The video control bar is at the bottom of the Video window and contains controls to manage the playback of a movie and the brightness and contrast adjustment.

Adjust the image
Drag the brightness slider
to adjust the brightness of the image.
Drag the contrast slider
to adjust the contrast of the image.
Control the playback of a movie
Click on the Play/Pause
buttons to play/pause the movie;
Click on the Step forward
button to advance an image;
Click on the Stop
button to stop and return to the beginning of the movie;
Drag the time slider
to move to any point of the movie.