Grass Valley XtenDD v.4.2.4 - Manual (Page 319)

3. Menu Operation
3 – 172 Operating Instructions – Rev. 1 / 7.2002
Start Speed/ End Speed
If you have selected ”accelerated spline” or ”accelerated linear” as trajectory
between keyframes, these two parameters define the amount of acceleration.
”0.000” = strongest acceleration.
”1.000” = constant speed.
Start Speed Acceleration at the begin of the movement.
End Speed Acceleration at the end of the movement.