>>907934here is the result.
in the previous command,
>crop='126:126:10*n:0'126x126 is the size of the scrolling window
10*n means to move right 10 pixels each frame. you can adjust this parameter as needed to achieve different fps.
> -frames:v 576this is the total number of frames to create. i used the width of the input image in pixels to make sure it would pan across the whole thing.
