Valid test resources:

• Have a <daptm:daptOriginTimecode> element present at the path /tt/head/metadata/daptm:daptOriginTimecode whose content conforms to a clock-time with a frames component, as defined in <time-expression> AND
• have a ttp:frameRate attribute on the root <tt> element with a valid value as per TTML2 (as per 5.7.3 ttp:frameRate)

Expect >=1 valid test resource.

Invalid test resources:

• Have two or more <daptm:daptOriginTimecode> elements present at the path /tt/head/metadata/daptm:daptOriginTimecode OR
• Have a <daptm:daptOriginTimecode> element present at the path /tt/head/metadata/daptm:daptOriginTimecode with content that does not conform to a clock-time with a frames component, as defined in <time-expression> OR
• Have a <daptm:daptOriginTimecode> element present at the path /tt/head/metadata/daptm:daptOriginTimecode whose content conforms to a clock-time with a frames component, as defined in <time-expression> BUT has no ttp:frameRate attribute on the root <tt> element OR
• Have a <daptm:daptOriginTimecode> element present at the path /tt/head/metadata/daptm:daptOriginTimecode whose content conforms to a clock-time with a frames component, as defined in <time-expression> and has a ttp:frameRate attribute on the root <tt> element BUT the frame component value >= the number of frames per second.

Expect >= 4 invalid test resources.

Presentation semantics

There are no presentation semantics associated with this feature.

Have two or more daptm:daptOriginTimecode elements present at the path /tt/head/metadata/daptm:daptOriginTimecode

Not sure we need to test that as this is basic XML rule.

Should we have an invalid test when the attribute is present on a metadata element somewhere else, like body?

Have two or more daptm:daptOriginTimecode elements present at the path /tt/head/metadata/daptm:daptOriginTimecode

Not sure we need to test that as this is basic XML rule.

I don't think it is, remember this is an element not an attribute.

Should we have an invalid test when the attribute is present on a metadata element somewhere else, like body?

(it's an element not an attribute)

It's not prohibited elsewhere, so it wouldn't be an invalid test, just a meaningless one.