Nikon D3300 - Manual (Page 185)

165 Recording and Viewing Movies
3
Select Choose start/end point.
Press the
P button, then highlight
Choose start/end point and press 2.
4
Choose the current frame as the new
start or end point.
To create a copy that begins from the
current frame, highlight Start point
and press
J. The frames before the
current frame will be removed when
you save the copy.
To create a copy that ends at the current frame, highlight End
point and press
J. The frames after the current frame will be
removed when you save the copy.
Start point
End point
P button