臺灣博碩士論文加值系統

High Efficiency Video Coding (HEVC) 是最新一代的視訊壓縮標準，目標在與目前主流標準H.264/MPEG-4 AVC 相比，在相同的視覺品質之下，達到更高的編碼效能，然而HEVC的計算複雜度也顯著的提升了許多。在本論文中提出了三種針對編碼單位分裂的提早中止演算法。利用位元率-失真成本 (Rate-Distortion Cost) 以及預測模式，建立一個可調式的閥值，計算編碼單元的位元率-失真成本，提早中止編碼單位分支的進行。根據實驗結果顯示，約可減少平均15.7% 的編碼時間，同時伴隨著可忽略的位元率-失真品質降低。

The High Efficiency Video Coding (HEVC) is the latest video compression standard developed by JCT-VC. It adopts a flexible quad-tree structured coding unit (CU). Each CU can be recursively split into four sub-CUs of equal size. At each CU depth level, various combinations of block partitioning types and prediction modes are evaluated to find the one with the least rate distortion (RD) cost. This introduces very high computation complexity.
To reduce the encoding time, we propose three early termination schemes for eliminating unpromising splitting. In the first algorithm, calculated RD costs of the parent CU and sibling CUs of the current CU are used to avoid unnecessary CU splitting. In the second scheme, an additional threshold value is employed to terminate the splitting process in advance. In the third approach, we utilize the correlationship between RD costs and prediction modes and an adaptive threshold value to make an even earlier termination decision. Experimental result shows that the proposed algorithm reduces averagely 15.7% of encoding time with negligible quality loss nor bit-rate overhead.

Abstract i
Contents ii
List of Figures iv
List of Tables v
Chapter 1 Introduction 1
Chapter 2 Overview of the HEVC Test Model 4
2-1 Picture Partitioning 4
2-2 Intra Prediction 8
2-3 Inter Prediction 9
2-3-1 Merge Mode 9
2-3-2 Motion Vector Prediction 11
2-3-3 Motion Compensation 12
2-4 Transform 12
2-5 Entropy Coding 13
2-6 Loop Filtering 14
2-6-1 Deblocking Filter 14
2-6-2 Sample Adaptive Offset (SAO) Filter 14
Chapter 3 CU Prediction and Split Process 16
Chapter 4 Related Work 19
Chapter 5 Proposed Algorithms 23
5-1 Early Detection of Unnecessary CU Splitting 24
5-2 Early Termination of CU Splitting Based on RD Costs 26
5-3 Early Termination of CU Splitting Based on Prediction Modes and RD Costs 28
5-3-1 Statistical Analysis 28
5-3-2 Early Termination Based on Prediction Modes and RD Costs 30
Chapter 6 Experimental Results 32
6-1 Test Conditions 32
6-2 Results of Early Detection of Unnecessary CU Splitting 35
6-3 Results of Early Termination of CU Splitting Based on RD Costs 38
6-4 Results of Early Termination of CU Splitting Based on Prediction Modes and RD Costs 40
Chapter 7 Conclusions 42
References 43

