• Journal of the Institute of Convergence Signal Processing
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• v.1 no.1
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• pp.58-63
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• 2000

This paper describes an efficient algorithm for shot boundary detection in MPEG video stream. There are two types of shot boundary: abrupt and gradual. The proposed algorithm for detecting the abrupt shot boundaries used DCT DC value in compressed domain. The proposed algorithm of the gradual change detection consists of two-pass mechanism. In the first pass, the expected positions of shot boundaries are extracted using ratio value of motion vectors. After decoding frames that are extracted in the first pass, we will make the dissolving image using (n)th and (n+2)th image of expected position. The gradual shot boundaries are selected by similarity of the dissolving image and the image of (n+1)th expected position. As applying the algorithm for detecting shot boundaries, the gradual changes as well as the abrupt changes are detected efficiently. Experimental results indicate that the proposed method is computationally fast for detecting shot boundaries and robust to the variation of the video characteristic that is different for the kind of videos.

• Journal of Broadcast Engineering
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• v.8 no.1
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• pp.72-79
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• 2003

The Eureka-147 Digital Audio Broadcasting(DAB) system is the new international standard for mobile broadcasting services including high-quality audio, program associated data and other multimedia data. In this paper, we design the transport frame structures for the mobile multimedia services by using the configuration of the Eureka-147 DAB multiplex and MPEG system specifications, and then compare their performances in terms of functionality and overhead. Especially, we suggest and analyze the effective transport structures, which are improved in the efficiency of media multiplexing architecture, by removing the functionally overlapped parts between DAB and MPEG systems. In addition, we evaluate the transmission environments of various DAB data channels and demonstrate the transmission error effects on the low bit rate video stream.

• Journal of Satellite, Information and Communications
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• v.9 no.4
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• pp.38-41
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• 2014

Due to the diversity of device performances and the possibility of providing multimedia service through many networks, media consumption environment has been changed in various ways. In recent, mobile services and broadcasting services started to provided through IP network. According to this flow changes, there was great demand for various multimedia services through heterogenous networks. To solve this problem, MMT was suggested as a standard of multimedia transport which replaces MPEG-2 TS(Transport Stream) which is used for HD(High Definition) transport. MMT can be provided various broadcasting based on IP through terrestrial, satellite, cable broadcasting networks, and also deliver multimedia through many networks at the same time. MMT was risen as a method of servicing UHD broadcasting. In this paper, we present an implementation of service architecture for hierarchical UHD broadcasting over heterogenous networks using MMT.

• Journal of the Institute of Electronics Engineers of Korea SP
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• v.42 no.5 s.305
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• pp.29-40
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• 2005

According as base of digital hologram has been magnified, discussion of compression technology is expected as a international standard which defines the compression technique of 3D image and video has been progressed in form of 3DAV which is a part of MPEG. As we can identify in case of 3DAV, the coding technique has high possibility to be formed into the hybrid type which is a merged, refined, or mixid with the various previous technique. Therefore, we wish to present the relationship between various image/video coding techniques and digital hologram In this paper, we propose an efficient coding method of digital hologram using standard compression tools for video and image. At first, we convert fringe patterns into video data using a principle of CGH(Computer Generated Hologram), and then encode it. In this research, we propose a compression algorithm is made up of various method such as pre-processing for transform, local segmentation with global information of object image, frequency transform for coding, scanning to make fringe to video stream, classification of coefficients, and hybrid video coding. Finally the proposed hybrid compression algorithm is all of these methods. The tool for still image coding is JPEG2000, and the toots for video coding include various international compression algorithm such as MPEG-2, MPEG-4, and H.264 and various lossless compression algorithm. The proposed algorithm illustrated that it have better properties for reconstruction than the previous researches on far greater compression rate above from four times to eight times as much. Therefore we expect that the proposed technique for digital hologram coding is to be a good preceding research.

• Journal of Broadcast Engineering
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• v.10 no.4 s.29
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• pp.474-487
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• 2005

T-DMB (Terrestrial-Digital Multimedia Broadcasting) adopted MPEG-4 BIFS (Binary Format for Scene) Core2D scene description profile and graphics profile as the standard of video associated data service. By using BIFS, we can support to overlay objects, i.e. text, stationary image, circle, polygon, etc., on the main display of receiving end according to the properties designated in broadcasting side and to make clickable buttons and website links on desired objects. Therefore, a variety of interactive data services can be served by BIFS. In this paper, we implement real-time video associated data service system far T-DMB. Our developing system places emphasis on real-time data service by user operation and on inter-working and stability with our previously developed video encoder. Our system consists of BIFS Real-time System, Automatic Stream Control System and Receiving Monitoring System. Basic functions of our system are designed to reflect T-DMB programs and characteristics of program production environment as a top priority. Our developed system was used in BIFS trial service via KBS T-DMB, it is supposed to be used in T-DMB main service after improvement process such as intensifying system stability.

