“…These include KTH (6 classes, [58]), Weizmann (10 classes, [4]), CMU Soccer (7 classes, [9]), CMU Crowded (5 classes, [27]), UCF Sports (9 classes, [53]), UR ADL (10 classes, [44]), UM Gesture (14 classes, [38]), UCF Youtube (11 classes, [41]), Hollywood-1 (8 classes, [35]), Hollywood-2 (12 classes, [43]), MultiKTH (6 classes, [70]), MSR (3 classes, [86]), and TRECVID (10 classes, [63]). These datasets contain short clips, each depicting one of a small number of classes (3)(4)(5)(6)(7)(8)(9)(10)(11)(12)(13)(14). Several more recent datasets also contain short clips, each depicting a single action, but with a larger number of action classes: UCF50 (50 classes, [52]), HMDB51 (51 classes, [33]), and UCF101 (101 classes, [65]).…”