Right click on the playing window, then select the menu item "Options..." from the popup menu to open the options dialog.
Another way is to click the "Settings" button on control panel, you will see the below options dialog.
In options dialog, there are three tabbed window "General", "Video", and "Shortcut". From "General" tabbed window, you may
preset some general settings. From "Video" tabbed window, you may preset a default video settings according to your PC quality.
From "Shortcut" tabbed window, you may define your own hot keys for repeated used operations acccording to your habits.
Click "Ok" button to save the changes and return.
Click "Cancel" button to discard the changes and return.