• Title, Summary, Keyword: Fast Intra Mode Decision

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Scheme for Reducing HEVC Intra Coding Complexity Considering Video Resolution and Quantization Parameter (비디오 해상도 및 양자화 파라미터를 고려한 HEVC의 화면내 부호화 복잡도 감소 기법)

  • Lee, Hong-Rae;Seo, Kwang-Deok
    • Journal of Broadcast Engineering
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    • v.19 no.6
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    • pp.836-846
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    • 2014
  • To expedite UHD (Ultra High Definition) video service, the HEVC (High-Efficiency Video Coding) technology has recently been standardized and it achieves two times higher compression efficiency than the conventional H.264/AVC. To obtain the improved efficiency, however, it employs many complex methods which need complicated calculation, thereby resulting in a significantly increased computational complexity when compared to that of H.264/AVC. For example, to improve the coding efficiency of intra frame coding, up to 35 intra prediction modes are defined in HEVC, but this results in an increased encoding time than the H.264/AVC. In this paper, we propose a fast intra prediction mode decision scheme which reduces computational complexity by changing the number of intra prediction mode in accordance with the percentage of PU sizes for a given video resolution, and by classifying the 35 intra prediction modes into 4 categories considering video resolution and quantization parameter. The experimental results show that the total encoding time is reduced by about 7% on average at the cost of only 2% increase in BD-rate.

A fast Inter Mode Decision Based on Local Statistics in H.264/AVC (지역 통계를 이용한 H.264/AVC의 고속 인터 모드 예측)

  • Lee, Dong-Shik;Kim, Young-Mo
    • Journal of Korea Multimedia Society
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    • v.10 no.8
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    • pp.997-1003
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    • 2007
  • H.264/AVC enhances inter-frame coding performance adopting new intra and inter mode prediction in inter-frame motion prediction. H.264 encoder provides performance superior to existing standards with the prediction modes. Instead of enhanced performance, however, both predictions increase complexity of encoder and demand a lot of coding time. This paper proposes a method using local statistics of resultant intra mode, my and mode map to predict inter mode. There are relationship between intra and inter mode, and we can predict inter mode using neighboring macroblocks' resultant mode and motion vector according to the contents of frame. The experimental results show that the proposed algorithm reduces encoding time by 31% on average with a negligible loss of PSNR and bitrate.

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Fast Intra Prediction using Pixel Variation in H.264 (H.264에서 화소 변화량을 이용한 빠른 인트라 예측)

  • Lee, Tak-Gi;Kim, Sung-Min;Sin, Kwang-Mu;Chung, Ki-Dong
    • Journal of Korea Multimedia Society
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    • v.11 no.7
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    • pp.956-965
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    • 2008
  • H.264/AVC is the newest video coding standard of ITU-T VCEG and the ISO/IEC MPEG, offering a significant performance improvement over previous video coding standards. However, the computational complexity of H.264/AVC is drastically increased because of new technologies such as intra prediction, variable block size, quarter-pels motion estimation/compensation, etc. In this paper, we propose a fast intra prediction scheme which has two step processing. The first step is a fast block size decision which can be calculated only in one block without considering all cases of $4{\times}4$ block and $16{\times}16$ block. The complexity of the intra prediction can be reduced by using boundary difference values of macroblock. After selecting the block size, we can make mode decision using the neighbouring reference pixels and representative pixels of the block in the second step. The experimental results show that the proposed algorithm saved on the average 41.5% encoding time without any significant PSNR losses.

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Moment-based Fast CU Size Decision Algorithm for HEVC Intra Coding (HEVC 인트라 코딩을 위한 모멘트 기반 고속 CU크기 결정 방법)

  • Kim, Yu-Seon;Lee, Si-Woong
    • The Journal of the Korea Contents Association
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    • v.16 no.10
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    • pp.514-521
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    • 2016
  • The High Efficiency Video Coding (HEVC) standard provides superior coding efficiency by utilizing highly flexible block structure and more diverse coding modes. However, rate-distortion optimization (RDO) process for the decision of optimal block size and prediction mode requires excessive computational complexity. To alleviate the computation load, this paper proposes a new moment-based fast CU size decision algorithm for intra coding in HEVC. In the proposed method, moment values are computed in each CU block to estimate the texture complexity of the block from which the decision on an additional CU splitting procedure is performed. Unlike conventional methods which are mostly variance-based approaches, the proposed method incorporates the third-order moments of the CU block in the design of the fast CU size decision algorithm, which enables an elaborate classification of CU types and thus improves the RD-performance of the fast algorithm. Experimental results show that the proposed method saves 32% encoding time with 1.1% increase of BD-rate compared to HM-10.0, and 4.2% decrease of BD-rate compared to the conventional variance-based fast algorithm.

Adaptive Fast Algorithm for Inter/Intra Prediction in H.264 (H.264의 인터/인트라 예측을 위한 적응적 고속 알고리즘)

  • Jin, Soon-Jong;Kim, Won-Ki;Jeong, Je-Chang
    • The Journal of Korean Institute of Communications and Information Sciences
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    • v.30 no.12C
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    • pp.1153-1161
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    • 2005
  • The latest standard H.264 coding methods show better efficiency compared to the former coding standards from the rate distortion point of view, but also lead to high complexity. In this paper, we propose an adaptive and fast inter/intra prediction algorithm for H.264 video coding. In the inter prediction algorithm, an effective and simple mode selection method is proposed, which can adaptively adjust to motion estimation to reduce complexity. And proposed intra prediction algorithm reduces its complexity by using calculated Minimum Rate-Distortion costs in the prediction of Intra $16{\times}16$ and $4{\times}4$ modes. From experiment using JM8.4, our algorithm can reduce about $60.9\%$ of computation time as compared to JM, with only negligible PSNR and bitrate degradation.

