Squashfs images can be unpacked in windows with 7-zip.
The main fork 7-zip doesn't support lz4 compression, but 
<a href="https://github.com/mcmilk/7-Zip-zstd/releases">this one</a> does.
<p>
In linux, they can be directly mounted or mounted with squashfuse.  For example, either:
<ul>
<li>mount directly with the command: <tt>sudo mount -o loop,ro image1.sq /mnt/image1</tt> (no additional software needed)
<li>mount with squashfuse:  <tt>mkdir image1; squashfuse image1.sq image1</tt>
</ul>

The .sq file is squashfs and contains identical data to the .zip file (2.8G)
<p>
Files:
<ul>
<li><a href="UCF101-DS.zip">UCF101-DS.zip</a>
<li><a href="UCF101-DS.sq">UCF101-DS.sq</a>
<li><a href="ucf101-DS_eval.csv.gz">ucf101-DS_eval.csv.gz</a> (annotations, 32k)
</ul>