title: CMTimeGetSeconds returns 0 instead 0.0666667
body: <p>Hello I'm trying to convert an integer which represents a frame rate into CMTime to be able to set minFrameDuration in AVCaptureScreenInput.</p>
  
  <p>Until now I have </p>
  
  <pre><code>int numberOfFrames = [self convertFrameRateStringToInt:[parameters objectForKey:@"frameRate"]];
  Float64 frameDuration = 1.0/numberOfFrames;
  NSLog(@"numberOfFrames %i - frameDuration %f",numberOfFrames, frameDuration);
  NSLog(@"timeshow %f",CMTimeGetSeconds(CMTimeMakeWithSeconds(frameDuration, 1)));
  return CMTimeMakeWithSeconds(frameDuration,1);
  </code></pre>
  
  <p>if the numberOfFrames is set to 15 frames per seconds then the frameDuration is 0.066667 therefore the parameters for CMTimeMakeWithSeconds are 0.066667 and 1 which means the CMTimeGetSeconds should return 0.066667/1 = 0.066667 but instead it returns 0.</p>
  
  <p>Can some one figures out what I'm doing wrong and explain me why ?
  Thanks. </p>
  
  <p>Edit1: I made it to work changing the function like this :</p>
  
  <pre><code>int numberOfFrames = [self convertFrameRateStringToInt:string];
  NSLog(@"timeshow %f",CMTimeGetSeconds(CMTimeMake(1, (int32_t)numberOfFrames)));
  return CMTimeMake(1, (int32_t)numberOfFrames);
  </code></pre>
  
  <p>I still can't understand why the last method didn't work</p>