Fast inter mode decision using motion vector-based moving window (MVMW)

The latest video coding standard H.264/AVC achieves significant coding efficiency by adopting variable block sizes for inter mode decision. However, this technique brings about high computational complexity since the optimal mode is determined by exhaustively calculating rate-distortion cost (RDcost) of all modes. To solve this problem, fast inter mode decision algorithm is proposed, as follows. Based on high correlation between current and previous frames, the motion vector based-moving window (MVMW) scheme predicts the RDcost for each mode, and the predicted RDcosts are used as thresholds for selecting the optimal mode. The experimental results show that the proposed algorithm achieves 71.78% time saving on average with negligible PSNR loss and bit rate increment. This feature will help to develop real time video applications such as video conference and telephone.