do_set_speed      792 applications/mp4client/main.c 				do_set_speed(playback_speed * 2);
do_set_speed      797 applications/mp4client/main.c 				do_set_speed(playback_speed / 2);
do_set_speed      802 applications/mp4client/main.c 				do_set_speed(-1 * playback_speed );