The following options are available:
X Origin: The starting horizontal position of the left edge of the panning window. Specifying a value that places any part of the panning window outside the source frame will produce undefined results.
X Size: The horizontal size of the panning window.
X Speed: The horizontal speed of the pan. The specified number divided by 16 gives the number of pixels to move per frame. Check the Neg box if you want right to left motion instead of the default left to right.
Y Origin: The starting vertical position of the top edge of the panning window. Specifying a value that places any part of the panning window outside the source frame will produce undefined results.
Y Size: The vertical size of the panning window.
Y Speed: The vertical speed of the pan. The specified number divided by 16 gives the number of pixels to move per frame. Check the Neg box if you want bottom to top motion instead of the default top to bottom.
Starting frame: The frame number at which to start the pan.
Ending frame: The frame number at which to end the pan.
If a pan cannot continue in a given direction because the window hits the edge of the source frame, motion in that direction will stop. If you put silly values in the edit boxes, you will get what you deserve!
Version 1.0 beta 2 [Source code]
Beta 2 fixes a problem with timeline navigation after stopping and restarting a preview.