midi to din-sync

[Paul Perry]

Curious about converting midi clock to din sync.
The problem is, that din sync has (I believe) 4
pulses for every midi clock.

Now, stripping out the pulses from the midi line is no problem.
But, to move the frequency up 4 times without making it lumpy..

well, everything is easy if the tempo is stationary.  (I can see
how to do this in analog, simply enough). But, if it 
accelerates or decelerates rapidly, I can see bad problems.
How do people usually overcome this?
What accelertation/decelearation rates scramble existing din sync 
convertors?

paul perry Melbourne Australia