title: ortp library in configure and install mediastreamer2 library
body: <p>I want to make and install mediastreamer2 library and I've installed libortp-dev library.</p>
  
  <p>but after executing <code>./configure</code> in mediastreamer2 folder, I encountered this error:</p>
  
  <pre><code>configure: error: Couldn't find ortp library
  </code></pre>
  
  <p>I don't know why!?</p>
  
  <p>any help would be appreciated.</p>