Methods and systems for identifying black frames within a sequence of frames are provided. In one embodiment, the detection system detects black frames within a sequence of frames by fully decoding base frames and then partially decoding non-black, non-base frames in a way that ensures the blackness of each frame can be determined. The detection system decodes base frames before decoding dependent frames, which is referred to as processing frames in reverse order of dependency since a frame is processed before the frames that depend on it are processed. In another embodiment, the detection system determines the blackness of frames within a sequence of frames by processing the frames in order of their dependency and following chains of block dependency to decode and determine the blackness of blocks.