In the context of OpenCV, what is `ippicv`? : <p>While building OpenCV 3.1.0 on CentOS I've been getting a hash mismatch error caused by a file called <code>ippicv_linux_20151201.tgz</code>. After some research I have found that the two prevailing solutions suggested by several people (for example <a href="https://github.com/opencv/opencv/issues/5973" rel="noreferrer">here</a>) are the following.</p>

<ol>
<li>Build again with option <code>-DWITH_IPP=OFF</code>.</li>
<li>Manually download the file <code>ippicv_linux_20151201.tgz</code> and put it in the right place.</li>
</ol>

<p>Now solution 2 above didn't work for me, and I feel a bit nervous about solution 1. My fear is that building OpenCV with <code>-DWITH_IPP=OFF</code> might prevent some things from working properly later, thus making a time bomb. My question is what is IPP? Or <code>ippicv</code>? Or ICV? I'm not even sure what to ask here. I want to know what I'm about to disable in the build before I disable it.</p>
