© The Institution of Engineering and Technology
High-efficiency video coding (HEVC) is a new video coding compression standard. As the successor to H.264/AVC, it provides better performance and supports higher resolution. However, the encoding complexity increases drastically. One of the major reasons is that the coding unit (CU) in HEVC is multi-sized and adjustable rather than fixed as in H.264. In addition, the number of prediction modes used in intra-frame coding is expanded from 9 to 35. The authors analysed the statistical correlations of CU depth to the deviation of pixels in the largest coding unit (LCU) and rate-distortion cost (RDcost). Accordingly, a fast CU decision method is proposed, which contains two steps: first, the depth to begin searching is determined according to the deviation of the LCU and then splitting the current CU further is decided according to RDcost. For intra-prediction, we also propose a fast mode selection method to reduce complexity. This method can quickly determine the modes for rate-distortion optimisation when the combination of most probable modes reveals the pattern direction. Software simulations show that the proposed methods reduce encoding time by more than 50% with an average of 1.4% increase of BD-rate compared to reference software HM12.0.
References
-
-
1)
-
2. Sullivan, G.J., Ohm, J.-R., Han, W.-J., Wiegand, T.: ‘Overview of the high efficiency video coding (HEVC) standard’, IEEE Trans. Circuits Syst. Video Technol., 2012, 22, (12), pp. 1649–1668 (doi: 10.1109/TCSVT.2012.2221191).
-
2)
-
17. Qiu, J., Liang, F., Luo, Y.: ‘A fast coding unit selection algorithm for HEVC’. IEEE Int. Conf. on Multimedia and Expo Workshops (ICMEW), July 2013, pp. 1–5.
-
3)
-
4. Lainema, J., Bossen, F., Han, W.-J., et al: ‘Intra coding of the HEVC standard’, IEEE Trans. Circuits Syst. Video Technol., 2012, 22, (12), pp. 1792–1801 (doi: 10.1109/TCSVT.2012.2221525).
-
4)
-
31. Kim, J., Jeon, B.: ‘Encoding complexity reduction by removal of N × N partition type’. JCTVC-D087, July 2011.
-
5)
-
25. Shen, L., Zhang, Z., An, P.: ‘Fast CU size decision and mode decision algorithm for HEVC intra coding’, IEEE Trans. Consumer Electron., 2013, 59, (1), pp. 207–213 (doi: 10.1109/TCE.2013.6490261).
-
6)
-
33. Kanumuri, S., Tan, T.K., Bossen, F.: ‘Enhancements to intra coding’. JCTVC-D235, January 2011.
-
7)
-
27. Zhang, H., Ma, Z.: ‘Fast intra mode decision for High Efficiency Video Coding (HEVC)’, IEEE Trans. Circuits Syst. Video Technol., 2014, 24, (4), pp. 660–668 (doi: 10.1109/TCSVT.2013.2290578).
-
8)
-
37. Bjøntegaard, G.: ‘Calculation of average PSNR differences between RD curves’. VCEG-M33, April 2001.
-
9)
-
14. Zhang, H., Ma, Z.: ‘Fast intra prediction for high efficiency video coding’. Advances in Multimedia Information Processing – PCM 2012, 2012, pp. 568–577.
-
10)
-
3. Kim, I.-K., Min, J., Lee, T., et al: ‘Block partitioning structure in the HEVC Standard’, IEEE Trans. Circuits Syst. Video Technol., 2012, 22, (12), pp. 1697–1706 (doi: 10.1109/TCSVT.2012.2223011).
-
11)
-
34. Lee, T., Chen, J., Han, W.-J.: ‘TE 12.1: Transform unit Quadtree/2-level test’. JCTVC-C200, October 2010.
-
12)
-
2. Wiegand, T., Sullivan, G.J., Bjontegaard, G., Luthra, A.: ‘Overview of the H.264/AVC video coding standard’, IEEE Trans. Circuits Syst. Video Technol., 2003, 13, (7), pp. 560–576 (doi: 10.1109/TCSVT.2003.815165).
-
13)
-
14)
-
36. Bossen, F.: ‘Common test conditions’. JCTVC-H1100, March 2012.
-
15)
-
12. Zhang, M., Zhao, C., Xu, J.: ‘An adaptive fast intra mode decision in HEVC’. 19th IEEE Int. Conf. on Image Processing (ICIP), September 2012, pp. 221–224.
-
16)
-
28. Zhang, H., Ma, Z.: ‘Early termination schemes for fast intra mode decision in high efficiency video coding’. IEEE Int. Symp. on Circuits and Systems (ISCAS), May 2013, pp. 45–48.
-
17)
-
23. Shen, L., Zhang, Z., Liu, Z.: ‘Adaptive inter-mode decision for HEVC jointly utilizing inter-level and spatiotemporal correlations’, IEEE Trans. Circuits Syst. Video Technol., 2014, 24, (10), pp. 1709–1722 (doi: 10.1109/TCSVT.2014.2313892).
