How do you export an mp4 with dual audio on mpegstreamclip?

[action pack]

I have an avi file with russian and japanese audio. when I convert and export to mp4 with streamclip only one audio works. How do I retain both audio?

[Baldrick]

Does it contain TWO audio tracks? Check with mediainfo.

See also https://forum.videohelp.com/threads/306358-can-I-remove-dubbing-on-an-avi-file