An Efficient Criterion for Mode Decision in H.264/AVC (original) (raw)
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A Fast and Efficient Inter Mode Decision Algorithm for the H.264/AVC Video Coding Standard
2013
The H.264/AVC video coding standard is used in a wide range of applications from video conferencing to high-definition TV. Compared to the previous standard, the H.264/AVC has significantly better performance in terms of PSNR and visual quality at the same bit rate. It uses a complex mode decision technique based on rate-distortion optimization (RDO). Therefore, this technique introduces a high computational complexity. However, the computational complexity is one key challenge for the high efficient compression. In order to reduce the H.264/AVC complexity a new efficient and fast mode decision algorithm, based on the spatial homogeneity and temporal stationary characteristics of the current macroblock, is proposed in this paper. The experimental results show that the proposed algorithm is able to reduce up to 66,90 % of the computational complexity compared to the high complexity algorithm in the JM16.1 reference software with tolerant performance degradation.
Signal Processing: Image Communication, 2008
One of the new features in the H.264/AVC encoder is the use of Lagrangian rate-distortion optimization (RDO) method during mode decision at the macroblock level. The RDO technique has been employed in H.264/AVC for intra-prediction mode selection to achieve better coding efficiency. But the computational complexity of mode decision algorithm is extremely high. To reduce the complexity of mode decision, we propose an efficient and fast 4 Â 4 intra-prediction mode selection scheme. The proposed method reduces the candidate of the prediction modes based on the correlation between neighboring blocks and the sum of absolute transformed difference (SATD) between the original block and the intra-predicted block. Firstly, the rank of each mode is obtained based on the SATD value. Then, the candidate modes are further reduced by using the combination of rank and most probable mode. The proposed method reduces the number of candidate mode to either one or two. Simulation results demonstrate that the proposed mode decision method reduces about 91% of mode decision time and 70% of total encoding time of intracoding with ignorable degradation of coding performance.
2016
Abstract- The rate distortion optimization (RDO) enabled mode block), R(s, c, MODEIQP) is contributed by the number of decision (MD) is one ofthe most important techniques introduced by bits based on the MODE and QP. H.264/A VC. By adopting the exhaustive calculation of rate distortion, the optimal MD enhances the video encoding quality. A,- = 085X 2(QP-12)/3 (2) However, the computational complexity is significantly increased, MODE-which is a key challenge for real-time and low power consumption applications. This paper presents a new fast MD algorithm for The above exhaustive computation of rate and distortion highly efficient H264/AVC encoder. The proposed algorithm of all modes drastically increases the encoding time and the employs a dynamic group of candidate interlintra modes to reduce power consumption of encoder. It is also one of the major the computational cost. In order to minimize the performance loss incurred by improper mode selection for the previously encoded chlen ...
Fast Bit Rate Estimation for Mode Decision of H.264/AVC
IEEE Transactions on Circuits and Systems for Video Technology, 2000
To achieve the highest coding efficiency, H.264/AVC uses rate-distortion optimization technique. This means that the encoder has to code the video by exhaustively trying all the mode combinations including the different intra-and inter-prediction modes. Therefore, the complexity and computation load of video coding in H.264/AVC increase drastically compared to any previous standards. To reduce the complexity of rate-distortion cost computation, we propose a fast bit rate estimation technique to avoid the entropy coding method during intra-and inter-mode decision of H.264/AVC. The estimation method is based on the properties of context-based variable length coding (CAVLC). The proposed rate model predicts the rate of a 4 4 quantized residual block using five different tokens of CAVLC. Experimental results demonstrate that the proposed estimation method reduces about 47% of total encoding time on using intra-modes only and saves about 34% of total encoding time on using both inter-and intramodes with ignorable degradation of coding performance when the fast motion search algorithm is used. When full search motion estimation algorithm is used, the proposed algorithm reduces about 17% of total encoding time.
An Efficient Mode Decision Algorithm for H.264/AVC Encoding Optimization
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.