• Journal of the Institute of Electronics Engineers of Korea SD
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• v.45 no.11
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• pp.71-76
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• 2008

H.264(or MPEG-4/AVC pt.10) is a high performance video coding standard, and is widely used. Variable length code (VLC) of the H.264 standard compresses data using the statistical distribution of values. A decoder parses the compressed bit stream and searches decoded values in lookup tables, and the decoding process is not easy to implement by hardware. We propose an architecture of variable length decoder(VLD) for the H.264 baseline profile(BP) L4. The CAVLD decodes syntax elements using the combination of arithmetic units and lookup tables for the optimized hardware architecture. A barral shifter and a first 1's detector parse NAL bit stream, and are shared by Exp-Golomb decoder and CAVLD. A FIFO memory between CAVLD and the reorder unit and a buffer at the output of the reorder unit eliminate the bottleneck of data stream. The proposed VLD is designed using Verilog-HDL and is implemented using an FPGA. The synthesis result using a 0.18um standard CMOS technology shows that the gate count is 22,604 and the decoder can process HD($1920{\times}1080$) video at 120MHz.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.28 no.9A
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• pp.746-753
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• 2003

In this paper, we propose an efficient algorithm for non-streaming synchronized data processing based on ATSC-DASE in terrestrial digital data broadcasting services. Non-streaming synchronized data is encapsulated in DSM-CC sections with PTS(presentation time stamp) values associated with A/V and it is transmitted in a form of MPEG-2 TS(transport stream). At the receiver, the transmitted A/V data are processed by PC based set-top box(STB) in real-time, and the transmitted non-streaming synchronized data is also stored at the STB and is displayed at right time by the proposed algorithm. To verity the proper operation of the proposed algorithm, we make a scenario for non-streaming synchronized data by XML, and finally we are able to display it properly by using declarative application(DA) browser.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.31 no.4A
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• pp.421-430
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• 2006

In this paper, we propose a practical implementation of network-adaptive HD(high definition) MPEG-2 video streaming with a cross-layered channel monitoring(CLM) over the IEEE 802.11a WLAN(wireless local area network). For wireless channel monitoring, AP(access point) periodically measures the MAC(medium access control) layer transmission information and sends the monitoring information to a streaming server. This makes that the streaming server reacts more quickly as well as efficiently to the fluctuated wireless channel than that of the end-to-end monitoring(E2EM) scheme for the video adaptation. The streaming sewer dynamically performs the priority-based frame dropping to adjust the video sending rate according to the measured wireless channel condition. For this purpose, our streaming system nicely provides frame-based prioritized packetization by using a real-time stream parsing module. Various evaluation results over an IEEE 802.11a WLAM testbed are provided to verify the intended QoS adaptation capability The experimental results show that the proposed system can effectively mitigate the quality degradation of video streaming caused by the fluctuations of time-varying wireless channel condition.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.10 no.4
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• pp.1944-1956
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• 2016

The Digital Video Broadcasting-Common Scrambling Algorithm is an ETSI-designated algorithm designed for protecting MPEG-2 signal streams, and it is universally used. Its structure is a typical hybrid symmetric cipher which contains stream part and block part within a symmetric cipher, although the entropy is 64 bits, there haven't any effective cryptanalytic results up to now. This paper studies the security level of CSA against impossible differential cryptanalysis, a 20-round impossible differential for the block cipher part is proposed and a flaw in the cipher structure is revealed. When we attack the block cipher part alone, to recover 16 bits of the initial key, the data complexity of the attack is O(2^44.5), computational complexity is O(2^22.7) and memory complexity is O(2^10.5) when we attack CSA-BC reduced to 21 rounds. According to the structure flaw, an attack on CSA with block cipher part reduced to 21 rounds is proposed, the computational complexity is O(2^21.7), data complexity is O(2^43.5) and memory complexity is O(2^10.5), we can recover 8 bits of the key accordingly. Taking both the block cipher part and stream cipher part of CSA into consideration, it is currently the best result on CSA which is accessible as far as we know.

• Proceedings of the IEEK Conference
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• 2003.07e
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• pp.1956-1959
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• 2003

본 논문에서는 HDTV(High Definition TV) 방송수신을 위한 DSP(Digital Signal Processor)기반의 HD급 비디오/오디오 디코더 시스템을 개발하고 그 성능을 확인하였다. DSP 플랫폼은 TI(Texas Instrument)사의 TMS320C6415를 대상으로 하였으며 TI의 DSP RTOS인 DSP/ BIOS를 이용하여 방송스트림인 TS(Transport Stream)을 분리하기 위한 TS Demuxer, MPEG-2 비디오 디코더 및 AC-3 오디오디코더 알고리즘을 통합하였으며, 각각의 알고리즘은 대상 DSP플랫폼인 TMS320C64x에 맞게 고정소수점 구조화 및 최적화를 실시하였다. 테스트를 위한 시스템은 스트리밍을 위한 호스트 PC와 PCI(Peripheral Component Interconnect)버스를 통해 연결된 DSP보드로 구성하였으며 실제 HDTV당송용 스트림과 SD(Standard Definition)급 스트림을 이용하여 성능을 확인하였다.