High Efficiency Video Coding Standard Research Articles

Fast coding unit selection and motion estimation algorithm based on early detection of zero block quantified transform coefficients for high‐efficiency video coding standard

High-efficiency video coding (HEVC) is the newest video coding standard developed by the joint video team, consisting of ITU-T video coding experts group and ISO/IEC Moving Picture Experts Group. The HEVC standard has aggregated an exhaustive algorithm for mode decision based on a recursive quad-tree structured coding tree block. Moreover, several specific features have been incorporated into the motion estimation (ME) process to improve its coding efficiency. However, they resulted in very high computational complexity. To accelerate the encoding process, fast mode decision algorithms for the partitioning module and also for the ME module were proposed in this study. These algorithms are based on early zero block detection technique. To improve the efficiency of these algorithms, an overall algorithm which combines the two techniques has been implemented. The performance of the proposed algorithm was checked through a comparative analysis in terms of encoding time and compression rate. Compared to HEVC test model 10.0, the authors’ proposed algorithms bring a great reduction of the HEVC complexity encoder with a saving time, which can reach 25% in average for different tested videos and a slight coding loss in terms of image quality and compression rate.

HEVC coding-unit decision algorithm using tree-block classification and statistical data analysis

We propose a fast coding unit (CU) depth decision algorithm in the High Efficiency Video Coding (HEVC) procedure based on statistical analysis. First, we derive a set of optimized weights of surrounding CU decisions to predict the current CU decision for 3 different Largest Coding Unit (LCU) classes. Second, for a given predicted current CU decision, we analyze the possible true current CU decisions, aiming to find the correspondence. A corresponding table is found and can be used to achieve target prediction accuracy. Third, for early termination of the encoding processes, the 3 early termination methods in a state-of-the-art work, as well as their different combinations, are evaluated. We show that using one of them is sufficient for saving time while encoding to keep the implementation complexity low. Compared with full CU search in HEVC standards, the proposed method reduces the encoding time by 57 and 49 % on average with Low Delay and Random Access profiles, respectively, with acceptable bitrate and PSNR performances. Compared with two state-of-the-art methods, the encoding time reduction is up to 23 and 13 % with Low Delay profile, 7 and 3 % with Random Access profile, on average, whereas the performances of bitrate and PSNR are similar.

Fast CU Encoding Schemes Based on Merge Mode and Motion Estimation for HEVC Inter Prediction

The emerging video coding standard High Efficiency Video Coding (HEVC) has shown almost 40% bit-rate reduction over the state-of-the-art Advanced Video Coding (AVC) standard but at about 40% computational complexity overhead. The main reason for HEVC computational complexity is the inter prediction that accounts for 60%-70% of the whole encoding time. In this paper, we propose several fast coding unit (CU) encoding schemes based on the Merge mode and motion estimation information to reduce the computational complexity caused by the HEVC inter prediction. Firstly, an early Merge mode decision method based on motion estimation (EMD) is proposed for each CU size. Then, a Merge mode based early termination method (MET) is developed to determine the CU size at an early stage. To provide a better balance between computational complexity and coding efficiency, several fast CU encoding schemes are surveyed according to the rate-distortion-complexity characteristics of EMD and MET methods as a function of CU sizes. These fast CU encoding schemes can be seamlessly incorporated in the existing control structures of the HEVC encoder without limiting its potential parallelization and hardware acceleration. Experimental results demonstrate that the proposed schemes achieve 19%-46% computational complexity reduction over the HEVC test model reference software, HM 16.4, at a cost of 0.2%-2.4% bit-rate increases under the random access coding configuration. The respective values under the low-delay B coding configuration are 17%-43% and 0.1%-1.2%.

Fast HEVC I-frame coding based on strength of dominant direction of CUs

High efficiency video coding (HEVC), the latest international video coding standard, greatly outperforms previous standards such as H.264/AVC in terms of coding bitrate and video quality. The coding efficiency improvement in HEVC is achieved by introducing several new techniques such as recursive quad-tree structure and increased number of intra prediction modes. However, computational load is also increased due to employing the new techniques. In this paper, we propose a solution for fast I-frame coding in HEVC standard using homogeneity of Coding Units (CUs). The proposed solution consists of two stages. In the first stage, we evaluate CU homogeneity by computing a parameter named dominant direction strength and predict CU size by this means. In the second stage, we select 11 modes out of 35 for the specified CU size based on dominant direction of the CU. Experimental results indicate that the proposed method achieves on average 45.8 % reduction on coding time, with very similar coding efficiency as the HEVC reference software. Moreover, we designed tree-stage pipelined architecture for our method which can operate at 235 MHz maximum clock rate which means it can be used for real-time coding of all intra configuration of HEVC videos up to level 6.2.

