Fast mode decision for adaptive prediction error coding

2007

The H.264/AVC video coding standard uses the rate distortion optimization (RDO) method to improve the compression performance in the intra prediction. Whereas the computational complexity is increased comparing with previous standards due to this method, even though this standard selects the best coding mode for the current macroblock. In this paper, a fast intra mode decision algorithm for H.264/AVC encoder based on dominant edge direction (DED) is proposed. The algorithm uses the approximation of discrete cosine transform (DCT) coefficient formula. By detecting the DED before intra prediction, 3 modes instead of 9 modes are chosen for RDO calculation to decide the best mode in the 4x4 luma block. For the 16x16 luma and the 8x8 chroma, instead of 4 modes, only 2 modes are chosen. Experimental results show that the computation time of the proposed algorithm is decreased to about 71% of the full search method in the reference code with negligible quality loss.

IEEE Transactions on Circuits and Systems for Video Technology, 2005

The H.264/AVC video coding standard aims to enable significantly improved compression performance compared to all existing video coding standards. In order to achieve this, a robust rate-distortion optimization (RDO) technique is employed to select the best coding mode and reference frame for each macroblock. As a result, the complexity and computation load increase drastically. This paper presents a fast mode decision algorithm for H.264/AVC intraprediction based on local edge information. Prior to intraprediction, an edge map is created and a local edge direction histogram is then established for each subblock. Based on the distribution of the edge direction histogram, only a small part of intraprediction modes are chosen for RDO calculation. Experimental results show that the fast intraprediction mode decision scheme increases the speed of intracoding significantly with negligible loss of peak signal-to-noise ratio.

IRA-International Journal of Technology & Engineering (ISSN 2455-4480)

The emerging High Efficiency Video Coding (HEVC) standard is a new improved next generation video coding standard. HEVC aims to provide improved compression performance as compared to all other video coding standards. To improve the coding efficiency a number of new techniques have been used. The higher compression efficiency is obtained at the cost of an increase in the computational load. In HEVC 35 modes are provided for intra prediction to improve the compression efficiency. The best mode is selected by Rate Distortion Optimization (RDO) process. It achieves significant improvement in coding efficiency compared with previous standards. However, this causes high encoding complexity. This paper discuss the various fast mode decision algorithms for intra prediction in HEVC.

IEEE Transactions on Multimedia, 2000

The H.264 video coding standard significantly outperforms previous standards in terms of coding efficiency. However, this comes as a cost of extremely high computational complexity due to mode decision where variable block size Motion Estimation (ME) is employed. In this paper, we propose an efficient algorithm to jointly optimize mode decision and ME. A theoretical analysis is performed to study the sufficient condition to detect all-zero blocks in H.264, and thus adaptive thresholds are derived to early terminate mode decision and ME. Besides the aforementioned early termination technique, the proposed algorithm also introduces temporal-spatial checking, thresholds based prediction and monotonic error surface based prediction methods to skip checking unnecessary modes. Experimental results demonstrate that the proposed algorithm can significantly reduce the computational complexity of H.264 encoding while maintaining almost the same Rate Distortion (RD) performance as the original encoder.

IEEE Transactions on Consumer Electronics, 2000

The H.264/AVC video coding standard achieves a high coding efficiency compared to previous standards. However, the encoder complexity results in a very high computational cost due to motion estimation and macroblock mode decisions. In this paper, we propose a simple, content adaptive mode decision method suitable for a variety of applications. Experimental results show that the proposed algorithm effectively reduces about 60% of the encoding time with negligible quality loss in respect to the reference model and it compares favorably with two of the most recognized algorithms in the literature 1 .

2006

In the H.264/AVC coding standard, seven motion estimation modes from 4 × 4 to 16 × 16 are used to find the minimum motion compensation error for each macroblock. However, the high computation cost of the full search method in the reference software JM-9.3 makes the encoding process inefficient. Therefore, the methods of applying the SAD (sum of absolute difference), homogeneous region analysis, and edge detection are developed to determine the optimum motion estimation mode. Nevertheless, the additional computation cost of image processing still reduces the efficiency of the motion compensation process. In this paper, the spatial-temporal correlations between the current frame and reference frame are analyzed to develop a fast mode decision method in which no extra image processes are used. Furthermore, the concept of drift compensation is adopted to avoid the error accumulation phenomenon during the mode decision process. The experimental results show that the computation cost may be reduced above 60% and the average PSNR is only dropped about 0.04db.

2004

The emerging H.264-AVC video coding standard aims to significantly improve compression performance compared to all existing video coding standards. In order to achieve this, a robust rate-distortion optimization (RDO) technique is employed to select the best coding mode and reference frame for each macroblock. As a result, the complexity and computation load increase drastically. This paper presents a fast mode decision algorithm for H.264 intra prediction based on local edge information. Prior to intra prediction, an edge map is created and a local edge direction histogram is then established for each sub-block. Based on the distribution of the edge direction histogram, only a small part of intra prediction modes are chosen for RDO calculation. Experimental results show that the last intra mode decision scheme increases the speed of intra coding significantly with negligible loss of PSNR.

IEEJ Transactions on Electrical and Electronic Engineering, 2016

Modern video coding standards such as High Efficiency Video Coding (HEVC) and H.264/MPEG‐4 advanced video coding (AVC) supersede the previous coding standards because of their improved coding efficiency. These standards adopt variable block sizes in frame coding ranging from 4 × 4 to 16 × 16 and 4 × 4 to 64 × 64 for H.264/AVC and HEVC, respectively. The use of variable block sizes for inter prediction provides a significant coding gain compared to coding a macroblock (MB) using regular block size. However, this new feature greatly increases the computational complexity of the encoder when brute‐force rate distortion optimization (RDO) algorithm is used for coding parameter selection. This paper proposes an efficient inter prediction mode selection scheme based on motion homogeneity and residual complexity measures of an MB to speed up the encoding process. The motion homogeneity is assessed through the normalized motion vector (MV) field, and residual complexity is evaluated by the ...

Circuits and Systems, 2006. ISCAS …, 2006

Bin Feng, Guang-xi Zhu, Wen-yu Liu Department of Electronic and Information Engineering Huazhong Univ. of Sci. & Tech. Wuhan, HuBei Province, 430074, China Email: bfenghust~hotmailcom ... Abstract-H.264 defines 7 different coding modes for ... (MG) by using the characteristics ...

2009 Symposia and Workshops on Ubiquitous, Autonomic and Trusted Computing, 2009

In the H.264/AVC coding standard, there are seven motion estimation modes from 4×4 to 16×16 are used to find the minimum motion compensation error for each macroblock in the inter frame coding. For intra prediction coding, four prediction modes are used to encode the 8×8 chroma and 16×16 luma blocks and eight prediction directions and one DC prediction are used to encode the intra 4×4 luma block. In this study, the spatial-temporal correlations between the current frame and the reference frame are analyzed to develop a fast mode decision method for inter/intra frame encoding in which no extra image processes are used. The experimental results show that the total computation cost can be reduced above 70%, the total bit rate just increase less than 3.7 % and the average PSNR is only dropped about 0.08 dB.