title: AVAssetImageGenerator provides images rotated
body: <p>When obtaining a UIImage of a video via AVAssetImageGenerator, I'm getting back images rotated (well, technically they're not) when the video is shot in portrait orientation.  How can I tell what orientation the video was shot and then rotate the image properly?</p>
  
  <pre><code>AVURLAsset *asset = [[AVURLAsset alloc] initWithURL:url options:nil];
  AVAssetImageGenerator *generate = [[AVAssetImageGenerator alloc] initWithAsset:asset];
  NSError *err = NULL;
  CMTime time = CMTimeMake(0, 60);
  CGImageRef imgRef = [generate copyCGImageAtTime:time actualTime:NULL error:&amp;err];
  [generate release];
  UIImage *currentImg = [[UIImage alloc] initWithCGImage:imgRef];
  </code></pre>