Documentation for media.delete() is available here:
It’s really a rather simple action that accepts one param: the entry ID you wish to delete. The entry will then be marked as deleted [entry.status =3] in the DB. Note however, that it will NOT remove the media files associated with this entry from storage. If you wish for these to be automatically removed [due to space considerations], see Validate the content off the database and the content of the folder /opt/kaltura/web/content/
As for deleting entries based on the userId, you can use media.list() and pass a
KalturaMediaEntryFilter object where the
userIdEqual member is set to ID in question. This will return a list of entry objects and you can then pass the entries ID to media.delete().
Documentation for media.list() is available here: