A system and method are provided for detecting the presence of potential commercials in a video data stream. Each of the commercials has an expected time length that is an integer multiple of a first predetermined time length, and has an overall time length that is equal to or less than a second predetermined time length. Transitions in the audio or video of the video data stream are detected and the time of the transitions are recorded. Time differences between one or more successive transitions are detected. Any time differences that are an integer multiple of the first predetermined time length, and that have an overall time length that is equal to or less than the second predetermined time length are identified. The contents of the video data stream associated with the identified time differences are flagged as potential commercials and sent to a content processing platform for further analysis.