Perceptual feature guided rate distortion optimization for high efficiency video coding

With the advances in understanding perceptual properties of the human visual system, perceptual video coding, which aims to incorporate human perceptual mechanisms into video coding for maximizing the perceptual coding efficiency, becomes an essential research topic. Since the newest video coding standard—high efficiency video coding (HEVC) does not fully consider the perceptual characteristic of the input video, a perceptual feature guided rate distortion optimization (RDO) method is presented to improve its perceptual coding performance in this paper. In the proposed method, for each coding tree unit, the spatial perceptual feature (i.e., gradient magnitude ratio) and the temporal perceptual feature (i.e., gradient magnitude similarity deviation ratio) are extracted by considering the spatial and temporal perceptual correlations. These perceptual features are then utilized to guide the RDO process by perceptually adjusting the corresponding Lagrangian multiplier. By incorporating the proposed method into the HEVC, extensive simulation results have demonstrated that the proposed approach can significantly improve the perceptual coding performance and obtain better visual quality of the reconstructed video, compared with the original RDO in HEVC.

CTU splitting algorithm for H.264/AVC and HEVC simultaneous encoding

High-Efficiency Video Coding (HEVC) was conceived by the Joint Collaborative Team on Video Coding as the natural successor of the H.264/AVC standard, which has been the most extended digital video standard in all segments of the domestic and professional markets for over 10 years. HEVC roughly doubles the compression performance of H.264/AVC in Rate-Distortion terms at the expense of a high computational cost. Thus, most of the previous-generation devices can decode H.264/AVC streams but they cannot decode HEVC yet, while emerging devices are supposed to be able to decode both standards. Video providers should take advantage of bandwidth reduction using HEVC when possible, but they should also provide compatible streams to older devices, making it necessary to encode the same stream using both H.264/AVC and HEVC standards. This paper presents a coding tree unit splitting algorithm for a heterogeneous simultaneous encoding scenario which makes use of information from H.264/AVC encoder to make faster decisions in HEVC. Experimental results show that the proposed algorithm can achieve a good trade-off between coding efficiency and complexity.

Low-Complexity Intra-Coding Scheme for HEVC

Compared with H.264/AVC, the latest video standard High Efficiency Video Coding (HEVC) known as H.265 improves the coding efficiency by adopting the quadtree splitting structure which is flexible in representing various textural and structural information in images. However, the computational complexity is dramatically increased, especially in the intra-mode decision process owing to supporting more partitions and modes. In this paper, we propose a low-complexity algorithm for HEVC intra-coding, which consists of a fast coding unit (CU) size decision (FCUSD) method and a fast prediction unit (PU) mode decision (FPUMD) method. In FCUSD, unnecessary CU sizes are skipped early according to the depth level of neighboring CUs and the rate distortion (RD) cost threshold derived from the former coded frame. In FPUMD, the PU mode and RD cost correlations between different depth levels are utilized to terminate unnecessary candidate modes. Experimental results demonstrate that the proposed algorithm can achieve about 50.99 % computational complexity reduction on average with 1.18 % BD-rate increase and 0.08 dB BD-psnr loss.

Low complexity depth mode decision for HEVC-based 3D video coding

The emerging international standard high efficiency video coding (HEVC) based 3D video coding (3D-HEVC) was recently standardized by the Joint Collaborative Team on 3D video coding (JCT-3V) as an extension of HEVC for coding the multi-view video plus depth content. In test model of 3D-HEVC, new depth inter and intra modes including disparity estimation (DE), depth modeling modes (DMM) and region boundary Chain coding (RBC) are exploited for depth map coding. These new inter and intra modes achieve the highest possible coding efficiency, but it results in extremely large encoding time which obstructs 3D-HEVC from practical application. In this paper, we propose a low complexity depth mode decision algorithm for both inter and intra prediction to reduce the computational complexity of 3D-HEVC. The basic idea of the proposed algorithm is to utilize the depth map changes characteristic to predict the current depth treeblock prediction mode and early skip unnecessary inter and intra modes, such as DE, DMM and RBC. Experimental results show that the proposed low complexity algorithm can reduce the encoding time by up to 35% for 3D-HEVC mode decision, with negligible loss of rate-distortion (RD) performance.

