• Title, Summary, Keyword: Fast Intra Mode Decision

Search Result 78, Processing Time 0.044 seconds

Fast Intra Prediction in HEVC using Transform Coefficients and Coded Block Flag (변환계수와 CBF를 이용한 HEVC 고속 화면 내 예측)

  • Kim, Nam-Uk;Lee, Yung-Lyul
    • Journal of Broadcast Engineering
    • /
    • v.21 no.2
    • /
    • pp.140-148
    • /
    • 2016
  • HEVC(High Efficient Video Coding) has twice times better compression ratio than H.264/AVC, but since the computational complexity has significantly increased in the encoder side, it may cause difficulty in real-time SW implementation in the encoder side. This paper proposes two methods about fast intra prediction. First, fast mode and prediction unit decision method using transform coefficients of the original block is proposed. and second, fast prediction unit decision method using coded block flag(cbf) is proposed. The proposed method achieves 42% encoder speed up with 0.8% bitrate increase compared with HM16.0.

Fast Algorithm for Intra Prediction of HEVC Using Adaptive Decision Trees

  • Zheng, Xing;Zhao, Yao;Bai, Huihui;Lin, Chunyu
    • KSII Transactions on Internet and Information Systems (TIIS)
    • /
    • v.10 no.7
    • /
    • pp.3286-3300
    • /
    • 2016
  • High Efficiency Video Coding (HEVC) Standard, as the latest coding standard, introduces satisfying compression structures with respect to its predecessor Advanced Video Coding (H.264/AVC). The new coding standard can offer improved encoding performance compared with H.264/AVC. However, it also leads to enormous computational complexity that makes it considerably difficult to be implemented in real time application. In this paper, based on machine learning, a fast partitioning method is proposed, which can search for the best splitting structures for Intra-Prediction. In view of the video texture characteristics, we choose the entropy of Gray-Scale Difference Statistics (GDS) and the minimum of Sum of Absolute Transformed Difference (SATD) as two important features, which can make a balance between the computation complexity and classification performance. According to the selected features, adaptive decision trees can be built for the Coding Units (CU) with different size by offline training. Furthermore, by this way, the partition of CUs can be resolved as a binary classification problem. Experimental results have shown that the proposed algorithm can save over 34% encoding time on average, with a negligible Bjontegaard Delta (BD)-rate increase.

HEVC Fast Intra Mode Decision based on Most Probable Mode and Rough Mode Decision Cost (Most Probable Mode 와 Rough Mode Decision 비용을 함께 고려하는 HEVC 고속 화면내 부호화 모드 결정 방법)

  • Gwon, Daehyeok;Han, Heeji;Kim, Minseop;Choi, Haechul
    • Proceedings of the Korean Society of Broadcast Engineers Conference
    • /
    • /
    • pp.141-142
    • /
    • 2015
  • 본 논문에서는 HEVC(High Efficiency Video Coding)을 위한 고속 부호화 알고리즘을 제안한다. 제안 방법은 HEVC 의 화면내 부호화 과정에서 주변 부호화 모드 정보인 MPM(Most Probable Mode)과 RMD(Rough Mode Decision) 과정의 결과로 얻어지는 후보 모드들의 상관관계를 이용하여 높은 계산 복잡도를 가지는 RDO(Rate-Distortion Optimization) 과정이 고려하는 후보의 개수를 줄여 전체 부호화기의 부호화 복잡도를 낮춘다. 실험 결과에서는 제안 방법이 약 0.29% BD-rate 의 부호화 손실만으로 20.43%의 부호화 복잡도를 감소시켰음을 보인다.

  • PDF

Fast Mode Decision using Block Size Activity for H.264/AVC (블록 크기 활동도를 이용한 H.264/AVC 부호화 고속 모드 결정)

