user2444: 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.

user1871: 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' ...


2444: <p>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.</p>

<p>Complete:  </p>

<pre><code>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
</code></pre>

<p>The important part is this:</p>

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

<p>According to the <a href="https://ffmpeg.org/ffmpeg-filters.html#overlay-1" rel="nofollow noreferrer">ffmpeg docs</a>, <code>t</code> 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.</p>

<p>Here's the result of the command showing the choppyness:</p>

<p><a href="https://i.imgur.com/PN4Ji1P.mp4" rel="nofollow noreferrer">https://i.imgur.com/PN4Ji1P.mp4</a></p>

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

<p>===EDIT====</p>

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

<pre><code>tblend=average,framestep=2,setpts=0.25*PTS
</code></pre>

<p>at the end of the filter but before the <code>format</code> filter seems to do the trick.</p>
 1871: <p>The overlay filter draws on each base or 'main' frame as given; it does not create new frames.</p>

<p>In your command,</p>

<pre><code>ffmpeg -hide_banner -y -loop 1 -r 2 -i 'bg.png' ...
</code></pre>

<p>The <code>-r 2</code> sets the main video's framerate to 2, hence the result.</p>

<p>Use</p>

<pre><code>ffmpeg -hide_banner -y -loop 1 -framerate 30 -i 'bg.png' ...
</code></pre>
