>     TTML is used in the television industry for the purpose of
> authoring, transcoding and exchanging timed text information and for
> delivering captions, subtitles, and other metadata for television
> material repurposed for the Web or, more generally, the Internet.
>
>     There is partial and full support of TTML in components used by
> several Web browsers plugins, and in a number of caption authoring tools.
> Additional information:
>
>     Magic number(s):
>     File extension(s):
>
>         .ttml
>     Macintosh file type code(s):
>
>         "TTML"
>     Fragment identifiers:
>
>         For documents labeled as application/ttml+xml, the fragment
> identifier notation is intended to be used with xml:id attributes, as
> described in section 7.2.1 of the Timed Text Markup Language 1 (TTML1)
> specification.
>
> Person & email address to contact for further information:
>
>     Timed Text Working Group (public-tt@w3.org)
> Intended usage:
>
>     COMMON
> Restrictions on usage:
>
>     None
> Author:
>
>     The published specification is a work product of the World Wide
> Web Consortium's Timed Text (TT) Working Group.
> Change controller:
>
>     The W3C has change control over this specification.
> ]]
> https://www.w3.org/TR/2016/NOTE-ttml-profile-registry-20160510/#mediatype
>
> Thank you,
>
> Philippe
>
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