• 전자공학회논문지 IE
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• v.47 no.2
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• pp.21-26
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• 2010

This paper proposed an efficient algorithm to reduce the amount of calculation for Scalability Extension which takes a great deal of the operational time in H.264/AVC. This algorithm decides a search range according to the direction of predicted motion vector, and then performs an adaptive spiral search for the candidates with JM(Joint Model) FME(Fast Motion Estimation) which employs the rate-distortion optimization(RDO) method. Experimental results by applying the proposed method to various video sequences showed that the process time was decreased up to 80% comparing to the previous prediction methods. The degradation of video Quality was only from 0.05dB to 0.19dB and the compression ratio decreased as small as 0.58% in average. Therefore, we are sure that the proposed method is an efficient method for the fast inter prediction.

• 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.

• Journal of the Korea Computer Industry Society
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• v.6 no.5
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• pp.801-812
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• 2005

H.264/AVC is the international video coding standard which has significant improvements of coding efficiency. ITU-T(International Telecommunication Union-Telecommunication standardization sector) and MPEG(Moving Picture Experts Group) adopts various complex coding tool such as variable block size motion, multiple reference frames, quarter-pel motion estimation/compensation (ME/MC) and rate-distortion(RD) optimization, etc. H.264 reference model employs complex mode decision technique based on RD optimization which requires high computational complexity. In this paper, we propose an efficient coding mode decision based on the cost distribution of RD in the macroblock coding mode sequence. Simulation results show that the proposed method reduces encoding time by 34% on average and save the number of computing RD cost by 82%.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.32 no.8C
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• pp.729-737
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• 2007

The H.264/AVC video coding standard provides higher coding efficiency compared to the conventional MPEG-2 standard. Since a lot of videos have been encoded using MPEG-2, the format conversion from MPEG-2 to H.264 is essential. In this paper, we propose an efficient method for the conversion of DCT coefficients to H.264/AVC transform coefficients. This conversion is essential, since $8{\times}8$ DCT and $4{\times}4$ integer transform are used in MPEG-2 and H.264/AVC, respectively. The mathematical analysis and computer simulation show that the computational complexity of the proposed algorithm is reduced compared to the conventional algorithm, while the loss caused by the conversion is negligible.

• Journal of Broadcast Engineering
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• v.15 no.4
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• pp.513-526
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• 2010

In this paper, we propose a de-blocking filter for improvement of coding efficiency and computational complexity reduction on a high definition video coding. Recently, the H.264/AVC standard-based research for high definition video coding method is under way because the amount of used of high definition videos is on the increase. The H.264/AVC de-blocking filter is designed for low bitrate video coding and it improves not only the subjective quality but also coding efficiency by minimizing the blocking artifact. However, the H.264/AVC de-blocking filter that strong filtering is performed is not suitable in a high definition video coding which occurs relatively low blocking artifact. Also, the conventional de-blocking filter has high computational complexity in decoder side. The computational complexity of the proposed method is reduced about maximum 8.8% than conventional method. Furthermore, the coding efficiency of the proposed method is about maximum 7.3% better than H.264/AVC de-blocking filter.

• IEIE Transactions on Smart Processing and Computing
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• v.2 no.2
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• pp.86-96
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• 2013

VP8, an open web media video format, has recently attractedmuch attention, particularly from major web browser companies, as a video codec for HTML5 on internet due to its good coding efficiency and royalty-free policy. Compared to other video compression schemes such as H.264/AVC, it has several distinctive coding tools that help to ensure good coding efficiency and low decoding complexity. In this paper, we investigate its coding techniques and analyze its rate-distortion (R-D) coding performance as compared to that of H.264/AVC.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.39C no.6
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• pp.503-511
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• 2014

In this paper, a novel, real-time video stitching algorithm in an H.264/AVC compressed domain is proposed. This enables viewers to watch multiple video contents using a single device. The basic concept of this paper is that the server is asked to combine multiple streams into one bit-stream based in a compressed domain. In other words, this paper presents a new compressed domain combiner that works in boundary macroblocks of input videos with re-calculating intra prediction mode, intra prediction MVD, a re-allocation of the coefficient table, and border extension methods. The rest of the macroblocks of the input video data are achieved simply by copying them. Simulation experiments have demonstrated the possibility and effectiveness of the proposed algorithm by showing that it is able to generate more than 103 frames per second, stitching four 480p-sized images into each frame.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2009.10a
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• pp.193-195
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• 2009

Bluetooth is a popluar wireless data transmission method with low power consumption. In this paper, we present a open source based player of video stream encoded by H.264 codec, which is transmitted via Bluetooth. An open source JM is used for H.264 decoding and modified for reading H.264 encoded data via Bluetooth. For display of decoded video data, SDL was utilized.

• Journal of the Institute of Electronics Engineers of Korea SP
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• v.45 no.5
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• pp.79-86
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• 2008

H.264/AVC is the newest international video coding standard developed by the joint ITU-T and ISO/IEC standards organizations. This newest video coding standard offers much higher coding efficiency than the H.261, H.263 and MPEG-4. But it has high computing complexity and high H/W resources wasting problem. This paper described the two unit parallel pipeline structure. This new structure comparing with standard model decreased the computing complexity of 67% and the H/W resources waste of 3%.

• The KIPS Transactions:PartB
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• v.13B no.3 s.106
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• pp.245-254
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• 2006

In this work, a new rate control algorithm for transmission of H.264/AVC video bit stream through CBR(constant bit rate) channel is proposed. The proposed algorithm predicts target bit rate and MAD(mean of absolute difference) for current frame considering image complexity variance between neighboring backward and current images. In details, respective linear regression analysis for MAD and encoded bit rate against image complexity variance produce correlation parameters. Additionally, it uses frame skip technique to maintain bit stream within a manageable range and protect buffer from overflow or underflow. Implementation and experimental results show that the proposed algorithm can provide accurate bit allocation, and can effectively visual degradation after scene changes. Also our proposed algorithm encodes the video sequences with less frame skipping compared to the existing rate control for H.264/AVC.