• Journal of Information Processing Systems
• /
• v.15 no.3
• /
• pp.492-499
• /
• 2019

HEVC is the high efficiency video coding standard, which provides better coding efficiency contrasted with the other video coding standard. But at the same time the computational complexity increases drastically. Thirty-five kinds of intra-prediction modes are defined in HEVC, while 9 kinds of intra prediction modes are defined in H.264/AVC. This paper proposes a fast rough mode decision (RMD) algorithm which adopts the smoothness of the up-reference pixels and the left-reference pixels to decrease the computational complexity. The three step search method is implemented in RMD process. The experimental results compared with HM13.0 indicate that the proposed algorithm can save 39.7% of the encoding time, while Bjontegaard delta bitrate (BDBR) is increased slightly by 1.35% and Bjontegaard delta peak signal-to-noise ratio (BDPSNR) loss is negligible.

• Journal of Korea Multimedia Society
• /
• v.13 no.2
• /
• pp.185-195
• /
• 2010

In this paper, we propose an efficient inter and intra prediction algorithms for fast encoding of H.264/AVC. First, inter prediction mode decision method decides early using temporal/spatial correlation information and pixel direction information. Second, intra prediction mode decision method selects block size judging smoothness degree with inner/outer pixel value variation and decides prediction mode using representative pixel and reference pixel. Lastly, adaptive motion search region restriction sets search region using mode information of neighboring block and predicted motion vector. The experimental results show that proposed method can achieve about 18~53% reduction compared with the existing JM 14.1 in the encoding time. In RD performance, the proposed method does not cause significant PSNR value losses while increasing bitrates slightly.

• Proceedings of the Korean Society of Broadcast Engineers Conference
• /
• 2009.01a
• /
• pp.170-173
• /
• 2009

In this paper, we propose a fast intra prediction mode selection method in Scalable Video Coding(SVC) which is an emerging video coding standard as an extension of H.264/Advanced Video Coding(H.264/AVC). The proposed method decides a candidate intra prediction mode based on the characteristic of macroblock smoothness. Statistical analysis is applied to computing that smoothness in spatial enhancement layer. We also propose an early termination scheme for Intra_BL mode decision where the RD cost value of Intra_BL is utilized. Compared with JSVM software, our scheme can reduce about 55% of the computation complexity of intra prediction on average, while the performance degradation is negligible; For low QP values, the average PSNR loss is very negligible, equivalently the bit rate increases by 0.01%. For high QP values, the average PSNR loss is less than 0.01dB, which equals to 0.25% increase in bitrate on average.

• Journal of Broadcast Engineering
• /
• v.15 no.3
• /
• pp.380-390
• /
• 2010

The most recent standard video codec, H.264/AVC achieves significant coding efficiency by using a rate-distortion optimization(RDO). The RDO is a measurement for selecting the best mode which minimizes the Lagrangian cost among several modes. As a result, the computational complexity is increased drastically in encoder. In this paper, a method for fast intra prediction mode decision is proposed to reduce the RDO complexity. To speed up Intra$4{\times}4$ and Chroma Intra encoding, the proposed method decides the case that MPM (Most Probable Mode) is the best prediction mode. In this case, the RDO process is skipped, and only MPM is used for encoding the block in Intra$4{\times}4$. And the proposed method is also applied to the chroma Intra prediction mode in a similar way to the Intra$4{\times}4$. The experimental results show that the proposed method achieves an average encoding time saving of about 63% with negligible loss of PSNR (Peak Signal-to-Noise Ratio).

• Journal of information and communication convergence engineering
• /
• v.7 no.2
• /
• pp.193-198
• /
• 2009

The H.264/ AVC video coding standard supports the intra prediction with various block sizes for luma component and a 8x8 block size for chroma components. This new feature of H.264/AVC offers a considerably higher improvement in coding efficiency compared to previous compression standards. In order to achieve this, H.264/AVC uses the Rate-distortion optimization (RDO) technique to select the best intra prediction mode for each block size, and it brings about the drastic increase of the computation complexity of H.264 encoder. In this paper, a fast block size decision algorithm is proposed to reduce the computation complexity of the intra prediction in H.264/AVC. The proposed algorithm computes the smoothness based on AC and DC coefficient energy for macroblocks and compares with the nonparametric criteria which is determined by considering information on neighbor blocks already reconstructed, so that deciding the best probable block size for the intra prediction. Also, the use of non-parametric criteria makes the performance of intra-coding not be dependent on types of video sequences. The experimental results show that the proposed algorithm is able to reduce up to 30% of the whole encoding time with a negligible loss in PSNR and bitrates and provides the stable performance regardless types of video sequences.

