<title>Fast motion estimation algorithm for H.264/MPEG-4 AVC by using multiple reference frame skipping criteria</title>

Abstract

The emerging video coding standard, H.264/MPEG-4 AVC, allows using multiple reference frames for motion estimation to enhance temporal prediction. Exhaustive search requires a lot of computation, which is proportional to the number of searched frames. However, the reduction of prediction residues is highly dependent on the characteristics of video sequences. In many cases, searching more reference frames contributes to nothing but only waste of computation. In this paper, we proposed a novel algorithm to accelerate the motion estimation by using reference frame skipping criteria. We adopted selected macroblock mode, intra/inter macroblock prediction residues, discontinuity of motion vectors, and scene changes in the criteria. By using these criteria, each macroblock can determine whether it is necessary to keep on searching more reference frames after the block matching process in the first reference frame. Simulation results show that the proposed algorithm can save up to 67% of ME computation without noticeable degradation of video quality.

Fast multiple reference frame motion estimation for H.264/AVC

“…6 [3], exhaustive motion search algorithm and a fast motion search algorithm are supported. In both cases, the MV search process is the most computationally intensive part in video encoders.…”

“…In [4], a fast algorithm is proposed to speed-up the MRF-ME by considering the different subpixel sampling position of each block, and performing ME on the selected reference frames with similarly sampled contents. In [5] and [6], several heuristics are used to decide whether it is necessary to search more than the most recent reference frame, and hence reduce the computations. In [7], a fast multiframe ME algorithm based on motion vectors (MVs) reusing similar to our basic ideas described in [8], [9] is independently proposed.…”

“…The reference software of AVC JM 8. 6 [3] performs the ME for all block-sizes across all reference frames in the encoder. In [4], a fast algorithm is proposed to speed-up the MRF-ME by considering the different subpixel sampling position of each block, and performing ME on the selected reference frames with similarly sampled contents.…”

Complexity Reduction Algorithm for Intra Mode Selection in H.264/AVC Video Coding

“…Since transform and entropy coding should be carried out for each coding mode in RDO procedure, it requires very large computational complexity compared to the conventional standards such as MPEG-4 part 2 and H.263, thereby it makes the H.264/AVC standard difficult to apply directly to low complexity devices such as mobile devices. Many algorithms have been proposed to reduce the computational complexity, such as fast motion estimation [3,4] and fast inter mode selection algorithm [5,6], etc. Fast motion estimation is a steady-studied subject through various standards and applications.…”