  • Jung, Bong-Soo;Jeon, Byeung-Woo;Choi, Kwang-Pyo;Oh, Yun-Je
    • Journal of the Institute of Electronics Engineers of Korea SP
    • /
    • v.44 no.2
    • /
    • pp.1-11
    • /
    • 2007
  • H.264/AVC uses variable block sizes to achieve significant coding gain. It has 7 different coding modes having different motion compensation block sizes in Inter slice, and 2 different intra prediction modes in Intra slice. This fine-tuned new coding feature has achieved far more significant coding gain compared with previous video coding standards. However, extremely high computational complexity is required when rate-distortion optimization (RDO) algorithm is used. This computational complexity is a major problem in implementing real-time H.264/AVC encoder on computationally constrained devices. Therefore, there is a clear need for complexity reduction algorithm of H.264/AVC such as fast mode decision. In this paper, we propose a fast mode decision with early $P8\times8$ mode rejection based on block size activity using large block history map (LBHM). Simulation results show that without any meaningful degradation, the proposed method reduces whole encoding time on average by 53%. Also the hybrid usage of the proposed method and the early SKIP mode decision in H.264/AVC reference model reduces whole encoding time by 63% on average.

Down Sampling for Fast Rough Mode Decision for a Hardware-based HEVC Intra-frame encoder (하드웨어 기반 HEVC 인트라 인코더에서 다운 샘플링을 사용한 고속 Rough Mode Decision)

  • Jang, Ji Hun;Rhee, Chae Eun
    • Journal of Broadcast Engineering
    • /
    • v.21 no.3
    • /
    • pp.341-348
    • /
    • 2016
  • HEVC is the next compression standard and is expected to be used widely replacing the conventional H.264/AVC standard. The compression ratio of the HEVC is twice times than H.264/AVC, whereas its computational complexity is increased by up to 40%. Many research efforts have been made to reduce the computational complexity and to speed up encoding. For intra coding, the rough mode decision (RMD) is commonly applied. The rate-distortion optimization (RDO) process to decide the best mode is too complex so that RMD chooses the candidate modes with a simple process and sends the candidates to RDO process. However, for large-size blocks, the RMD also requires considerable computations. In this paper, a down-sampling scheme is proposed for the RMD process. The reference pixel loading, predicted pixel generation are performed using the down-sampled pixel data. When the proposed scheme is applied to the RMD, the computational complexity is reduced by 70% with a marginal bitrate increase of 0.04%. In terms of area of hardware-based RMD, the gate count and the buffer size is reduced 33% and 66%, respectively.

Fast Depth Video Coding with Intra Prediction on VVC

  • Wei, Hongan;Zhou, Binqian;Fang, Ying;Xu, Yiwen;Zhao, Tiesong
    • KSII Transactions on Internet and Information Systems (TIIS)
    • /
    • v.14 no.7
    • /
    • pp.3018-3038
    • /
    • 2020
  • In the stereoscopic or multiview display, the depth video illustrates visual distances between objects and camera. To promote the computational efficiency of depth video encoder, we exploit the intra prediction of depth videos under Versatile Video Coding (VVC) and observe a diverse distribution of intra prediction modes with different coding unit sizes. We propose a hybrid scheme to further boost fast depth video coding. In the first stage, we adaptively predict the HADamard (HAD) costs of intra prediction modes and initialize a candidate list according to the HAD costs. Then, the candidate list is further improved by considering the probability distribution of candidate modes with different CU sizes. Finally, early termination of CU splitting is performed at each CU depth level based on the Bayesian theorem. Our proposed method is incorporated into VVC intra prediction for fast coding of depth videos. Experiments with 7 standard sequences and 4 Quantization parameters (Qps) validate the efficiency of our method.

CU Depth Decision Based on FAST Corner Detection for HEVC Intra Prediction (HEVC 화면 내 예측을 위한 FAST 에지 검출 기반의 CU 분할 방법)

  • Jeon, Seungsu;kim, Namuk;Jeon, Byeungwoo
    • Journal of Broadcast Engineering
    • /
    • v.21 no.4
    • /
    • pp.484-492
    • /
    • 2016
  • The High efficiency video coding (HEVC) is the newest video coding standard that achieves coding efficiency higher than previous video coding standards such as H.264/AVC. In intra prediction, the prediction units (PUs) are derived from a large coding unit (LCU) which is partitioned into smaller coding units (CUs) sizing from 8x8 to 64x64 in a quad-tree structure. As they are divided until having the minimum depth, Optimum CU splitting is selected in RDO (Rate Distortion Optimization) process. In this process, HEVC demands high computational complexity. In this paper, to reduce the complexity of HEVC, we propose a fast CU mode decision (FCDD) for intra prediction by using FAST (Features from Accelerated Segment Test) corner detection. The proposed method reduces computational complexity with 53.73% of the computational time for the intra prediction while coding performance degradation with 0.7% BDBR is small compared to conventional HEVC.

