After some more modifications on the "official" mediainfo gui (Maemo compiled version was posted here: http://talk.maemo.org/showthread.php?t=79959), I came to the conclusion it would be easier to start from scratch, going back to the KISS principle

In this case I use the CLI version of mediainfo (which I also uploaded to the extras-devel repo as dependency) for retrieving the media information, while the official gui includes the media-libraries itself.

mediainfo
mediainfo supplies technical and tag information for video, image or audio files.

Source can be found here: http://mediainfo.sourceforge.net/en/Download/Source, mediainfo is also available in the repos.
Changelog: http://mediainfo.sourceforge.net/Log

It supports a huge amount of formats, and it can extract basic or very detailed information.

mediainfo-gui
Mediainfo-gui offers the option to select known files and display its media info details. It has the option to set even more detailed info.
It can be found in the extras-devel repository.

Change history:

Code:

0.0.1-1
* Initial release
0.0.1-2
* Added bugtracker
* Fix small issue in initial path
0.0.1-3
* Sort files in browser case-insensitive
* Added some specific folder icons in browser
* Resize browser when switching from landscape to portrait

A Sailfish version can be found on openrepos.net