To play a movie, use File/Movie/Play. The command displays a file dialog, allowing you to browse for the movie. Press "Open" to begin playback.
During playback, the Movie Player dialog is displayed. This dialog includes the standard transport buttons (Play, Pause, Stop, and Loop), and a position slider. To skip around in the movie, left-click in the position slider, or drag its thumb.
The dialog also allows you to select a range of frames. Buttons are provided for marking the range's in and out points, and for jumping to the start or end of the range. If a frame range exists while the player is looping, the selected frames are repeated. The frame range is also passed to the export dialog (see below).
The Save button brings up the Movie Export dialog. Note that if a frame range exists, it's passed to the export dialog, so that by default, only the selected frames are exported. This allows you to select an export range visually in the player, instead of entering it numerically in the export dialog.
The dialog also includes a Take Snapshot button, which exports the current frame as a snapshot.
The dialog's minimize and maximize buttons have special meanings, as follows. Minimize hides the dialog; to show it again, left-click on the window, or press any key. Maximize causes the main window (not the dialog) to become full-screen, and also hides the dialog; to exit full-screen mode, press any key.
To exit playback mode, close the Movie Player dialog, or press Esc. The normal animation resumes.