INSERT_FILT      1936 fftools/ffplay.c             INSERT_FILT("transpose", "clock");
INSERT_FILT      1938 fftools/ffplay.c             INSERT_FILT("hflip", NULL);
INSERT_FILT      1939 fftools/ffplay.c             INSERT_FILT("vflip", NULL);
INSERT_FILT      1941 fftools/ffplay.c             INSERT_FILT("transpose", "cclock");
INSERT_FILT      1945 fftools/ffplay.c             INSERT_FILT("rotate", rotate_buf);