Fast H.264/SVC inter-frame and inter-layer mode decisions based on motion activity

In the SVC extension of H.264, motion compensation of the enhancement layer is performed in both the same resolution layer and the corresponding lower layer, which results in greatly increased computational complexity. A fast inter-frame and inter-layer mode selection algorithm utilising the motion activity in the key frames of the video sequence is proposed. Statistics obtained empirically reveal that a macroblock with slow movement is more likely to be best matched by one in the same resolution layer. However, for a macroblock with fast movement, motion estimation between layers is required. This a priori knowledge forms the basis for the mode selection method proposed. Simulation results show that the algorithm can reduce the encoding time by up to 40%, with negligible degradation in rate distortion.