In the early stages of Matterhorn, the approach to ingesting a mediapackge used 
to be that everything that is part of the mediapackage will be sent to the 
capture agent through the iCalendar feed and the capture agent would compile 
the full mediapackage and ingest it. Next to the recorded media files, this 
namely includes the dublin core catalogs for episode and series.

With 1.3, this approach has changed to a different model. The reasoning behind 
the change was that we wanted to put as little of a burden on the capture agent 
implementations as possible. What happens now is that at scheduling time, a 
workflow is created, containing all of the catalogs. The workflow is sitting 
there waiting for the capture agent to ingest. Once the ingest happens, the 
mediapackages (the one that is part of the waiting workflow and the one 
ingested by the capture agent) are merged.

Unfortunately, an implementation error resulted in the series dublin core not 
being added to that waiting mediapackage (while the series id is still being 
set), so if the capture agent did not add this series catalog to the 
mediapackage, it would not be part of it. Up until now, this went by unnoticed, 
since the series logic is solely based on the mediapackage metadata, which did 
include the series id. Only if one was interested in other series metadata 
itmes would one need to get hold of the catalog itself.

As a conclusion, I am suggesting the following change of behaviour starting 
with 1.5, and would like to get feedback from capture agent manufacturers:

In the case where a recording is scheduled, the workflow should contain all 
metadata as catalogs (this means fixing the current implementation by adding a 
reference to the series catalog). Once ingest happens, the mediapackages are 
merged in such a way that items that exist in both the workflow mediapackage 
and the ingested mediapackage will be taken from the ingested mediapackage. 
Equality of mediapackage elements will be determined by element flavor.

As a consequence, implementors (including Opencast itself for the reference 
platform) do *not* need to and also should not send catalogs as long as they 
are not looking to overwrite what's on the server. Also note that this 
implementation allows for series or episode metadata to be changed on the 
capture device.

The corresponding ticket has been created as 
http://opencast.jira.com/browse/MH-8906.

Tobias
_______________________________________________
Matterhorn mailing list
[email protected]
http://lists.opencastproject.org/mailman/listinfo/matterhorn


To unsubscribe please email
[email protected]
_______________________________________________

Reply via email to