Method 1-
Go to Preferences > Advanced > Advanced and add this to the list of actions:
normal_speed inc_speed inc_speed inc_speed inc_speed inc_speed
(write inc_speed 5 times to increase speed from 1X to 1.5X & so on)
Go to Preferences > Advanced > Advanced and add this to the list of actions:
normal_speed inc_speed inc_speed inc_speed inc_speed inc_speed
(write inc_speed 5 times to increase speed from 1X to 1.5X & so on)
Method 2-
Go to Preferences > Advanced > MPlayer/mpv > Options for MPlayer/mpv > Options & add this to pass options to MPlayer/mpv:
-speed 1.5