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In TTML1, <style> cannot contain <metadata>, but the EBU-TT-D XSD allows it:

The way that EBU-TT metadata is handled at the moment has some issues:

1. It enforces the ordering requirement from EBU-TT Part 1 v1
2. It may need updating to match EBU-TT Metadata Tech3390.

I suggest we remove the metadata from the EBU-TT-D XSD and create a new XSD for EBU-TT Metadata specifically.

The following change needs to be reflected in the EBU-TT-D XSD for version 1.0.1.

CHANGE: ittp:activeArea

Before

This feature and attribute was not present.

After

The attribute was added to the tt:tt element.

Found during the live toolkit implementation:

[0]*[1-9][0-9]*\s[0]*[1-9][0-9]*

Seems to be a better representation

For each merge request there is a review time for 10 working days (working days: Mo-Fr). If there no blocking comment it can be merged. Otherwise it needs to be resolved. If for some reason a resolution of a blocking comment is not feasible, a decision is made by the EBU Timed Text working group.

The maxOccurs attribute is omitted from the definition of ebuttm:documentIntendedTargetFormat, and it defaults to 1, so if a document wants to signal intended conformance to multiple target formats, this is prohibited. Suggest adding maxOccurs="unbounded".

The following change needs to be reflecred in the EBU-TT-D XSD for version 1.0.1

CHANGE: Attributes from the TTML metadata namespace

Before

The TTML 1 metadata attributes ttm:agent and ttm:role were allowed on tt:body, tt:p and tt:span.

After

TTML 1 metadata attributes can be used as defined in TTML 1.

The following change needs to be reflected in the EBU-TT-D-XSD

CHANGE: Attribute itts:fillLineGap

Before

This feature and attribute was not present.

After

The attributes was added to the tt:style element.

When validating ebutt_d.xsd using Oxygen the following error is given:

The namespace attribute, 'http://www.w3.org/ns/ttml#styling', of an element information item must be identical to the targetNamespace attribute, 'urn:ebu:tt:style', of the imported document.

Changing line 8 to <xs:import namespace="urn:ebu:tt:style" schemaLocation="styling.xsd"/> solved the issue but I would like confirmation that this is the correct solution.

The URI for the schema location of the xml.xsd in ebutt_d.xsd has a leading space. Although the data type of the schema location attribute is xs:anyUri and spaces are allowed for that type, their use is discouraged and may also result in problems for schema validating processors.

See also ebu/ebu-tt-m-xsd#30.

A note should say, that all document vocabulary that is not defined in TTML1 or EBU-TT-D needs to be pruned before validation. Otherwise the new XSD may generate "false negative" i.e. it could produce an error for a document that conforms to TTML1.

ebutt_d.xsd specifies http://www.w3.org/ns/ttml as the target namespace, conflicting with the TTML1 XSD -- specifically ttaf1-dfxp-document.xsd, which also defines the same target namespace.

The distributionMediaTimingType currently does not allow the specification of fractions of a second with less than three digits (e.g. 00:00:00.12 would not be allowed). But the EBU-TT-D spec does not specify this restriction.