add track of silence to qt movie

hello

i want to add a sound track to a quicktime movie. ok, so i add the 'addtrack sound' message to my jit.qt.movie object, but if i then export that to qt, when i reopen the file i don't see the added track.

i'm not sure that it's there or not. i suspect it did not get written because there was no content. so i want to effectively create a track which contains a specified number of milliseconds of silence, so i can see it in the track list on inspection.

but i don't know the most cpu efficient way to generate silence in msp, let alone write this data into a jitter track.

any help appreciated.