I’m no gnome user but looking at that ymp it should be installing xine - A Free Video Player - Features which is libxine1 on Suse it is xine-lib iirc.
Really unsure why it is not installing libxine1 should be, I take it you’ve changed the engine. XINE - openSUSE this confirms the naming difference, check in software management.
As for codecs shouldn’t really need it going on this xine - A Free Video Player - About xine seems it is using some bits of ffmpeg .
Need MC here to tell you I know a few projects use ffmpeg some better than others, iirc both vlc and mplayer tweak ffmpeg.