This was used to resync a file whose audio was consistently 1.75 seconds behind the video track. The resulting file also contains the first 2 subtitle tracks from the original file.
vconv -i $IFILE -itsoffset 00:00:01.75 \
-i $IFILE \
-i $IFILE \
-i $IFILE \
-map 1:0 \
-map 0:1 \
-map 2:2 \
-map 3:3 \
-acodec copy -vcodec copy -scodec copy \
sync.mp4
``
Sources were [here][1].
[1]: http://lzone.de/fix%20async%20video%20with%20ffmpeg