To Stop Sending Videos for All Calls
Tap Settings from the Home view, then tap Basic > Video > Video Call Settings. 
Tap Auto Start Video Tx, and disable the setting. When disabled, your phone won’t 
automatically transmit video at the start of  all calls. 
To Automatically View All Incoming Video on the Full
Tap Settings from Home view, and tap Basic > Video > Video Call Settings. Tap 
Auto Video Full Screen, enable the setting and tap Save.