-
18)
-
9. da Silva, T.L., Agostini, L.V., da Silva Cruz, L.A.: ‘Fast HEVC intra prediction mode decision based on edge direction information’. Proc. 20th European Signal Processing Conf. (EUSIPCO), August 2012, pp. 1214–1218.
-
19)
-
32. Piao, Y., Min, J., Chen, J.: ‘Encoder improvement of unified intra prediction’. JCTVC-C207, October 2010.
-
20)
-
22. Shen, L., Zhang, Z., Liu, Z.: ‘Effective CU size decision for HEVC intracoding’, IEEE Trans. Image Process., 2014, 23, (10), pp. 4232–4241 (doi: 10.1109/TIP.2014.2341927).
-
21)
-
16. Min, B., Cheung, R.C.C.: ‘A fast CU size decision algorithm for the HEVC intra encoder’, IEEE Trans. Circuits Syst. Video Technol., 2015, 25, (5), pp. 892–896 (doi: 10.1109/TCSVT.2014.2363739).
-
22)
-
5. Jiang, W., Ma, H., Chen, Y.: ‘Gradient based fast mode decision algorithm for intra prediction in HEVC’. Second Int. Conf. on Consumer Electronics, Communications and Networks (CECNet), April 2012, pp. 1836–1840.
-
23)
-
19. Shen, X., Yu, L., Chen, J.: ‘Fast coding unit size selection for HEVC based on Bayesian decision rule’. Picture Coding Symp. (PCS), May 2012, pp. 453–456.
-
24)
-
15. Alwani, M., Johar, S.: ‘A method for fast rough mode decision in HEVC’. Data Compression Conf. (DCC), March 2013, pp. 476.
-
25)
-
21. Shen, L., Liu, Z., Zhang, X., et al: ‘An effective CU size decision method for HEVC encoders’, IEEE Trans. Multimed., 2013, 15, (2), pp. 465–470 (doi: 10.1109/TMM.2012.2231060).
-
26)
-
20. Cho, S., Kim, M.: ‘Fast CU splitting and pruning for suboptimal CU partitioning in HEVC intra coding’, IEEE Trans. Circuits Syst. Video Technol., 2013, 23, (9), pp. 1555–1564 (doi: 10.1109/TCSVT.2013.2249017).
-
27)
-
29. Yang, M., Grecos, C.: ‘Fast intra encoding decisions for high efficiency video coding standard’, J. Real-Time Image Process., 2014, .
-
28)
-
6. Chen, G., Liu, Z., Ikenaga, T., et al: ‘Fast HEVC intra mode decision using matching edge detector and Kernel density estimation alike histogram generation’. IEEE Int. Symp. on Circuits and Systems (ISCAS), May 2013, pp. 53–56.
-
29)
-
10. Yu, Q., Rong, Y., He, Y.: ‘Fast intra mode decision strategy for HEVC’. IEEE China Summit & Int. Conf. on Signal and Information Processing (ChinaSIP), July 2013, pp. 500–504.
-
30)
-
13. Motra, A.S., Gupta, A., Shukla, M., et al: ‘Fast intra mode decision for HEVC video encoder’. 20th Int. Conf. on Software, Telecommunications and Computer Networks (SoftCOM), September 2012, pp. 1–5.
-
31)
-
7. Yan, S., Hong, L., He, W., et al: ‘Group-based fast mode decision algorithm for intra prediction in HEVC’. Eighth Int. Conf. on Signal Image Technology and Internet Based Systems (SITIS), November 2012, pp. 225–229.
-
32)
-
30. Shen, L., An, P., Zhang, Z., et al: ‘A 3D-HEVC fast mode decision algorithm for real-time applications’, ACM Trans. Multimed. Comput. Commun. Appl., 2015, 11, (3), pp. 34:1–23 (doi: 10.1145/2700298).
-
33)
-
18. Huang, H., Zhao, Y., Lin, C., et al: ‘Fast bottom-up pruning for HEVC intraframe coding’. Visual Communications and Image Processing (VCIP), November 2013, pp. 1–5.
-
34)
-
11. Zhang, Y., Li, Z., Li, B.: ‘Gradient-based fast decision for intra prediction in HEVC’. IEEE Visual Communications and Image Processing (VCIP), November 2012, pp. 1–6.
-
35)
-
26. Sun, H., Zhou, D., Goto, S.: ‘A low-complexity HEVC intra prediction algorithm based on level and mode filtering’. IEEE Int. Conf. on Multimedia and Expo (ICME), July 2012, pp. 1085–1090.
-
36)
-
24. Kim, J., Yang, J., Lee, H., et al: ‘Fast intra mode decision of HEVC based on hierarchical structure’. Eighth Int. Conf. on Information, Communications and Signal Processing (ICICS), December 2011, pp. 1–4.
-
37)
-
8. da Silva, T.L., da Silva Cruz, L.A., Agostini, L.V.: ‘Fast HEVC intra mode decision based on dominant edge evaluation and tree structure dependencies’. 19th IEEE Int. Conf. on Electronics, Circuits and Systems (ICECS), December 2012, pp. 568–571.
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