Multiview Plus Depth Video Coding With Temporal Prediction View Synthesis

Multiview video (MVV) plus depths formats use view synthesis to build intermediate views from existing adjacent views at the receiver side. Traditional view synthesis exploits the disparity information to interpolate an intermediate view by considered inter-view correlations. However, temporal correlation between different frames of the intermediate view can be used to improve the synthesis. We propose a new coding scheme for 3-D High Efficiency Video Coding (HEVC) that allows us to take full advantage of temporal correlations in the intermediate view and improve the existing synthesis from adjacent views. We use optical flow techniques to derive dense motion vector fields (MVF) from the adjacent views and then warp them at the level of the intermediate view. This allows us to construct multiple temporal predictions of the synthesized frame. A second contribution is an adaptive fusion method that judiciously selects between temporal and inter-view prediction to eliminate artifacts associated with each prediction type. The proposed system is compared against the state-of-the-art view synthesis reference software 1-D Fast technique used in 3-D HEVC standardization. Three intermediary views are synthesized. Gains of up to 1.21-dB Bjontegaard Delta peak SNR are shown when evaluated on several standard MVV test sequences.

Optimization algorithm based on texture feature and frame correlation in HEVC

Newly proposed video standard High Efficiency Video Coding (HEVC) achieves higher compression performance than previous ones. In this paper, we propose a novel algorithm for intra prediction, which scales the complexity of pictures' texture to perform different levels of simplification on Most Probable Mode(MPM) selection. And the proposed algorithm for inter prediction initializes current Coding Unit(CU) depth information with that information of temporally adjacent frame's co-located CU. These two proposed algorithms, utilizing the texture feature and correlation of adjacent frames, reduce the computational complexity to improve the efficiency of encoder. The proposed algorithms decrease more than 30 % of encoding time with nearly negligible increment in bit-rate, especially work well when encoding sequences with high definition.

High Dynamic Range and Wide Color Gamut Video Coding in HEVC: Status and Potential Future Enhancements

As the video industry begins deployment of ultrahigh-definition TV in both professional and consumer markets, including support for higher dynamic range and wider color gamut services is considered essential within the industry. Higher dynamic range and wider color gamut offer end users a significantly enhanced viewing experience by supporting intensity ranges and colors unattainable in existing distribution ecosystems. In response to this trend, several standardization organizations have launched efforts to better enable these features in both short term and midterm. In this paper, we provide a survey of these standardization activities, with the specific goal of providing a summary of the underlying technologies. Our emphasis is on both existing and potential extensions to the High Efficiency Video Coding standard.

Ultrasound Video Streaming using HEVC-XLD in WiMAX Networks

Medical video communication system has been adopted widely in standard clinical practise to provide an adequate quality video diagnostic. In the existing m-health application, significant advance methods has been produced to emerge the high efficiency video compression methods with a promising wireless network for emergency situation in daily clinical practice. To transmit the medical ultrasound video effectively from user side to expert side, this proposed work utilize the upcoming standard technique High efficiency video coding (HEVC) for video compression. HEVC provides equal perceptual video quality by 50% bit-rate reduction range with high-resolution and low-delay video transmission. The cross layer framework over the WiMAX network is adapted to improve the throughput of the network considerably and the quality of service is optimized in the network environments. The experimental evaluations of the proposed scheme indicate that it produce a higher PSNR rate per frame and the best high resolution ultrasound video quality.

