SaVE: sensor-assisted motion estimation for efficient h.264/AVC video encoding

Motion estimation is a key component of modern video encoding and is very compute-intensive. We present a novel Sensor-assisted Video Encoding (SaVE) method to reduce the computational complexity of motion estimation in H.264/AVC encoders, leveraging accelerometers and digital compasses that are increasingly available on mobile devices. Using these sensors, SaVE calculates the rotational movement of a camera and then infers the global motion in the camera image sensor; it subsequently employs the estimated global motion to simplify the state-of-the-art motion estimation algorithms, UMHS and EPZS used in H.264/AVC encoders. We have constructed a prototype of SaVE and report extensive evaluation of it. Our experimental results show that SaVE can reduce the computations of UMHS and EPZS algorithms by up to 27% and 18%, respectively, while achieving the same or better video quality.