Abstract: The video playback technology disclosed herein gives fullscreen immersive experience to users when they watch videos on mobile devices used to watch the video. Specifically, an implementation of the technology disclosed herein gives a continuous all-time immersive experience by treating the screen of the mobile device as a window to watch a wide-angle video, and by keeping the video's relative angle to gravity unchanged while users rotate or tilt their mobile devices. In one implementation, the video also zooms in/out of the display during rotation of the smartphones, to give users a sense of getting closer/farther to the video. One or more implementations disclosed herein use inputs from gravity sensors including magnetic sensors, gyroscope, accelerometer, etc., to determine the amount of zooming in/out and shifting for the video in response to various movements, such as rotate, move, and tilt, of the video display device by the users.