2진 MQ 산술부호기의 성능 개선

2진(binary) MQ 산술부호화는 최근 들어 멀티미디어 압축 표준시스템에 기본 엔트로피 방식으로 사용되고 있다. MQ 산술부호기는 JBIG2와 JPEG2000에 적용되면서 압축성능을 인정받기 시작했다. 최근에 차세대 동영상 부호화 표준인 HEVC (high efficiency video coding)에는 산술부호화가 단일 엔트로피부호화로 채택되면서 그 중요성이 커지고 있다. 기존의 2진 MQ 산술부호기는 RANGE(구간)을 분할하는 과정에서 곱셈을 없애면서 근사화 방법을 사용하고 있다. 이 경우 MPS/LPS의 구간이 뒤바뀌는 경우가 발생하며 출력비트가 늘어날 수 있다. 본 논문에서는 이러한 문제점을 완화하기 위하여 근사식을 사용하는 대신에 룩업테이블 형태로 AQe의 값을 양자화하여 계산에 적용하는 방법을 제안하고자 한다. 제안한 방법의 압축 성능을 실험을 통해 확인한 결과, 2진영상 압축표준 방식인 JBIG2의 경우 약 4%의 압축율의 개선을 보였다. 정지영상 압축표준인 JPEG2000의 경우 약 1%정도의 개선을 가져왔다. 룩업테이블을 사용하기 때문에 계산량이 기존방법에 비해 늘지 않는다. Binary MQ arithmetic coding is widely used recently as a basic entropy coder in multimedia coding system. MQ coder esteems high in compression efficiency to be used in JBIG2 and JPEG2000. The importance of arithmetic coding is increasing after it is adopted as an unique entropy coder in HEVC standard. In the binary MQ coder, arithmetic approximation without multiplication is used in the process of recursive subdivision of range interval. Because of the MPS/LPS exchange activity happened in MQ coder, output byte tends to increase. This paper proposes an enhanced binary MQ arithmetic coder to make use of a lookup table for AQe using quantization skill in order to reduce the deficiency. Experimental results show that about 4% improvement of compression in case of JBIG2 for bi-level image compression standard. And also, about 1% improvement of compression ratio is obtained in case of lossless JPEG2000 coding. For the lossy JPEG2000 coding, about 1% improvement of PSNR at the same compression ratio. Additionally, computational complexity is not increasing.

Review on Intra-prediction in High Efficiency Video Coding (HEVC) Standard

The objective of this paper is to provide a review of the intra prediction part in recently developed HEVC standard. HEVC (H.265) standard is the latest enhanced video coding standard which was planned to improve the rendered specifications of its preceding standard MPEG-4 (H.264).The main goal of the HEVC standardization effort is to enable significantly improved compression performance relative to existing standard H.264. For similar video quality, HEVC bit-streams consume only about half of the bitrate compare to previous standard H.264. Any video possess redundant bits in every frame. For remove this redundancy prediction process is used. Intra-picture prediction is a tool in HEVC which uses some prediction of data spatially from region to region within a specific picture, but has no dependence on other pictures in the video frames. HEVC gives higher compression comparing with previous standard H.264 because of its new features like quadtree structure, more directional intra-prediction modes. HEVC suitable for resolutions up to Ultra High Definition (UHD) video coding in the future.

HEVC fast reference picture selection

The new high efficiency video coding (HEVC) standard facilitates the realisation of ultrahigh-definition video applications. Although the compression efficiency of the HEVC standard is double that of the well-established H.264 standard, HEVC incurs a considerably higher encoding complexity. This Letter presents an algorithm aimed at expediting reference picture selection processes in HEVC encoding. The proposed algorithm is primarily based on a reference picture and block discovered using the advanced motion vector prediction (AMVP) algorithm. Two acceleration conditions are included in the proposed algorithm. The first early-decision condition entails examining the rate-distortion (RD) cost associated with AMVP, and if this cost is lower than a predefined threshold, motion estimation is confined to the AMVP-selected reference picture. Furthermore, for coding units of size 64 × 64 (N = 32) with a prediction-unit (PU) partitioning of 2N × N or N × 2N, the second PU uses the same reference picture as the first PU if the first PU satisfies the first early-decision condition. The experimental results revealed that the proposed algorithm considerably reduced the total encoding time with negligible RD degradation.

An efficient interpolation filter VLSI architecture for HEVC standard

The next-generation video coding standard of High-Efficiency Video Coding (HEVC) is especially efficient for coding high-resolution video such as 8K-ultra-high-definition (UHD) video. Fractional motion estimation in HEVC presents a significant challenge in clock latency and area cost as it consumes more than 40 % of the total encoding time and thus results in high computational complexity. With aims at supporting 8K-UHD video applications, an efficient interpolation filter VLSI architecture for HEVC is proposed in this paper. Firstly, a new interpolation filter algorithm based on the 8-pixel interpolation unit is proposed in this paper. It can save 19.7 % processing time on average with acceptable coding quality degradation. Based on the proposed algorithm, an efficient interpolation filter VLSI architecture, composed of a reused data path of interpolation, an efficient memory organization, and a reconfigurable pipeline interpolation filter engine, is presented to reduce the implement hardware area and achieve high throughput. The final VLSI implementation only requires 37.2k gates in a standard 90-nm CMOS technology at an operating frequency of 240 MHz. The proposed architecture can be reused for either half-pixel interpolation or quarter-pixel interpolation, which can reduce the area cost for about 131,040 bits RAM. The processing latency of our proposed VLSI architecture can support the real-time processing of 4:2:0 format 7680 × 4320@78fps video sequences.

