Apply Zoom & Pan effect.

This filter accepts the following options:

zoom, z

Set the zoom expression. Default is 1.

x, y

Set the x and y expression. Default is 0.

d

Set the duration expression in number of frames. This sets for how many number of frames effect will last for single input image.

s

Set the output image size, default is ’hd720’.

fps

Set the output frame rate, default is ’25’.

Each expression can contain the following constants:

in_w, iw

Input width.

in_h, ih

Input height.

out_w, ow

Output width.

out_h, oh

Output height.

in

Input frame count.

on

Output frame count.

x, y

Last calculated ’x’ and ’y’ position from ’x’ and ’y’ expression for current input frame.

px, py

’x’ and ’y’ of last output frame of previous input frame or 0 when there was not yet such frame (first input frame).

zoom

Last calculated zoom from ’z’ expression for current input frame.

pzoom

Last calculated zoom of last output frame of previous input frame.

duration

Number of output frames for current input frame. Calculated from ’d’ expression for each input frame.

pduration

number of output frames created for previous input frame

a

Rational number: input width / input height

sar

sample aspect ratio

dar

display aspect ratio