Problem file mkv
 

I have a mkv file named "...DVDmux.ITA-JAP.x264.-#onair" . I think that there is also the japanese language, but I listen to only Italian. Unfortunately, the option "Audio streams" is in grey, why ?

It is possible that the splitter doesn't detect the second audio stream. So, if you are using Haali media splitter, try to install Gabest MKV splitter.

which version of BSPlayer do you use ?

I use Bsplayer 2.43.
What are Haali media and Gabest Mkv splitters ? How can I know which splitter I'm using ?

Ok, I have installed Gabest MKV splitter, now I can listen to Japanese language. How can I see if this file "...DVDmux.ITA-JAP.x264.-#onair" has subtitles ?

If the file did have subtitles included, you should have seen them by now. I am afraid there are no subtiles included. But you can search the internet for a subtitle and also you can include it yourself using MKVmerge.