ffmpeg overlay image moving is choppy

Question

Using overlay to move a image from left to right feels very stuttery, as if it's moving every 0.5 second instead of per frame.

Complete:

ffmpeg -hide_banner -y -loop 1 -r 2 -i 'bg.png' -i 'centerpiece.png' -t 30 -c:v libx264 -filter_complex "[1:v]scale=iw*2.2:ih*2.2[scaled_cen],[0:v][scaled_cen]overlay=(main_w-overlay_w)/3+(t*10):(main_h-overlay_h)/2,format=pix_fmts=yuv420p" -r 30 output.mp4

The important part is this:

[scaled_cen]overlay=(main_w-overlay_w)/3+(t*10):(main_h-overlay_h)/2

According to the ffmpeg docs, t is evaluated in seconds, but I've read elsewhere that its evaluated in MS, in any case I'd like my centerpiece to move a little bit every frame.

Here's the result of the command showing the choppyness:

https://i.imgur.com/PN4Ji1P.mp4

So far i've tried things like the blur filter and minterpolate but I'm guessing the problem resides in getting t more granular or doing tricks with the fps.

===EDIT====

After applying the answer of Mulvya it still seemed a bit jittery, but adding:

tblend=average,framestep=2,setpts=0.25*PTS

at the end of the filter but before the format filter seems to do the trick.

Answer 1

The overlay filter draws on each base or 'main' frame as given; it does not create new frames.

In your command,

ffmpeg -hide_banner -y -loop 1 -r 2 -i 'bg.png' ...

The -r 2 sets the main video's framerate to 2, hence the result.

Use

ffmpeg -hide_banner -y -loop 1 -framerate 30 -i 'bg.png' ...