I am using the iOS YouTube Player helper (https://developers.google.com/youtube/v3/guides/ios_youtube_helper) and it works just fine but the preview image is not the size of
I find another solution. If you use YTPlayerView in a xib file, please make sure the following points.
1, Check 'Use Auto Layout'
2, DO NOT set the width and height value for YTPlayerView.
then the YTPlayerView will play normally.