![](https://reddthat.com/pictrs/image/3f822785-3ddc-4a5f-8413-594a9b2812f2.png)
![](https://lemmy.kde.social/pictrs/image/19e6d51f-5131-409e-8990-827d3d29e4d3.png)
I don’t know how to do it with KDE’s tools, but on the command line with ffmpeg you can do something like this:
ffmpeg -i video_track.mp4 -i audio_jp.m4a -i audio_en.m4a -map 0:v -map 1:a -map 2:a -metadata:s:a:0 language=jpn -metadata:s:a:1 language=eng -c:v copy -c:a copy output.mp4
Breaking it down, it:
- runs
ffmpeg
- with three inputs (
-i
flag) – a video file, and two audio files. - The streams are explicitly mapped into the result, counting the inputs from 0 – i.e.
-map 0:v
maps input 0 (the first file) as video (v
) to the output file and-map 1:a
maps the next input as audio (a
), etc. - It sets the metadata for the audio tracks
-metadata:s:a:0 language=jpn
sets the first audio track (again counting from 0…) to Japanese; the second metadata option sets the next audio track to English. -c:v copy
specifies that the video codec should be copied directly (i.e. don’t re-encode – remove this if you DO need to re-encode)-c:a copy
specifies that the audio codec should be copied directly (i.e. don’t re-encode – remove this if you DO need to re-encode)output.mp4
– finally, list the name of the file you want the result written into.
See documentation here: https://ffmpeg.org/ffmpeg.html
If you need another language in the future, I think the language abbreviations are the three letter codes from here: https://en.wikipedia.org/wiki/List_of_ISO_639-2_codes – but I’m not certain on that.
Have you taken a look at this wiki page yet?
Depending on what you need one of the suggestions there may be helpful.
There is also documentation about PBF files as used by OSM if you want to do something more unusual that needs custom coding.