Bongsoo Jung - Academia.edu (original) (raw)

Papers by Bongsoo Jung

We propose atranscoding schemeforconverting B toP slices intheH.264videocoding standard without s... more We propose atranscoding schemeforconverting B toP slices intheH.264videocoding standard without spatial resolution change. Whenareceiver suchasportable player of baseline profile wantstoshowcontents ofmainprofile encoded inthebi-predictive mode,itisdesirable toconvert B toP slices instead ofjustdiscarding theB slices. Theproposed scheme makesuseofmotionvectoranditsrefinement. To utilize previous coding modesandresidual data, wedevelop twomode decision methods ofprobability-based andneighbor mode-based ones.Theexperiment results showsthattheproposed method speeds upbyapproximately 54-68%whileminimizing quality distortion, ascompared tofully re-encoding method. Keywords - Transcoding, Bslices, H.264, BDVS

Advanced Communication Technology International Conference, 2007

The H.264/AVC standard substantially improved its coding efficiency and subjective quality by usi... more The H.264/AVC standard substantially improved its coding efficiency and subjective quality by using the intra prediction technique and the adaptive coding between inter and intra modes based on rate-distortion optimization. This encoding scheme, however, increases encoding complexity dramatically and causes troubles in its practical applications in the real-time mobile environment. In order to decrease the complexity, various methods are proposed

Journal of the Institute of Electronics Engineers of Korea, 2007

H.264/AVC uses variable block sizes to achieve significant coding gain. It has 7 different coding... more 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 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 hy...

Recent proliferation of portable devices requires video contents playable on virtually any portab... more Recent proliferation of portable devices requires video contents playable on virtually any portable devices. However, their limited computing resources pose significant restriction to accomplish real-time decoding of high resolution or high quality video contents. To solve the problem, we propose a complexity scalable video decoding scheme for realtime playback on portable devices. In this paper, we analyze the complexity of H.264/AVC video decoding elements and develop a complexity scalable decoding scheme by simplifying motion compensation and deblocking filtering. Experimental results with the H.264/AVC main profile coded bitstream show that its decoding complexity can be reduced up to 26% without significant loss in subjective quality as compared to the conventional H.264/AVC decoder. Keywords-H.264/AVC; video decoder; complexity scalable decoding

Journal of Broadcast Engineering, 2009

The conventional video compression standard of H.264 uses four different prediction modes in B pi... more The conventional video compression standard of H.264 uses four different prediction modes in B pictures, namely, forward, backward, direct, and bi-predictive predictions. The bi-directional prediction mode is a special case of the bi-prediction which employs two reference frames, one from the forward and the other from the backward pictures. The recent Audio-Video Standard (AVS) of China employed a new bi-prediction mode, namely, the symmetric mode under which only a single forward motion vector is coded. The missing backward motion vector is derived from the forward motion vector using temporal distance between forward/backward reference frames to and from the current B picture. However, the technique has a limit in that it can only take advantage of forward motion vector even though the accuracy of forward prediction may be worse than that of the backward one. In this paper, we propose an improved symmetric mode by exploiting not only the symmetric mode with forward motion vector coding but also the symmetric mode with backward motion vector coding.

Battery-powered devices has recently become a prevalent platform for which video compression is o... more Battery-powered devices has recently become a prevalent platform for which video compression is one of the most important enabling technologies. The H.264/AVC employs many advanced coding tools for high coding efficiency, however, it requires high computational complexity and high energy consumption. It is a major problem in batterypowered devices. In this paper, we analyze power consumption charactersitic of H.264/AVC video encoding tools using the modified simpleScalar and the Sim- Panalyzer.

APCCAS 2008 - 2008 IEEE Asia Pacific Conference on Circuits and Systems, 2008

In this paper, we propose a pooled zero vector coding scheme for improving coding efficiency of m... more In this paper, we propose a pooled zero vector coding scheme for improving coding efficiency of moving pictures. Since motion vector takes considerable portion of compressed bitstream, its higher compression is very essential for improving the coding efficiency of moving pictures beyond that given by the state-of-the-art coder of H.264/AVC. Since there is considerable correlation among motion vectors of adjacent

2004 IEEE International Conference on Multimedia and Expo (ICME) (IEEE Cat. No.04TH8763), 2004

This paper presents a selective temporal error concealment algorithm (STEC) for error-corrupted H... more This paper presents a selective temporal error concealment algorithm (STEC) for error-corrupted H.264/AVC video bitstreams over CDMA2000 (or UMTS) air interface. The proposed algorithm performs selective temporal error concealment depending on whether a lost MB is at background or foreground. It is shown that under FMO coding mode of H.264/AVC, the proposed algorithm provides PSNR gain up to 1.18dB compared to built-in algorithm in the H.264/AVC test model. In addition, the proposed STEC has average PSNR improvement of 0.33dB compared with that under N slice coding mode.

Visual Communications and Image Processing 2003, 2003

Recent advances in video coding technology have resulted in rapid growth of application in mobile... more Recent advances in video coding technology have resulted in rapid growth of application in mobile communication. With this explosive growth, reliable transmission and error resilient technique become increasingly necessary to offer high quality multimedia service. This paper discusses the error resilient performances of the MPEG-4 simple profile under the H.324/M and the H.264 baseline under the IP packet networks. MPEG-4 simple profile has error resilient tools such as resynchronization marker insertion, data partitioning, and reversible VLC. H.264 baseline has the flexible macroblock ordering scheme, and others. The objective and subjective quality of decoded video is measured under various random bit and burst error conditions. Keywords: Error resilient tools, MPEG-4, H.264, video coding technology

Proceedings of the 7th International Conference on Advances in Mobile Computing and Multimedia - MoMM '09, 2009

The new video coding paradigm based on the Slepian-Wolf and Wyner-Ziv theorems, namely, Distribut... more The new video coding paradigm based on the Slepian-Wolf and Wyner-Ziv theorems, namely, Distributed Video Coding (DVC) is being actively studied as a light-weighted video encoding technique. The Wyner-Ziv coding scheme being the most representative DVC algorithm reconstructs an image by eliminating noises on side information using channel code. The quality of side information is an essential factor to achieve

The 9th International Conference on Advanced Communication Technology, 2007

ABSTRACT

Multimedia Systems and Applications VIII, 2005

Most of fast block motion estimation algorithms reported so far in literatures aim to reduce the ... more Most of fast block motion estimation algorithms reported so far in literatures aim to reduce the computation in terms of the number of search points, thus do not fit well with multimedia processors due to their irregular data flow. For multimedia processors, proper reuse of data is more important than reducing number of absolute difference operations because the execution cycle