[FFmpeg-user] Stretch/Scale only center of overlay image

[Hans Carlson]

On Thu, 13 Feb 2020, Michael Koch wrote:

> Do you mean a continuous zoom like image warping? I have a few examples 
> in my book (search for "image warping"): 
> http://www.astro-electronic.de/FFmpeg_Book.pdf

Well... maybe... but I don't think so, at least not the way it's used in 
your book.

I ONLY want to stretch horizontally.  And I want to stretch uniformly or 
at least the same way the scale filter does it.  I don't want any inward 
or outward distortion effect as in your warping examples.  If the displace 
filter can do this, I assume it depends on the equations used and I have 
no idea what those equations might be.