Ok, so using the overlay filter, one can change the x/y location of a video over time by using the "t" variable. For example, overlay=x='if(gte(t,2), -w+(t-2)*20, NAN)':y=0
can be used to start sliding an overlayed element from the top left to top right, after 2 seconds has passed.
What I want to do is to use a similar principle for scaling elements. I would like to be able to change the scale of a video over time by using an expression (like, scale=w=iw*t
, or something along that line).
Is this possible?
when I run that expression through -filter_complex, I get
Error when evaluating the expression 'iw*t'.
Maybe the expression for out_w:'iw*t' or for out_h:'-1' is self-referencing.
I'm feeling like there's a fair chance I'm going to need to patch FFMpeg if I want to get this functionality, but I thought I would ask first, to see if anyone would be in the know about this kind of thing!
Does anyone know how such a task might be accomplished?
Thanks for the help!