Motion Vector Estimation for Bitstream Scaling

Abstract

When a reference frame is discarded for bitstream scaling, re-encoding requires detection of the new motion vectors. For software trans-coding, it is desirable to avoid this calculation since detection of the motion vectors has a high computational cost. To solve this problem, we proposed scaling the bitstream by altering a reference frame without new motion vector detection. The new motion vectors of the current frame are estimated from the motion vectors of the discarded frames. In this paper, the accuracy of the estimated motion vectors by this method are verified.