Dong-San Jun

Dynamic and Interoperable Adaptation of SVC for QoS-Enabled Streaming

For seamless streaming of multimedia contents that ensures quality of service (QoS) over heterogeneous network, we propose a flexible and low-complexity adaptation scheme of scalable video coding (SVC) using MPEG-21 digital item adaptation (DIA). For adaptation, delivery, and consumption of SVC, the proposed scheme was simulated via various time-varying constraints of network condition, terminal capability, and user preference, which showed robustness and efficiency in dynamic and interoperable adaptation of SVC.

An efficient inter prediction mode decision method for fast motion estimation in HEVC

High Efficiency Video Coding (HEVC) has been developed as the newest video coding standard which achieves the goal of 50% bit-rate reduction with similar video quality compared to the previous standard, H.264/AVC. In order to achieve this improved coding performance, HEVC adopts various advanced techniques, which require heavy encoding complexity. Similar to the previous video coding standards, HEVC has the most computational complexity to perform motion estimation of inter prediction process. Proposed method can select one inter prediction mode and perform the motion estimation only on the selected inter prediction mode. Experimental results show that the prosed method reduces the computational complexity while minimizing the coding loss.

A Fast Intra Prediction Method using Hadamard Transform in High Efficiency Video Coding

For the higher coding performance than the previous video coding standards, high efficiency video coding (HEVC) adopts an angular intra prediction method, which requires heavy computational complexity due to the increased intra prediction modes. In this paper, we propose a fast intra prediction mode decision based on the estimation of rate distortion cost using Hadamard transform to reduce the number of intra prediction mode and early termination whether the current coding unit is splitted or not. The experimental results show that the proposed method reduces the computational complexity of intra prediction in HEVC and achieves similar coding performance to that of HEVC test mode 2.1

A new rate control method for hierarchical video coding in HEVC

In this paper, we propose a new rate control (RC) algorithm for hierarchical video coding of high efficiency video coding (HEVC). To achieve a constant target bitrate transmission, an effective bit allocation method is first introduced, which assigns the number of target bits to each intra-period, group of picture, and frame by considering the hierarchical structure. A quantization parameter (QP) is determined by using the Cauchy distribution based rate-quantization (RQ) model. We further introduce a novel method to estimate the parameters of the RQ model precisely by employing the linear rate model. Experimental results show that the proposed RC algorithm controls the bitrate accurately with negligible degradation of PSNR.

An early termination method using the residual in High Efficiency Video Coding

After the success of H.264/AVC, a next generation codec for Ultra-HD resolution video is being developed under the name called High Efficiency Video Coding(HEVC). This paper presents an optimization method for HEVC by performing early termination that preventing further CU split. In our experiments, the early termination method reduces the computational complexity without noticeable coding loss.

Complexity reduction algorithm for prediction unit decision process in high efficiency video coding

To provide very high quality and/or high resolution video content under limited bandwidth conditions for transmission or storage, the high efficiency video coding (HEVC) has been recently finalised by the joint collaborative team on video coding. In this study, the authors propose a fast prediction unit (PU) decision method to reduce the computational complexity of HEVC encoder. They use an early PU decision in each coding unit-level based on spatio-temporal analyses and depth correlations. They also consider a classification of motion activity. Experimental results show that the encoding complexity can be reduced by up to 38% on average in the random access main profile configuration with only a small bit-rate increment and a peak signal to noise ratio (PSNR) decrement, compared to high efficiency video coding test model (HM) 7.0 reference software.

Development of an ultra-HD HEVC encoder using SIMD implementation and fast encoding schemes for smart surveillance system

High efficiency video coding (HEVC) is the newest video coding standard that can support powerful video compression performance with increased picture resolution for ultrahigh definition (UHD). Compared to the previous standard, HEVC achieved a coding efficiency double with a tremendous increase in encoder computational complexity, making support of commercial applications for UHD video service difficult. Especially, optimized HEVC encoder for UHD is expected to be deployed as a key technology for an emerging smart surveillance system in Internet of Things environment. Single-instruction-multiple-data implementation on an Intel x86 processor and several fast encoding schemes were investigated for the complexity reduction of the HEVC reference model (HM) encoder. Fast encoding schemes included early termination processes and data-level parallel processing. The computational complexity of the proposed HEVC encoder was decreased by approximately 192 times compared with HM encoder with an acceptable coding loss.

Fast motion estimation using priority-based inter-prediction mode decision method in high efficiency video coding

The latest video coding standard, high efficiency video coding (HEVC), is developed to acquire a more efficient coding performance than the previous standard, H.264/AVC. To achieve this coding performance, elaborate coding tools were implemented in HEVC. Although those tools show a higher coding performance than H.264/AVC, the encoding complexity is heavily increased. Especially, motion estimation (ME) requires the most computational complexity because that is always performed on three inter-prediction modes: uni-directional prediction in List 0 (Uni-L0), uni-directional prediction in List 1 (Uni-L1), and bi-prediction (Bi). In this paper, we propose a priority-based inter-prediction mode decision method to reduce the complexity of ME caused by inter-prediction. The proposed method computes the priorities of all inter-prediction modes and decides whether ME is performed or not. Experimental results show that the proposed method reduces the computational complexity of ME up to 55.51% while maintaining similar coding performance compared to HEVC test model (HM) version 10.1.

A Rate-Distortion cost estimation approach to fast intra prediction in Video Coding for Ultra High Definition TV applications

For large resolution video materials used such as in Ultra High Definition TV applications, high efficiency video compression techniques with a low complexity is highly desirable. In this paper, we propose a fast intra prediction method based on the Rate Distortion cost estimation. The proposed method reduce the computational complexity of the new generation encoder with comparable image quality and bit-rate.

Efficient biprediction decision scheme for fast high efficiency video coding encoding

Abstract. An efficient biprediction decision scheme of high efficiency video coding (HEVC) is proposed for fast-encoding applications. For low-delay video applications, bidirectional prediction can be used to increase compression performance efficiently with previous reference frames. However, at the same time, the computational complexity of the HEVC encoder is significantly increased due to the additional biprediction search. Although a some research has attempted to reduce this complexity, whether the prediction is strongly related to both motion complexity and prediction modes in a coding unit has not yet been investigated. A method that avoids most compression-inefficient search points is proposed so that the computational complexity of the motion estimation process can be dramatically decreased. To determine if biprediction is critical, the proposed method exploits the stochastic correlation of the context of prediction units (PUs): the direction of a PU and the accuracy of a motion vector. Through experimental results, the proposed method showed that the time complexity of biprediction can be reduced to 30% on average, outperforming existing methods in view of encoding time, number of function calls, and memory access.