[1] G. Bjontegaard, “Calculation of average PSNR differences between RD-curves,” ITU-T SG16 Q.6 Document, VCEG-M33, April 2001.
[2] F. Bossen, “Common HM Test Conditions and Software Reference Configurations,” JCT-VC document, JCTVC-I1100, May 2012.
[3] F. Bossen, D. Flynn, and K. Sühring, “HEVC Reference Software Manual,” JCT-VC document, JCTVC-F634r1, July 2011.
[4] B. Bross, W. J. Han, G. J. Sullivan, J. R. Ohm, and T. Wiegand, “High Efficiency Video Coding (HEVC) Text Specification Draft 7,” JCT-VC document, JCTVC-I1003, May 2012.
[5] M. B. Cassa, M. Naccari, and F. Pereira, “Fast Rate Distortion Optimization for the Emerging HEVC Standard,” Picture Coding Symposium (PCS), pp. 493–496, May 2012.
[6] K. Choi, S. H. Park, and E. S. Jang, “Coding Tree Pruning Based CU Early Termination,” JCT-VC document, JCTVC-F092, July 2011.
[7] K. Goswami, B. G. Kim, D. S. Jun, S. H. Jung, J. W. Seok, Y. H. Kim, and J. S. Choi, “An Early Termination Algorithm for Efficient CU Splitting in HEVC,” Journal of Broadcast Engineering (JBE), vol. 18, no. 2, pp.271-282, March 2013.
[8] ITU-T and ISO/IEC JTC 1, “Advanced Video Coding for Generic Audio-Visual Services,” ITU T Rec. H.264 and ISO/IEC 14496-10 (AVC), April 2013.
[9] JCT-VC HEVC reference software version HM 7.0, available in https://hevc.hhi.fraunhofer.de/svn/svn_HEVCSoftware/tags/HM-7.0.
[10] I. K. Kim, K. McCann, K. Sugimoto, B. Bross, and W. J. Han, “High Efficiency Video Coding (HEVC) Test Model 7 (HM 7) Encoder Description,” JCT-VC document, JCTVC-I1002, May 2012.
[11] J. Kim, S. Jeong, S. Cho, and J. S. Choi, “Adaptive Coding Unit Early Termination Algorithm for HEVC,” IEEE International Conference on Consumer Electronics (ICCE), pp. 261–262, January 2012.
[12] J. Kim, J. Yang, K. Won, and B. Jeon, “Early Determination of Mode Decision for HEVC,” Picture Coding Symposium (PCS), pp. 449–452, May 2012.
[13] J. H. Lee, C. S. Park, and B. G. Kim, “Fast Coding Algorithm Based on Adaptive Coding Depth Range Selection for HEVC,” IEEE International Conference on Consumer Electronics - Berlin (ICCE-Berlin), pp. 31–33, September 2012.
[14] J. Leng, L. Sun, and T. Ikenaga, “Content Based Hierarchical Fast Coding Unit Decision Algorithm for HEVC,” Multimedia and Signal Processing (CMSP), vol. 1, pp. 56–59, May 2011.
[15] K. McCann, B. Bross, W. J. Han, I. K. Kim, K. Sugimoto, and G. J. Sullivan, “High Efficiency Video Coding (HEVC) Test Model 10 (HM 10) Encoder Description,” JCT-VC document, JCTVC-L1002, January 2013.
[16] K. McCann, B. Bross, S. Sekiguchi, and W. J. Han, “High Efficiency Video Coding (HEVC) Test Model 2 (HM 2) Encoder Description,” ITU-T/ISO/IEC Joint Collaborative Team on Video Coding (JCT-VC) document, JCTVC-D502, October 2010.
[17] L. Q. Shen, Z. Liu, X. P. Zhang, W. Q. Zhao, and Z. Y. Zhang, “An Effective CU Size Decision Method for HEVC Encoders,” IEEE Transactions on Multimedia, vol. 15, no.2, pp. 465–470, February 2013.
[18] X. L. Shen, L. Yu, and J. Chen, “Fast Coding Unit Size Selection for HEVC based on Bayesian Decision Rule,” Picture Coding Symposium (PCS), pp. 453–456, May 2012.
[19] G. J. Sullivan, J. R. Ohm, W. J. Han, and T. Wiegand, “Overview of the High Efficiency Video Coding (HEVC) standard,” IEEE Trans. Circuits and Systems for Video Technology, vol. 22, no. 12, pp. 1648–1667, December 2012.
[20] H. L. Tan, F. Liu, Y. H. Tan, and C. Yeo, “On Fast Coding Tree Block and Mode Decision for High-Efficiency Video Coding (HEVC),” IEEE International Conference on Acoustics, Speech and Signal Processing (ICASSP), pp. 825–828, March 2012.
[21] H. Wang, Y. Wee, Y. Kim, D. S. Jun, S. H. Jung, and J. S. Choi, “An Early Termination Method Using the Residual in High Efficiency Video Coding,” IEEE International Symposium on Broadband Multimedia Systems and Broadcasting (BMSB), pp. 1–2, June 2012.
[22] Q. Yu, X. F. Zhang, S. Wang, and S. W. Ma, “Early Termination of Coding Unit Splitting for HEVC,” Signal & Information Processing Association Annual Summit and Conference (APSIPA ASC), pp. 1–4, December 2012.