Use FFmpeg to add subtitles to video

ffmpeg-add-subtitles.md

Use FFmpeg to add subtitles to video

MP4:

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

MKV:

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

To understand the -map option you'll first need to examine your source file by running the video trough ffprobe or ffmpeg

ffprobe video.mp4

OR

ffmpeg -i video.mp4

Then you'll see some lines named "Stream", each stream represent a video, sound and/or subtitle. Streams starting with 0: are video or sound tracks (streams) and streams starting with a number higher than 0 is subtitle (overlays)

To add several subtitles to the same video requires you to add a -c:s mov_text or -c:s srt for each subtitle submitted

If you like to add a title to each soundtrack or subtitle you can use the

-metadata:s: and -metadata:s:s

Example

For English soundtracks you'll use English for language

-metadata:s:0 language=English

For subtitle you have to use the extra s

-metadata:s:s:1 language=English \
-metadata:s:s:2 language=Dansk

I created an online tool which used this method to add subtitles to a video container, https://davidclews.com/article/280.html you can see the code in the browsers console

You should mention the rather small limitation, but good initiative.

This tool has a max filesize limit of 2.00 GiB or 2.15 GB

Thank you for this comprehensive documentation, much obliged!

… You've got a typo: It shouldn't say ffmprobe -i video.mp4 but ffprobe -i video.mp4.

Thanks @GerZah it's fixed, and glad you like my tiny guide on the topic,