Mode decision optimization issues in H.264 video coding
Proceedings of the Fifth IEEE International Symposium on Signal Processing and Information Technology, 2005., 2005
The high compression efficiency ensured by the JVT H.264 video coding standard is mostly based on the adoption of a variable block-size motion estimation and mode decision. However, these advanced features imply a remarkable increase in the encoder complexity. To face the complexity issues, a number of algorithms and techniques have been developed, with the aim to speed up both the processes. In this paper, one of the algorithms proposed for Fast Mode Decision is reviewed and evaluated, with respect to the Reference Software implementation, and some improvements are suggested, in order to make its behavior adaptable to the video content.
A novel fast inter mode decision algorithm based on statistic and adaptive adjustment for H.264/AVC
2007 15th International Conference on Software, Telecommunications and Computer Networks, 2007
The advanced video coding (AVC) standard H.264 achieves better video compression performance compared with the previous standards, and one of major features is variable block sizes based mode decision (MD). However, the computational complexity is one key challenge for the high efficient compression. Taking into consideration the statistical characteristics and the adaptive adjustment, a fast Inter MD algorithm is proposed in this paper. The proposed MD algorithm is effective, and it is easy to implement. The simulation results show that the new algorithm reduces 20% processing time on average. Mostly, the losses of video are around 0.02dB, and the increase of bitrate can be limited less than 1%.
Fast mode-decision for H.264/AVC based on inter-frame correlations
Signal Processing: Image Communication, 2009
The H.264/AVC standard yields higher coding efficiency rates than other video coding standards. This is because it uses the rate-distortion optimization (RDO) technique, which selects the optimal coding mode and a reference frame for each macroblock (MB). In order to achieve this, the encoder has to encode a given block by exhaustively using all kinds of combinations (including different intra and inter-prediction modes). As a result, the computational complexity of video coding in H.264/AVC is extremely high. In this paper, two fast intra-/inter-mode-decision algorithms are proposed to reduce the complexity of the encoder. Both of these algorithms are based on the inter-frame correlation among adjacent pictures. For the fast intra-mode-decision, we used the intra-mode of the mostcorrelated MB at the reference frame to encode the current MB and the stationary property of the current MB was used for the fast inter-mode-decision. The simulation results show that the proposed algorithms significantly reduced the computational complexity with a negligible loss of PSNR and a slight increase in bitrate.
Efficient rate-distortion estimation for H.264/AVC coders
IEEE Transactions on Circuits and Systems for Video Technology, 2006
In video coders, the optimal coding mode decision for each coding block can be achieved by exhaustively calculating the rate-distortion cost, which simultaneously considers the distortion performance and the coding bit consumption of all possible modes. The best mode is chosen from the one with the minimum Lagrange cost. To avoid the expensive computation of Lagrange costs, in this paper, we propose transform-domain bit-rate estimation and distortion measures, based on quantized and inverse quantized integer transform coefficients, for the inter-mode decision in H.264/AVC coders. With the proposed scheme, entropy coding, inverse transform, and pixel-reconstructions are not required in the process. With ignorable degradation in coding performance, simulations demonstrate that the proposed estimation method achieves about 40% reduced computation time of rate-distortion cost for the inter-mode decision and saves about 17% total encoding time while combining with fast motion estimation and fast mode decision algorithms.
Complexity reduced mode selection of H. 264/AVC intra coding
2008
One of the new features in the H.264/AVC encoder is the use of Lagrangian Rate-Distortion Optimization (RDO) method during mode decision at the macroblock level. The RDO technique has been employed in H.264/AVC for intra prediction mode selection to achieve better coding efficiency. But the computation complexity of mode decision algorithm is extremely high. To reduce the complexity of mode decision, we propose an efficient and fast 4x4 intra prediction mode selection scheme. The proposed method reduces the candidate of the prediction modes based on the Sum of Absolute Transformed Difference (SATD) between the original block and the intra predicted block. Rank of each mode is obtained based on the SATD value. The candidate modes are further reduced by using the combination of rank and most probable mode. Simulation results demonstrate that the proposed mode decision method reduces about 95 % of mode decision time of intra coding with ignorable degradation of coding performance.