A method for performing client side latency enhancement, a host processor and a processing circuit thereof

A method and apparatus for performing client side latency enhancement with aid of cloud game server side image orientation control. The method may include: utilizing at least one orientation-related sensor in a client device to detect a client device orientation of the client device; utilizing a network interface circuit in the client device to notify a cloud game server of the client device orientation; utilizing the cloud game server to rotate video contents of a cloud game in advance for the client device according to the client device orientation to generate pre-rotated video contents, for being output to the client device through video streaming; and utilizing the network interface circuit to receive the pre-rotated video contents through the video streaming and buffering the pre-rotated video contents in a video buffer, for being output to a display panel and displayed on the display panel.