BIN LI, HOUQIAN LI, LI LI, AND JINLEI ZHANG IEEE TRANSACTIONS ON IMAGE PROCESSING, VOL.23, NO.9, SEPTEMBER

Overview 2

Introduction 3

Two steps of rate control : ◦1. Allocate proper number of bits to each coding level (GOP, picture, basic unit, etc.) ◦2. Achieve the pre-allocated bits for each level. E.g., with other parameter fixed(mode, motion, etc.), larger QP generally leads to smaller bit-rate. 4

Introduction Step1Step2 5

Introduction 6

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Reference [4] K.-P. Lim, G. Sullivan, and T. Wiegand, Text Description of Joint Model Reference Encoding Methods and Decoding Concealment Methods, document Rec. JVT-N046, Hong Kong, China, Jan [10] Z. He, Y. K. Kim, and S. K. Mitra, “Low-delay rate control for DCT video coding via ρ-domain source modeling,” IEEE Trans. Circuits Syst. Video Technol., vol. 11, no. 8, pp. 928–940, Aug [11] M. Liu, Y. Guo, H. Li, and C. W. Chen, “Low-complexity rate control based on ρ-domain model for scalable video coding,” in Proc. 17 th IEEE Int. Conf. Image Process. (ICIP), Sep. 2010, pp. 1277–1280. [16] S. Ma, W. Gao, and Y. Lu, “Rate-distortion analysis for H.264/AVC video coding and its application to rate control,” IEEE Trans. Circuits Syst. Video Technol., vol. 15, no. 12, pp. 1533–1544, Dec [18] Y. Liu, Z. G. Li, and Y. C. Soh, “A novel rate control scheme for low delay video communication of H.264/AVC standard,” IEEE Trans. Circuits Syst. Video Technol., vol. 17, no. 1, pp. 68–78, Jan [19] H. Wang and S. Kwong, “Rate-distortion optimization of rate control for H.264 with adaptive initial quantization parameter determination,” IEEE Trans. Circuits Syst. Video Technol., vol. 18, no. 1, pp. 140–144, Jan [20] S. Hu, H. Wang, and S. Kwong, “Adaptive quantization-parameter clip scheme for smooth quality in H.264/AVC,” IEEE Trans. Image Process., vol. 21, no. 4, pp. 1911–1919, Apr [21] Z. He and S. K. Mitra, “Optimum bit allocation and accurate rate control for video coding via ρ-domain source modeling,” IEEE Trans. Circuits Syst. Video Technol., vol. 12, no. 10, pp. 840–849, Oct [22] Y. Pitrey, Y. Serrand, M. Babel, and O. Deforges, “Rho-domain for low-complexity rate control on MPEG-4 scalable video coding,” in Proc. 10th IEEE Int. Symp. Multimedia, Dec. 2008, pp. 89–96. [23] Y. Pitrey, M. Babel, and O. Deforges, “One-pass bitrate control for MPEG-4 scalable video coding using ρ-domain,” in Proc. IEEE Int. Symp. Broadband Multimedia Syst. Broadcast. (BMSB), May 2009, pp. 1–5. 9

Overview 10

Several types of R-D model have been proposed to characterize the relationship between R and D. 1.Exponential function [31]: 2.Hyperbolic function [32][33]: 11

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Overview 14

Rate Control Algorithm 1.Bit allocation ◦For the First Picture ◦For GOP Level ◦For Picture Level ◦For Basic Unit Level 2.Achieve the target bit-rate for a specific unit (Rate Control Coding) 15

Bit Allocation 40 16

Bit Allocation 17

Bit Allocation For basic unit(CTU in HEVC) level : Similar to picture level bit allocation 18

Rate Control Coding 19

Rate Control Coding Different level may have different parameter Target bit-rate corresponding to different level 20

Rate Control Coding

Overview 22

Experiment Design 23

Experimental Results 24

Experimental Results 25

Experimental Results 26

Experimental Results 27

Experimental Results 28

Experimental Results 29

Experimental Results 30

Overview 31

Conclusion 1.The difference between actual and target bitrate with proposed method is rather small and has a very high control accuracy. 2.Both the R-D performance and subjective quality of proposed method are better than rate control in HM While hierarchical bit allocation is disabled, the proposed method can keep almost constant bit for every picture. 32