How do I add another audio stream to an MP4 file?

I've got an MP4 video file and I want to add another AAC audio track to it. I've tried YAMB and MeGUI (frontends for MP4Box) and it plays correctly in Zoom Player, but it picks the wrong track in WMP and plays both at once in Quicktime. I think this might have to do with designating the default audio track somehow.

Does anyone know how to specify the default audio track with YAMB/MeGUI or know of another way of adding a track to an MP4 file?

Solution 1:

After a lot of scavenging around, I've found the best answer I believe. You need to use the Mp4Box command line interface to mux your MP4 file:

mp4box -new -add original_video.mp4 -add extra_track.m4a:disable output_file.mp4

This disable option will cause Quicktime to ignore that track and only play the main one. Quicktime doesn't have the ability to pick audio tracks because it's an awful piece of software, so that's the best you can do.

For WMP, you can switch audio tracks, by going to full screen mode, and then right clicking on the video. It's just that it picks the wrong track by default and you have to live with that. It's a bug in WMP.