/*! @property movieFragmentInterval @abstract Specifies the frequency with which movie fragments should be written.
@discussion When movie fragments are used, a partially written QuickTime movie file whose writing is unexpectedly interrupted can be successfully opened and played up to multiples of the specified time interval. A value of kCMTimeInvalid indicates that movie fragments should not be used, but that only a movie atom describing all of the media in the file should be written. The default value of this property is ten seconds.
Changing the value of this property will not affect the movie fragment interval of the file currently being written, if there is one. */ @property(nonatomic) CMTime movieFragmentInterval;