An early split and skip algorithm for fast intra CU selection in HEVC

The rapid development and increase of multimedia applications, as well as the demand for higher video-quality services at restricted resources such as storage capacity, transmission bandwidth and power consumption, has brought the urgent need for more efficient video compression techniques. The new video coding standard high efficiency video coding (HEVC) has a significant superiority over its predecessor advanced video coding (AVC). HEVC is reported to halve the bit rate with the same visual quality, or a better quality with the same bit rate when compared with AVC. Beside other improvements, HEVC significantly gets its power from the use of dynamic hierarchical quad-tree structure by partitioning the frames into smaller regions called coding units (CU), by means of a rate---distortion optimization process. However, this improvement yields to a dramatic increase of high computational complexity and increased encoding time, which primarily restricts its adaptation in real-time applications. In this paper, we proposed an early CU determination algorithm for fast encoder realization to reduce the encoding time which is the most important part of the standard standing for development. The experimental results show that the proposed algorithm has approximately 45 % encoding time saving with a 4.6 % bit-rate increment, on average.

Before the Big Bang: Do we need a new video coding standard?

The necessity of a new video coding standard has been discussed since 2014. This may be the right time for us to ask ourselves if we need a new codec since we already have a handful of codecs in the market. Standardized in 1992, the JPEG standard has been the most successful standard in the acquisition, archiving, transmission, and display of still pictures. Including JPEG 2000, new image coding standards with performances substantially better than JPEG have appeared. Still, the market has proved that JPEG is the winner no matter what. Can this analogy be extended to video codecs? MPEG and VCEG jointly finished the latest video coding standard for high-efficiency video coding (HEVC) just a year ago. What could the new requirements be if a new video coding standard is necessary when the latest standard HEVC outperforms the existing video coding standards by more than 30% in compression? In this article, I have summarized what the different stakeholders within MPEG, from standards experts to market leaders, believe necessary to initiate a new standardization activity.

High‐speed low‐power very‐large‐scale integration architecture for dual‐standard deblocking filter

H.264/AVC is regarded as a popular video coding standard, and is widely used in multimedia applications. However, with an increasing demand for better quality videos, high efficiency video coding (HEVC) is all set to serve as the successor to H.264/AVC for higher resolution video applications. Since a majority of the multimedia devices have already been operating based on the H.264/AVC standard, it may not be worthwhile to completely replace the existing software and hardware components by different modules in order to adopt HEVC in such devices. Need is therefore felt to design a decoder for supporting H.264/AVC as well as HEVC, rather than attempting individual designs. This paper introduces a new dual-standard deblocking filter architecture, which supports both H.264/AVC and HEVC standards. Algorithmic verification has been done in Matlab and then an appropriate VLSI architecture has been implemented on FPGA as well as in ASIC domain. The proposed architecture takes 26 clock cycles for H.264/AVC and 14 cycles for HEVC to complete the filtering of a 16 × 16 pixel block. It consumes 5.80 mW normalised power and occupies an area equivalent to 70.1k equivalent gate at frequency of 100 MHz. The proposed architecture takes 8.42 ms to filter the 4K ultra high definition (UHD) (3840 × 2160) frame in H.264 standard, and it takes 18 ms to filter the 8K UHD (7680 × 4320) frame in HEVC standard.

Highly efficient near lossless video compression using selective intra prediction for HEVC lossless mode

Lossless coding mode of high efficiency video coding (HEVC) relies on efficient intra prediction methods for achieving higher compression. Sample based angular intra prediction (SAP) is a modification proposed for the conventional block-based intra prediction (BP) in the HEVC standard. In this paper a selective intra prediction (SIP) algorithm is proposed for lossless intra mode coding within HEVC, which uses an adaptive switching strategy between the two intra prediction methods, BP and modified SAP (MSAP), on a per pixel basis. MSAP is a modification proposed in this work to improve the prediction accuracy of SAP. The proposed SIP algorithm is a near lossless algorithm that selects the best prediction for each pixel to reduce the residual energy thereby increasing the coding efficiency. To circumvent the huge overhead required for the transmission of the selection from encoder to decoder, SIP adopts piggybacking the selection on the least-significant-bit (LSB) of the transmitted residual for each pixel. The proposed approach removes overhead at the expense of a ±1 reconstruction error for each pixel which is negligible for 8-bit or 10-bit input videos. Experimental results show significant coding gains for the proposed SIP over the HEVC anchor and similar state-of-the-art lossless coding algorithms.