user17836: Is there a tool that can adjust the loudness level of a video? 
for example I need to make the loudness to be -23 LUFS with max deviation of 0.5 lu.
is there a simple tool/cloud service that doesn't cost too much, that can do this ? 

user1871: FFmpeg's loudnorm filter can be used. Basic syntax is
ffmpeg -i in.mp4 -c:v copy -af loudnorm=I=-23:LRA=1 -ar 48000 out.mp4

The loudness range (LRA) should be 2 x max deviation.
Also see the ebur128 filter for measuring loudness.

17836: <p>Is there a tool that can adjust the loudness level of a video? </p>

<p>for example I need to make the loudness to be -23 LUFS with max deviation of 0.5 lu.</p>

<p>is there a simple tool/cloud service that doesn't cost too much, that can do this ? </p>
 1871: <p>FFmpeg's <a href="https://ffmpeg.org/ffmpeg-filters.html#loudnorm" rel="noreferrer">loudnorm</a> filter can be used. Basic syntax is</p>

<pre><code>ffmpeg -i in.mp4 -c:v copy -af loudnorm=I=-23:LRA=1 -ar 48000 out.mp4
</code></pre>

<p>The loudness range (LRA) should be <code>2 x max deviation</code>.</p>

<p>Also see the <a href="https://ffmpeg.org/ffmpeg-filters.html#ebur128-1" rel="noreferrer">ebur128</a> filter for measuring loudness.</p>
