title: Undefined symbols for architecture i386: "_CMTimeMake", referenced from:
body: <p>I don't understand why this is happening. I'm trying to us CMTimeMake:</p>
  
  <pre><code>CMTime cmTime = CMTimeMake(60, 1);
  </code></pre>
  
  <p>The imports of <code>.h</code> are:</p>
  
  <pre><code>#import &lt;UIKit/UIKit.h&gt;
  #import &lt;MediaPlayer/MediaPlayer.h&gt;
  #import &lt;AVFoundation/AVFoundation.h&gt;
  </code></pre>
  
  <p>and <code>.m</code> are:</p>
  
  <pre><code>#import "ViewController.h"
  #import "ContentView.h"
  #import "AppDelegate.h"
  #import "BackButton.h"
  #import "NavButton.h"
  #import "IIViewDeckController.h"
  #import "TutorialView.h"
  </code></pre>
  
  <p>With a build error of:</p>
  
  <pre><code>Undefined symbols for architecture i386:
    "_CMTimeMake", referenced from:
        -[ViewController activateLockScreenPlayer:] in ViewController.o
  ld: symbol(s) not found for architecture i386
  clang: error: linker command failed with exit code 1 (use -v to see invocation)
  </code></pre>
  
  <p>What am I missing?</p>