Full Text for the media files

Hi,

We have a website using WordPress. We are looking at expanding our search engine. Currently the default search engine helps us to search the blogs and media files with the metadata called title and description attached to it. We want to convert the metadata search engine to full text search engine. This should scan and search all the file content and if the search keywords matches the text in the file it should display the link of the file.

Is there any widget or plug-in available for full text search for media files?

The site I am referring to is

http://www.evidencebased-management.com/

Thanks & Regards
Rupesh Mehta