An Intra Prediction Hardware Architecture Design for Computational Complexity Reduction of HEVC Decoder (HEVC 복호기의 연산 복잡도 감소를 위한 화면내 예측 하드웨어 구조 설계)

  • Jung, Hongkyun;Ryoo, Kwangki
    • Journal of the Korea Institute of Information and Communication Engineering
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    • v.17 no.5
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    • pp.1203-1212
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    • 2013
  • In this paper, an intra prediction hardware architecture is proposed to reduce computational complexity of intra prediction in HEVC decoder. The architecture uses shared operation units and common operation units and adopts a fast smoothing decision algorithm and a fast algorithm to generate coefficients of a filter. The shared operation unit shares adders processing common equations to remove the computational redundancy. The unit computes an average value in DC mode for reducing the number of execution cycles in DC mode. In order to reduce operation units, the common operation unit uses one operation unit generating predicted pixels and filtered pixels in all prediction modes. In order to reduce processing time and operators, the decision algorithm uses only bit-comparators and the fast algorithm uses LUT instead of multiplication operators. The proposed architecture using four shared operation units and eight common operation units which can reduce execution cycles of intra prediction. The architecture is synthesized using TSMC 0.13um CMOS technology. The gate count and the maximum operating frequency are 40.5k and 164MHz, respectively. As the result of measuring the performance of the proposed architecture using the extracted data from HM 7.1, the execution cycle of the architecture is about 93.7% less than the previous design.

Fast Inter/Intra Mode Decision Algorithm in H.264/AVC Considering Coding Efficiency (부호화 효율을 고려한 고속 인터/인트라 모드 결정 알고리즘)

  • Kim, Ji-Woong;Kim, Yong-Kwan
    • The Journal of Korean Institute of Communications and Information Sciences
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    • v.32 no.8C
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    • pp.720-728
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    • 2007
  • For the improvement of coding efficiency, the H.264/AVC video coding standard employs new coding tools compared with existing coding standards. However, due to these new coding tools, the complexity of H.2641AVC encoder is greatly increased. Specially, Inter/Intra mode decision method of H.264/AVC using RDO(rate-distortion optimization) technique is one of the most complex parts in H.264/AVC. In this paper, we focus on the complexity reduction in macroblock mode decision considering coding efficiency. From the simulation results, the proposed algorithm reduce the encoding time by maximum 80% of total, and reduce the bitrate of the overall sequences by $8{\sim}10%$ on the average compared with existing coding methods.

Edge-Based Fast Intra Mode Decision in HEVC

  • Na, Sangkwon;Lee, Wonjae;Lee, Kyohyuk;Yoo, Kiwon
    • Proceedings of the Korean Society of Broadcast Engineers Conference
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    • pp.180-181
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    • 2013
  • High efficiency video coding (HEVC) appears due to the demand on high compression video coding beyond H.264/AVC in ultra-high definition (UHD) videos. As for intra prediction, HEVC has 35 prediction modes while H.264/AVC has 9 intra modes. To exploit the spatial correlation, we adopt an edge detection method, establish the edge map, and adaptively select the candidate modes using the acquired edge information in a block. The number of the candidate modes is determined through trade-off between computational complexity and coding efficiency. Besides, the range of coding unit sizes is determined using the uniqueness of the edge directions for the given image block. As a result, we reduced the encoding time by 56.8% at the cost of 2.5% BD-BR increase on average compared to Full modes at the HEVC reference software (HM 6.0 [1]).

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Fast Intra Prediction Mode Decision for HEVC (HEVC의 고속 화면내 예측 모드 결정 기법)

  • Chang, Yong-Jun;Kim, Dong-Hyun;Kim, Jae-Gon
    • Proceedings of the Korean Society of Broadcast Engineers Conference
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    • pp.174-175
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    • 2013
  • HEVC의 화면내 예측 부호화는 예측 모드를 최대 35개까지 확장함으로써 기존H.264/AVC에 비해서 향상된 부호화 효율을 갖는다. 반면 화면내 부호화의 복잡도 또한 크게 증가하여 복잡도 감소를 위한 고속 부호화 기법이 요구된다. HEVC의 차조모델인 HM에서는 화면내 부호화 고속화를 위해 RMD(Rough Mode Decision) 과정을 통하여 후보 모드를 결정하고 선택된 후보 모드에서 초종 예측 모드를 결정한다. 본 논문에서는 화면내 부호화의 복잡도 감소를 위하여 고속 화면내 예측 모드 결정 기법을 제시한다. 본 기법은 후보 모드를 결정하기 위한 RMD 과정에서의 탐색 모드 수와후보 모드로부터 최종 모드를 결정하기 위한 탐색 모드 수를 제한하는 방법을 결합하여 모드 결정을 위한 복잡도를 감소한다. 본 제안 기법은 실험결과 HM 12.0대비 1.0%의 비트 증가로 13.19%의 복잡도를 감소시킬 수 있었다.

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Fast Intra-Prediction Mode Decision Algorithm using Predetermined Prediction Block Size in H.264/AVC (H.264/AVC의 인트라 예측에서 예측 블록 크기 정보를 이용한 빠른 예측 모드 결정 기법)

  • Kim, Young-ju
    • Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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    • pp.211-214
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    • 2009
  • H.264/AVC의 인트라 예측에서 미리 현재 블록 내의 정보 및 이전 블록의 예측 모드 정보 등을 이용하여 현재 블록의 예측 부호화 블록 크기가 결정되었을 경우, 예측된 블록 크기에 적합한 예측 모드 결정이 요구된다. 이에 사전에 결정된 예측 블록 크기 정보와 주변 블록과의 화소 변화량을 계산하여 예측 모드를 결정하는 기법을 제안하고 성능을 평가한다.

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