Rate-distortion optimized motion smoothing for MPEG-2 encoding

A new bit allocation technique between motion vectors and DCT coefficients for MPEG-2 encoding is presented. In MPEG-2 encoding, the differential between two neighboring motion vectors is losslessly encoded by a Huffman table. In order to adjust the bit allocation for the motion vectors, a motion vector smoothing approach is taken. The motion vectors are smoothed by a low pass filter when the bit allocation for the motion vector has to be reduced. An algorithm based on the Lagrange multiplier is used to achieve the optimal balance between motion vector smoothing and DCT coefficients quantization.