This tool might be of use: http://mpgtx.sourceforge.net/
From the Examples section:
I want to split this file at 699 Megs so that it can fit on my Video CD!
mpgtx -s file
Now processing Chunk 1/2 ... 100.00%
Now processing Chunk 2/2 ... 45.31%Here are chunk-1.mpg and chunk-2.mpg (default basename is chunk)
Not sure if it works with your video format though.