stream out from difference video and audio source files

[andym]

I'm trying to use vlc to produce a mpeg2ts stream which getting video from one ts file and audio from another ts file.
I've search some information over the forums and some mentioned that parameters "--input-slave" can do it. But, I can not find the details with sample code for how to do it. And, I try as
vlc.exe -I wx -vvv music.mpg --input-slave video.mpg --sout=#duplicate{dst=std{access=udp,mux=ts,dst="239.1.1.2:1234"}}
which only audio output
vlc.exe -I wx -vvv video.mpg --input-slave music.mpg --sout=#duplicate{dst=std{access=udp,mux=ts,dst="239.1.1.2:1234"}}
which only video output

it seems --input-slave with no effect at all.

Does any expert here can help me?