If many of you are finding .ass files won't work in Avidemux, or other movie encoder applications, then here's a trick to get those .ass files into .srt files so that Avidemux is happy.
-Install MPlayer (required by KSubtitle)
-Using KSubtitle, follow the instructions in the HELP->KSubtitle_Handbook for importing a subtitle file.
-Using FILE->IMPORT, load the subtitle file [filename].ass
-Note: you may get a dialog box (some subtitles from .ass files may have overlapping timecodes). You have the choice to ignore the overlapping subtitles, or include them with their timing altered. If the added subtitles are comments from subtitlers, you may consider removing them. I did not ... so far.
-Load the movie file associated with the .ass file (if [filename].ass subtitle is for [filename].mkv, then select the moviefile [filename].mkv. This will give Ksubtitle the data to link the srt subtitle conversion to (timecodes?).
-Note: when opening a movie file, KSubtitle lists only mpg in filter. It seems that when I set the filter to 'All files', and loaded an mkv, it played just fine.
-movie file will load.
-Preview the movie file with KSubtitle's built in movie player (it's MPlayer and that's why you have to install it), just to make sure you loaded the right movie.
Goto FILE->Save_As and input name for the srt file
KSubtitle will then transcode the [filename].ass file to [filename].srt
THEN Avidemux is happy...