PublicationEvent: playsOut MediaResource as well as (or: instead of) Essence

[wivaku]

The schema supports linking a specific Essence to a PublicationEvent:
ec:PublicationEvent ec:playsOut ec:Essence

Essence is a subclass of MediaResource.
It is not clear why it could link to only the subclass.

It would make sense to (also) linking the parent class:
ec:PublicationEvent ec:playsOut ec:MediaResource

Or in case backwards compatibility is desired:
ec:PublicationEvent ec:playsOutMediaResource ec:MediaResource

[RendersKoen]

Hi Winfred!

As I interpret it, because of the difference between

"a resource that comprises audio, video..." (MediaResource)
and
"a file or file package for play-out or publishing" (Essence)

A MediaResource can be something like an Essence Package (consisting of hi-res / lo-res / keyframes...). (as VRT has in our Avid Interplay MAM, or a mediaobject in NOA MediArc)

I personally think it's a good idea to keep the two separate. As soon as your resource is intended / suitable for playout as such, you should model it as Essence?

Although the entire Resource class and subclasses is not entirely clear for me as well. It would be nice to have an overview with examples and usecases.

Or maybe it's just a question of documentation

For example
ec:Component dcterms:description "A component e.g. audio, video, data or else or a MediaResource or Essence."
is not very clear :-)