It is simple to make a video with multiple audio tracks, sample.mp4 is a video file without any audio tracks in it, add two audio file, each for one track:
ffmpeg \
-i sample.mp4 \
-i lang1.mp4a \
-i lang2.mp4a \
-c:v copy \
-map 0:v \
-map 1:a \
-map 2:a \
-metadata:s:a:0 title="lang1" \
-metadata:s:a:1 title="lang2" \
-y \
video_with_multi_audio.mp4
How can I do it with Kdenlive or other video editor?

