Add some pre-existing scripts.

sub_extract_convert

@@ -0,0 +1,24 @@
+#!/usr/bin/env bash
+# usage: $scriptname $files $output_sub_format
+output_sub_format=${@: -1}
+for i in $@
+do
+  if [ ! -e "$i" ];
+  then
+  	echo "File does not exist."
+  	continue
+  fi
+  index=$(ffprobe -v 8 -show_streams -select_streams s "$i" | grep index | cut --delimiter="=" -f 2)
+  if [ -z $index ];
+  then
+  	echo "No subtitle streams found."
+  	exit
+  fi
+  ffprobe -v 8 -show_streams -select_streams "$i"
+  filename=${i%.*}
+  mkvextract "$i" tracks $index:"${filename}.en.ass"
+  if [ ! -z $1 ];
+  then
+  	subtitleedit /convert "${filename}.en.ass" $output_sub_format 2>/dev/null | grep --color=none ass
+  fi
+done