add another example

Automation-examples.md

@@ -162,4 +162,36 @@ for FILE in *.mkv *.webm ; do
 done
 ```
 
+## Example 4: combine MP4 files with similarly named subtitle files
+
+Often you might have a lot of MP4 files lying around with subtitle files that are similarly named: only the extension differs
+(e.g. `Wonderful Movie.mp4` and `Wonderful Movie.srt`). The following example iterates over all MP4 files in the current directory. It looks
+for SRT and VobSub subtitle files in the same directory that have the same base name (both are used if both are found). Then it multiplexes
+all of them together into a Matroska file.
+
+This example is written in shell (`bash` or `zsh`) and doesn't have any other requirements.
+
+```sh
+# an array for the arguments
+declare -a args
+
+# loop over all MP4 files
+for mp4 in *.mp4 ; do
+  base="${mp4%mp4}"
+  args=(-o "output/${base}mkv" "${mp4}")
+
+  # look for subtitles with the same base name
+  if [[ -f "${base}srt" ]]; then
+    args=("${args[@]}" "${base}srt")
+  fi
+
+  if [[ -f "${base}idx" ]]; then
+    args=("${args[@]}" "${base}idx")
+  fi
+
+  # create output file
+  mkvmerge "${args[@]}"
+done
+```
+
 Categories: [merging](FAQ#category-merging), [misc](FAQ#category-misc)