title: Build advance equaliser in iOS
body: <p>I build a music player app using AVplayer. The app access and play songs from iPod library. This is how I play mediaItem using <code>AVPlayer</code></p>
  
  <pre><code>MPMediaItem *mediaItem = ...
  NSURL *assetUrl = [mediaItem valueForProperty:MPMediaItemPropertyAssetURL];
  AVPlayerItem *playerItem = [AVPlayerItem playerItemWithURL:assetUrl];
  self.player = [AVPlayer playerWithPlayerItem:playerItem];
  </code></pre>
  
  <p>I need to add graphical equaliser to my app to allow users to change the following values</p>
  
  <p><img src="https://i.stack.imgur.com/QsxKO.png" alt="enter image description here"> <img src="https://i.stack.imgur.com/yMdzQ.png" alt="enter image description here"></p>
  
  <p>It seems audio processing in iOS is different from other frameworks. I did an R&amp;D and found </p>
  
  <ul>
  <li>Audio unit </li>
  <li>MTAudioProcessingTap</li>
  <li>NVDSP</li>
  <li>Novocaine</li>
  <li>OpenAL</li>
  </ul>
  
  <p>My questions are,
  Is it possible to create custom equaliser with AVPlayer?
  What technology should I use for my requirement (creating a custom equaliser with AVPlayer)?</p>
  
  <p>P.S. Can any one give a simple working example which I can add to the project and check the changes in the song (I tried the apple documentations, but it is not clear)</p>
  
  <p><strong>Update</strong></p>
  
  <p>btw I built my own eq &amp; processing lib 
  <a href="https://github.com/clementprem/CPAudioPlayer" rel="nofollow noreferrer">https://github.com/clementprem/CPAudioPlayer</a></p>