The invention relates to a method of identifying a boundary (211, 212) of a content item in a content stream (201), the method comprising the steps of: (110) receiving predetermined additional data related to the content item, the additional data comprising attribute data describing substantially the whole content item, - (130) using a content-analysis processor (310) for analyzing the content stream so as to detect whether the content stream corresponds to the attribute data, and (140) identifying the boundary of the content item in the content stream when the correspondence changes from valid to invalid, or vice versa. The attribute data may indicate a genre of a movie, a music style of a song, etc. or a sequence of genres/music styles. The content-analysis processor (310) utilizes the attribute data to detect whether the content stream belongs to the content item by analyzing the content stream so as to detect the correspondence of the content stream to the attribute data.