You should be fine. The mint-meta-codecs
package is usually listed as an umbrella package
that lists other packages that are needed.
If one actually opens the file they would find the following: Two directory's, changelog, compat, control, copyright, and rules files.
You can also download Opera directly from their site, un-tar the "tar.bz2" package and run Opera locally without installing it, similar with the way things are done with Firefox. A global install is also a possibility as well. In case you are unfamiliar with what I am referring to I will post a link that may help to inform you. http://www.opera.com/support/kb/view/456/
Hope this helps.