MPMoviePlayerController thumbnail images issue

We have a http live streaming开发者_JS百科 running on our iOS app. We want to get thumbnail images every 1 minute. I tried using MPMoviePlayerController methods

thumbnailImageAtTime:timeOption: 

and

requestThumbnailImagesAtTimes:timeOption:

But both these options return nil. The documentation doesn't say if these methods do not work for http live streaming. Any ideas what could be the issue?

Now documentation for this method says: "This method is not not called when the source URL is an HTTP Live Streaming (HLS) content source. See HTTP Live Streaming Overview."

Try registering for MPMoviePlayerThumbnailImageRequestDidFinishNotification before calling this method and on getting notification check value of this key MPMoviePlayerThumbnailImageKey. In case image capture was successful value of this key will contain a valid UIImage for you to use.