Note: You can propose changes using the forum below.
Gnome Subtitles is one of the most used video subtitling applications for the Gnome desktop, and Linux in general. Many users have requested the possibility to hardcode subtitles into the video files, directly from the application, as some devices don't support subtitles as text files.
The idea here is not to reinvent the wheel. Some applications exist that allow to join videos with subtitles, for example Mencoder and Avidemux. The idea is to simplify this process and integrate it with Gnome Subtitles, hopefully using the existing applications if possible.
The major requirement to start with is, therefore, to have a simple process for hardcoding subtitles into videos (perhaps with a wizard), directly from Gnome Subtitles, possibly using other applications.
Related bug in the Gnome Bugzilla: #484055 Allow to hardcode subtitles into a video (http://bugzilla.gnome.org/show_bug.cgi?id=484055).