• Journal of the Institute of Electronics Engineers of Korea SP
• /
• v.44 no.6
• /
• pp.54-62
• /
• 2007

In this paper, we significantly reduces the amount of computation for intra 16$\times$16 mode decision in H.264 by applying the fast algorithm, which obtains the transformed prediction residual with fewer computations. By extending the existing intra 4$\times$4 mode decision, we propose the new algorithm for fast intra 16$\times$16 mode decision. The proposed algorithm uses partial transform coefficients which consist of one DC and three adjacent AC coefficients after 4$\times$4 transform in the intra 16$\times$16 mode decision. Theoretical analysis and experimental results show that the proposed algorithm can reduce computations up to 50% in the intra 16$\times$16 mode decision process with unnoticeable degradation.

• The Journal of Korean Institute of Communications and Information Sciences
• /
• v.32 no.6C
• /
• pp.585-593
• /
• 2007

For the improvement of coding efficiency, the H.264 standard uses new coding tools such as VBS, 1/4-pel accurate ME, multiple references, intra prediction, loop filter, etc. Using these coding tools, H.264 has achieved significant improvements from rate-distortion point of view compared to existing standards. However, the encoder complexity is greatly increased due to these coding tools. We focus on the complexity reduction method of intra-mode decision. Our algorithm first restricts selective prediction modes of Intra4x4 using a simple preprocessing. The prediction modes of Intra4x4 are used for restricting those of the other inter-modes. Simulation results show that the proposed method outperforms other conventional methods and save about 82% of total encoding time.

• IEMEK Journal of Embedded Systems and Applications
• /
• v.11 no.4
• /
• pp.235-241
• /
• 2016

Compared to the former H.264 standard, the number of the prediction modes has highly increased in HEVC intra prediction. Compression efficiency and accurate prediction are significantly improved. However, the computational complexity increases as well. To solve this problem, this paper proposes the new scheme where not only prediction modes but also block partition candidate are early chosen. Compared to the original intra prediction in HEVC, the proposed scheme achieves about 38% reduction in processing cycles with a marginal loss in compression efficiency.

• Journal of the Institute of Electronics Engineers of Korea SP
• /
• v.41 no.6
• /
• pp.165-173
• /
• 2004

H.264 is the newest international video coding standard that provides high coding efficiency. A macroblock in H.264 has 7 different motion-compensation block sizes in the Inter mode, and several different prediction directions in the Intra mode. In order to achieve as highest coding efficiency as possible, H.264 reference model employs complex mode decision technique based on rate-distortion (RD) optimization which requires high computational complexity. In this paper, we propose two techniques -'early SKIP mode decision' and 'selective intra mode decision' - which can further reduce the computational complexity. Simulation results show that without considerable performance degradation, the proposed methods reduce encoding time by 30% on average and save the number of computing rate-distortion cost by 72%.

• Proceedings of the Korean Society of Broadcast Engineers Conference
• /
• 2013.11a
• /
• pp.71-74
• /
• 2013

차세대 동영상 표준 코덱인 High Efficiency Video Coding(HEVC)은 기존의 AVC/H.264 보다 동일 화질 대비 최대 약 2배의 압축 성능을 보여준다. 이러한 HEVC의 성능을 얻기 위하여 복잡한 연산이 많은 기법이 도입되었고 이로 인하여 HEVC의 시간 복잡도는 AVC/H.264보다 더욱 증가하였다. HEVC의 시간 복잡도를 줄이기 위해서 다양한 고속 알고리즘이 논의되고 있고 인트라 예측 모드에서의 고속 알고리즘 연구 또한 많은 연구가 이루어지고 있다. 본 논문에서는 인트라 예측 모드 결정과정에서 HEVC에 구현된 Rough mode decision(RMD)와 Most probable mode(MPM)의 결과를 활용하여 고속화된 최종예측 모드 결정 방법을 제안한다. 실험 결과, HM 10.0의 All Intra 환경을 기준으로 BD-rate에서 약 0.9%의 손실과 함께 평균 24%의 속도 향상을 얻을 수 있었다.