====== ffmpeg - Subtitles - Add subtitles to MP4 vs MKV ======

<WRAP alert>
Different **syntax** is used for MP4 vs MKV.

  * In both cases you must specify video and audio codec, or just copy stream if you just want to add subtitle.

</WRAP>

----

===== MP4 =====

<code bash>
ffmpeg -i input.mp4 -f srt -i input.srt \
-map 0:0 -map 0:1 -map 1:0 -c:v copy -c:a copy \
-c:s mov_text output.mp4
</code>

<WRAP info>
**NOTE:**  Notice the **-c:s mov_text**.
</WRAP>

----

===== MKV =====

<code bash>
ffmpeg -i input.mp4 -f srt -i input.srt \
-map 0:0 -map 0:1 -map 1:0 -c:v copy -c:a copy \
-c:s srt output.mkv
</code>

<WRAP info>
**NOTE:**  Notice the **-c:s srt**.
</WRAP>


----

<WRAP info>
**NOTE:**  If mapping is not used, then adding additional subtitles would overwrite the existing ones.

To add language metadata (insert before output file) "-metadata:s:s:0 language=eng"

</WRAP>

----

<WRAP info>
**NOTE:**  .srt files must be imported with -c:s copy not with -c:s mov_text
</WRAP>

----

====== References ======

https://en.wikipedia.org/wiki/Comparison_of_video_container_formats