Efficient Rate Control for H.264 using RD-Cost
ABSTRACT A novel adaptive coding characteristic prediction scheme called RD-cost prediction model is proposed. Through this linear model and optimum bit allocation, RD-cost and texture bits budget of current basic unit can be obtained, and then the quantization parameter (QP) can be directly calculated. Simulation results show that the H.264 encoder, using the proposed algorithm, achieves a visual quality improvement up to 0.302 dB, meets better with target bit rates, produces more flat bit-rate curve and decreases more computation complexity than that using H.264 previous rate control method JVT-G012.
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ABSTRACT: Rate distortion of Intra-frame (I-frame) plays a significant role in controlling video quality for H.264/AVC. This letter presents an adaptive distortion-based Intra-rate estimation (ADIE) algorithm for H.264/AVC rate control. In this algorithm, a new rate control model is established based on the distortion by taking image complexity, buffer status, and scene change into consideration. After adaptively updating this model, our proposed algorithm is capable of providing more accurate estimation for the quantization step (Qstep) of the I-frame than other conventional methods. Experimental results show that the proposed method can significantly improve video quality (up to 1.62 dB average PSNR performance), while achieving an accurate output bit rate. More importantly, it provides a more stable visual quality which is a result of keeping the buffer occupancy steadier than other existing rate control algorithms.IEEE Signal Processing Letters 04/2009; · 1.64 Impact Factor
Conference Paper: A two-stage ρ-domain rate control scheme for H.264 encoder[Show abstract] [Hide abstract]
ABSTRACT: In this paper, we present a two-stage rate control scheme for H.264/AVC encoder. In frame-layer, a novel bit allocation method is introduced, which estimate the target frame bits based on the coding statistics of the first stage. In MB-layer, we adopt the rho-domain rate control scheme to get the refine QP of each MB for residual signal recoding. Experimental results show that our algorithm can efficiently smooth the visual quality fluctuation between frames, on the basis of meeting bit rate constraints accurately.Multimedia and Expo, 2008 IEEE International Conference on; 05/2008