man ALLEGRO_VIDEO_EVENT_TYPE (1): Allegro 5 API

SYNOPSIS

#include <allegro5/allegro_video.h>
enum ALLEGRO_VIDEO_EVENT_TYPE

ALLEGRO_EVENT_VIDEO_FRAME_SHOW - This event is sent when it is time to show a new frame. Once you receive this event, you can draw the current frame (as returned by al_get_video_frame(3alleg5)). al_get_video_frame(3alleg5) will continue returning the same frame until the next ALLEGRO_EVENT_VIDEO_FRAME_SHOW is sent.
ALLEGRO_EVENT_VIDEO_FINISHED - This event is sent when the video is finished. Depending on the backend, it may be possible to seek to an earlier part of the video and set the video to play to resume playback.

5.1.0