Just to be sure I made no mistake here, I tested in dolphin with a ogg,
ogv, webm and mp3 file, and sure enough, dragonplayer do not show in the
GUI as an alternative for playing these files.
The lacking mime types in the dragonplayer desktop file is a usability
problem for anyone trying to use dragonplayer as their primary video
player on the Linux desktop.
At the very least, please add audio/ogg, video/ogg, video/webm and
audio/mpeg (the ones outputed by 'file --mime-type' for the files) to
the desktop file, to ensure these Linux wise commonly used audio and
video formats are recognized.