A Frame-based Coding Mode Decision for Temporally Active Video Sequence in Distributed Video Coding (분산비디오부호화에서 동적비디오에 적합한 프레임별 모드 결정)

  • Hoangvan, Xiem;Park, Jong-Bin;Shim, Hiuk-Jae;Jeon, Byeung-Woo
    • Journal of Broadcast Engineering
    • /
    • v.16 no.3
    • /
    • pp.510-519
    • /
    • 2011
  • Intra mode decision is a useful coding tool in Distributed Video Coding (DVC) for improving DVC coding efficiency for video sequences having fast motion. A major limitation associated with the existing intra mode decision methods, however, is that its efficiency highly depends on user-specified thresholds or modeling parameters. This paper proposes an entropy-based method to address this problem. The probabilities of intra and Wyner?Ziv (WZ) modes are determined firstly by examining correlation of pixels in spatial and temporal directions. Based on these probabilities, entropy of the intra and the WZ modes are computed. A comparison based on the entropy values decides a coding mode between intra coding and WZ coding without relying on any user-specified thresholds or modeling parameters. Experimental results show its superior rate-distortion performance of improvements of PSNR up to 2 dB against a conventional Wyner?Ziv coding without intra mode decision. Furthermore, since the proposed method does not require any thresholds or modeling parameters from users, it is very attractive for real life applications.

Fast Intra Mode Decision Method in HEVC (고속 HEVC 부호화기 설계를 위한 화면내 예측 모드 결정 방법)

  • Lee, Sunyoung;Noh, Gyeonggi;Kim, Hyeongduck;Ryoo, Sungul;Shin, Jae-Seob
    • Proceedings of the Korean Society of Broadcast Engineers Conference
    • /
    • /
    • pp.560-563
    • /
    • 2015
  • 동영상 부호화 표준, HEVC(High Efficiency Video Coding)는 부호화 성능을 극대화하기 위해 총 35 개의 화면내 예측 모드를 사용한다. 화면내 예측 모드는 각도를 가진 모드와 각도가 없는 모드로 구성된다. 부호화 성능을 높이기 위해 사용한 다수의 화면내 예측 모드 방법은 HEVC 부호화기의 복잡도를 증대 시키는데 큰 역할을 하게 된다. 본 논문은 총 35 개의 화면내 예측 모드 중 현재 블록의 주변 블록 정보로부터 얻을 수 있는 예측 모드들 및 각도를 대표하는 예측 모드들을 선별적으로 추려서 후보 예측 모드를 결정하고, 평가 과정을 거쳐 해당 후보 모드 중에서 최종 화면내 예측 모드를 결정한다. 본 제안 방법은 35 개의 전체 화면내 예측 모드 중 소수의 후보 모드만을 평가함으로써 HEVC 표준의 화면내 예측 및 부호화 과정의 복잡도를 감소시키려 한다. 제안 방법을 다양한 테스트 시퀀스에 적용한 결과, 35 개 화면내 예측 모드를 전부 사용한 경우와 비교하여 1.1%의 BD-rates 이 증가하면서 18.7%의 부호화기 복잡도를 감소시킬 수 있었다.

  • PDF

Fast Mode Decision for H.264/AVC P Slices Using Classification of SKIP Mode Distortion (SKIP 모드 왜곡의 구분을 통한 H.264/AVC 부호화 P 슬라이스에서의 고속 모드 결정 방법)

  • You, Jong-Min;Jeong, Je-Chang
    • Journal of Broadcast Engineering
    • /
    • v.14 no.1
    • /
    • pp.28-35
    • /
    • 2009
  • H.264/AVC, a recently developed video compression standard, is used for various applications because of its high coding efficiency. Variable block mode plays important role in the high coding efficiency of H.264/AVC but involves significant computations to select the optimal mode. In this paper, a fast mode decision method for H.264/AVC P slices is presented. To reduce computations for mode decision, the proposed mode decision method skips the mode decision processes for small partition modes using distortions of SKIP mode and intra16x16 mode. The experimental results show that the proposed method can reduce encoding time up to 66.41% while maintaining compression efficiency.