Segue dica para este excelente programa funcionar perfeitamente. Ele não permitia inserir a legenda no filme. Basta editar o arquivo.
You must edit /usr/bin/xdvdshrink.pl to enable subtitles:
1)sudo gedit /usr/bin/xdvdshrink.pl
2) Go to line 969 and change
if ( qx/subtitle2pgm -h 2>&1/ !~ /-X/ ) {
to this
if ( qx/subtitle2pgm -h 2>&1/ !~ // ) {
I had the same problem and this was the only solution I found.
Fonte:
http://ubuntuforums.org/showthread.php?t=490392