Pixel-Wise Unified Rate-Quantization Model for Multi-Level Rate Control

Abstract

In this paper, we present a pixel-wise unified rate quantization (R-Q) model for a low-complexity rate control on configurable coding units of high efficiency video coding (HEVC). In the case of HEVC, which employs hierarchical coding block structure, multiple R-Q models can be employed for the various block sizes. However, we found that the ratios of distortions over bits for all the blocks are a nearly constant because of employment of the rate distortion optimization technique. Hence, one relationship model between rate and quantization can be derived from the characteristic of similar ratios of distortions over bits regardless of block sizes. Thus, we propose the pixel-wise unified R-Q model for HEVC rate control working on the multi-level for all block sizes. We employ a simple leaky bucket model for bit control. The rate control based on the proposed pixel-wise unified R-Q model is implemented on HEVC test model 6.1 (HM6.1). According to the evaluation for the proposed rate control, the average matching percentage to target bitrates is 99.47% and the average PSNR degradation is 0.76 dB. Based on the comparative study, we found that the proposed rate control shows low bit fluctuation and good RD performance, compared to R-lambda rate control for long sequences.Index Terms-HEVC, rate control, unified R-Q model, video coding.

A Perceptual Rate Control Algorithm with S-JND Model for HEVC Encoder

“…[15]에서 제안된 URQ (Unified Rate-Quantization) 모델 기반의 율 제어 알고리즘은 화소 단위로 목표 비트율과 QP 값 사이의 관계를 정의하여 사용한다 [16] . 현재 HM에는 [12]에서 제안된 R-λ 모델 기반의 율 제어 알고리 즘이 적용되어 있으며, 이는 주어진 비트율과 λ 간의 관계 를 기반으로 하여 QP를 결정한다 [17] .…”

Two-level sliding-window VBR control algorithm for video on demand streaming

“…Most of them are inspired in some well-known CBR-RCAs previously proposed for H.264/AVC: Naccari et al [17] and Choi et al [18] proposed CBR controllers based on that described in [19], which employed the commonly used quadratic R-Q model for QP estimation; Si et al [20] proposed an RCA based on the simple linear R-Q model stated in [21]; Wang et al [22] used for their RCA the well-known ρ-domain model described in [23]; Yoon et al [24], Sanz et al [25], Liang et al [26] and Sun et al [27] presented RCAs that use the accurate Cauchy-density-based R-Q model already proposed in [28]. This latter paper uses specifically a pre-analysis step to predict accurately the source rate.…”

Adaptive bit allocation scheme for rate control in high efficiency video coding with initial quantization parameter determination

“…It calculates Q p based on the predicted target bits and image complexity before actual encoding. In [16,17], the improvement of the pixel-wise URQ RC performance is achieved by using quantization step size instead of Q p value. In [18], a RC scheme based on a linear RÀλ model is proposed, which shows less bit-rate mismatching and better R-D performance than the RC scheme based on the pixel-wise URQ model.…”

“…In the state-of-the-art RC scheme for HEVC, the RÀλ model based RC scheme [18] is used for interframe coding and the RC scheme in [19] is adopted for intraframe coding, which is implemented in the HEVC reference software HM11.0. In [17], MAD is used as complexity measure and determined by a temporal linear prediction formula. In [18], the RÀλ model based RC scheme also employs MAD, which is predicted by that in the collocated position of the previous coded frame belonging to the same level of current frame, to characterize the complexity of residual signals.…”

“…First, comparing to the existing texture complexity measurement models of residual signals, such as MAD [16][17][18], we establish a more accurate model to estimate the video texture complexity with the consideration of spatial-temporal correlations.…”