It includes common methods used by Gnome Mplayer and Gecko Media Player. The library also contains several widgets that can be used by other applications. Those widgets are
gmtk_media_player - a widget that completely embeds Mplayer
gmtk_media_tracker - a widget that manages the timeline of media
gmtk_audio_meter - a audio visualization tool
gmtk_output_combobox - a widget for selecting audio outputs (alsa and pulse compatible)