That is correct, both BIRT & Jasper reports are supported in Yellowfin.
It's worth noting that Yellowfin simply gets the report definition from an Existing Birt/Jasper report and imports it into yellowfin for use. Yellowfin cannot be used to create a Jasper/Birt report from scratch. Birt/Jasper reports do not use Yellowfin views as they connect directly to the database.
More information on this can be found via the links below:
Additionally, I would suggest using Yellowfin to create your reports (if possible) as this will allow you to fully modify the report. E.g. You can remove columns, modify the view that it is based on etc.