Correct perspective of video not recorded perpendicular to the screen.

A description of the accepted parameters follows.

x0, y0, x1, y1, x2, y2, x3, y3

Set coordinates expression for top left, top right, bottom left and bottom right corners. Default values are 0:0:W:0:0:H:W:H with which perspective will remain unchanged.

The expressions can use the following variables:

W, H

the width and height of video frame.

interpolation

Set interpolation for perspective correction.

It accepts the following values:

• linear
• cubic

Default value is linear.