For all those people that have different metadata in calibre opposed to in the epub file itself.
There is a developer that created an OPDS reader that works with the Calibre Library
http://blog.slucas.fr/en/oss/calibre-opds-php-server.
In his latest update he created the option to send the latest metadata with the epub. Instead of converting your epub, it is now possible to get the latest metadata supplied when downloading the book to Marvin.
Marvin and Cops 0.3.4 integrate perfectly.
To use cops you will need (W)AMP running or some other web server. There is an install package for Synology.