+ const frameoffset_t vstart = ARDOUR_UI::instance()->video_timeline->get_offset();
+ const frameoffset_t vend = vstart + ARDOUR_UI::instance()->video_timeline->get_duration();
+
+ if ( (start >= end) || (end < vstart) || (start > vend)) {
+ warning << _("Export Video: export-range does not include video.") << endmsg;
+ Gtk::Dialog::response(RESPONSE_CANCEL);
+ return;
+ }
+