Abstract: A video detector that detects black frames in a video includes a grayscale converter, a parser for parsing the grayscale video into a sequence of individual frames, a sub-frame parser for parsing frames of an uneven block size into two or more sub-frames, and a DCT calculator. The detector extracts a DC component or AC component, or both, of the generated DCT and then compares them against respective threshold values. The individual frames are identified as a black frame based on a comparison between the selected component and the threshold value. Methods of detecting black frames based on DC components and AC components are also described.