The block passed to exportAsynchronouslyWithCompletionHandler does not have any parameters.  It is called regardless of error state and you must inspect the AVAssetExportSession.Error property to determine if an error occured.
The block passed to exportAsynchronouslyWithCompletionHandler does not
have any parameters.  It is called regardless of error state and you must
inspect the AVAssetExportSession.Error property to determine if an error
occured.

mono/maccore,cwensley/maccore,jorik041/maccore,beni55/maccore