14. A computer program product for annotating a video, the computer program product stored on a non-transitory computer-readable medium and including instructions configured to cause a processor to execute steps comprising: displaying by a computer on a device a video player graphical user interface, the user interface including a display area for presenting a video and associated control buttons, the video including a plurality of annotated intervals; displaying, by the computer, a timeline associated with the video; displaying, by the computer in the display area, a frame of the video ; receiving, by the computer, a user selection of a region of the displayed frame; responsive to receiving the selection of the region, displaying, by the computer in the displayed frame, an annotation definition image indicating the selected region; receiving, by the computer, a user selection of a control button to create an annotation; providing, by the computer, a display area for receiving user input of annotation content; receiving, by the computer in the display area, the user input of annotation content; associating the annotation content with the displayed frame of the video and the selected region to generate an annotated video frame; ranking the plurality of annotated intervals based on a number of annotations associated with each annotated interval; indicating on the timeline a marker associated with the annotated video frame; while displaying the timeline, displaying an annotated thumbnail associated with the annotated video frame in the user interface responsive to a user interaction with the marker; and displaying indications of ranked orders with markers associated with each of the annotated intervals on the timeline.
15. The computer program product of claim 14 further comprising: receiving, by the computer, a user selection of a control button to edit the annotation; and receiving, by the computer, user input of revised annotation content.