+ try_opt("-ss", self.opts.startpos)
+ try_opt("-endpos", self.opts.endpos)
+ try_opt("-dvd-device", self.opts.dvd)
+ try_opt("-chapter", self.opts.chapter)
+ try_opt("-aid", self.opts.audioid)
+ try_opt("-sid", self.opts.subtitleid)
+ try_opt("-vf-add", self.opts.vfilters)
+ try_opt("-af", self.opts.afilters)
+
+ def subst_values(self, cmd, vpass):