How do I add an external audio track to a video?

Question

Apache HTTP Server

Hello.

How to embed an external audio track in . mkv file. And make it the default audio track.

Answer 1

if it helps someone, then the script was under Apache, changed to nginx and it all worked. os centos 7.

Answer 2

writes sh: line 0: cd: HOME not set
cannot go to directory /var/www/dar.ru

And how can you see what should go there?
means go to home directory.

Answer 3

For removing/adding tracks/subtitles and more, I like MKVToolNix. First of all, because the GUI, in the second - because it just glues together, without recoding.

Answer 4

Ffmpeg can, download it, such a typical operation can be googled in a minute.