Using a global optimization, a cycle within a frame buffer including frames corresponding to one or more cycles of query activity sequences is detected. The detection includes creating a plurality of cycle segmentations by recursively iterating through the frame buffer to identify candidate cycles corresponding to cycles of a reference activity sequence until the frame buffer lacks sufficient frames to create additional cycles, computing segmentation errors for each of the plurality of cycle segmentations, and identifying the detected cycle as the one of the plurality of cycle segmentations having a lowest segmentation error. Cycle duration data for the detected cycle is generated. Frames belonging to the detected cycle are removed from the frame buffer. The cycle duration data is output.