• Journal of Broadcast Engineering
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• v.11 no.3 s.32
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• pp.363-378
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• 2006

The Digital Multimedia Broadcasting(DMB) system is developed to offer high quality audio-visual multimedia contents to the mobile environment. The system adopts MPEG-4 standard for the main video, audio and other media format. It also adopts the MPEG-4 scene description for interactive multimedia contents. The animated and interactive contents can be actualized by BIFS(Binary Format for Scene), the binary format for scene description that refers to the spatio-temporal specifications and behaviors of the individual objects. As more interactive contents are, the scene description is also needed more high bitrate. However, the bandwidth for allocating meta data such as scene description is restrictive in mobile environment. On one hand, the DMB terminal starts demultiplexing content and decodes individual media by its own decoder. After decoding each media, rendering module presents each media stream according to the scene description. Thus the BIFS stream corresponding to the scene description should be decoded and parsed in advance of presenting media data. With these reason, the transmission delay of BIFS stream causes the delay of whole audio-visual scene presentation although the audio or video streams are encoded in very low bitrate. This paper presents the effective optimization technique for adapting BIFS stream into expected MPEG-2 TS bitrate without any bandwidth waste and avoiding the transmission delay of the initial scene description for interactive DMB contents.

• Journal of Internet Computing and Services
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• v.17 no.4
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• pp.11-17
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• 2016

In this paper, we proposed a multi-viewer system with multiple HD cameras based AVB(Audio Video Bridge) ethernet cable using IP networking, and FPGA(Xilinx Zynq 702) for bus safety systems. This AVB (IEEE802.1BA) system can be designed for the low latency based on FPGA, and transmit real-time with HD video and audio signals in a vehicle network. The proposed multi-viewer platform can multiplex H.264 video signals from 4 wide-angle HD cameras with existed ethernet 1Gbps. and 2-wire 100Mbps cables. The design of Zynq 702 based low latency to H.264 AVC CODEC was proposed for the minimization of time-delay in the HD video transmission of car area network, too. And the performance of PSNR(Peak Signal-to-noise-ratio) was analyzed with the reference model JM for encoding and decoding results in H.264 AVC CODEC. These PSNR values can be confirmed according the theoretical and HW result from the signal of H.264 AVC CODEC based on Zynq 702 the multi-viewer with multiple cameras. As a result, proposed AVB multi-viewer platform with multiple cameras can be used for the surveillance of audio and video around a bus for the safety due to the low latency of H.264 AVC CODEC design.

• Proceedings of the Korean Society of Broadcast Engineers Conference
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• 2010.11a
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• pp.119-124
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• 2010

디지털 제작, 압축 기술의 발전, 유무선 인터넷 보급 확산, 다양한 전송 및 서비스 플랫폼의 등장, 전송 기술의 광대역화, 단말 기술의 발전, 라이프스타일 변화와 킬러 서비스 등장으로 미디어 시장은 급속도로 발전하고 있다. 지상파 방송은 아날로그에서 디지털로 전환하고 있으며, 고화질, 다채널, 모바일, 3D 서비스를 제공하거나 제공할 예정에 있다. 현재 디지털 TV는 아날로그 TV와 동시 방송 형태로 제공되고 있지만 2012년말 디지털 TV로 완전한 전환을 앞두고 있으며, 모바일 TV인 DMB는 2005년말 본방송을 시작하여 전국 서비스를 제공하고 방송 커버리지를 확장하고 있다. FM과 AM의 디지털화를 위한 디지털 오디오 방송도 방식 선정을 위한 절차가 진행 중이다. 전파는 송신소에서 단말까지 전송되는 도중 신호레벨 감쇠, 페이딩, 왜곡, 잡음 유입 등을 겪게 된다. 양질의 지상파 방송을 제공하기 위해서는 전파가 수신 가능한 상태 이상의 양호한 상태로 시청자에게 전달되어야 한다. 이를 위해 방송사는 방송 수신 품질을 측정하고 수신이 불량한 지역에 대해서는 송신기 설치, 송신 출력 증강, 중계기 설치 등을 통해 양질의 서비스 제공이 가능한 방송 서비스 영역을 확대한다. 다양한 지상파 방송 매체에서 수신 품질 평가를 위해 가장 많이 측정하는 항목은 전계강도이다. 대부분의 경우 어떤 지역의 전계강도가 해당 매체가 요구하는 기준 레벨 이상이면 해당 지역을 양호 지역으로 평가한다. 본 논문에서는 다양한 지상파 방송 매체에 대한 전계강도를 측정하고 이를 분석할 수 있는 시스템을 제안하고자 한다. 제안 시스템을 이용하면 자동화된 절차에 의해 최단 시간에 다양한 지역에 대한 방송 수신 품질을 측정하고, 그 결과를 분석하여 방송 서비스 영역에 대한 평가를 내릴 수 있으며, 측정결과를 DB로 관리하여 동일 채널에 대한 이전 측정결과와 비교 분석, 다른 채널과 전계강도 비교 분석을 통해 특정 송신기 출력이 감소되거나 특정 안테나 출력에 문제가 발생한 경우에도 이를 쉽게 감지하여 최적의 방송망 구축 및 관리가 가능하다.

• Journal of the Institute of Electronics Engineers of Korea SD
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• v.42 no.4 s.334
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• pp.61-68
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• 2005

A chip, which can fast encoder the audio data to AAC (Advanced Audio Coding) LC(Low Complexity) that is MPEG-2 audio standard, has been designed on the basis of a 32 bits DSP core and fabricated with 0.25um CMOS technology. At first, the various optimization methods for implementing the algerian are devised to reduce the memory size and calculation cycles. FFT(Fast Fourier Transform) hardware block is added to the DSP core to get the more reduction of the calculation cycles. The chips has the size of $7.20\times7.20 mm^2$ and about 830,000 equivalent gates, can carry out AAC encoding under 70MIPS(Million Instructions per Second).

• Journal of Broadcast Engineering
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• v.21 no.3
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• pp.330-340
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• 2016

This paper explains about the structure of multiple sensorial media application format (ISO/IEC 23000-17), which is newly standardized as a project of MPEG-A. This format facilitates effective storage, playing, and management of media with multiple sensorial effects. The ISO base media file format from MPEG-4 Part 12 and sensory effect metadata (SEM) from MPEG-V Part 3 are used to composed the multiple sensorial media application format. In this paper, a fragmentation method to break a SEM XML document into valid SEM samples is presented. Several binarization methods to compress the SEM samples are compared and evaluated as well. The compression ratio and processing time using the MPEG-V binary representation and the Binary MPEG format for XML (BiM) are superior to the gzip compression.

• Journal of Broadcast Engineering
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• v.21 no.3
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• pp.436-449
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• 2016

This paper compares the transport overhead of MMT (MPEG Media Transport) with that of MPEG-2 TS (Transport Stream). MPEG-2 TS is globally used in multiplexing compressed audio and video data in digital broadcast industry, including areas of DTV (Digital Television), IPTV (Internet Protocol Television), and DMB (Digital Multimedia Broadcasting). It was the early 1990s when MPEG-2 TS standard was established. After more than two decades of years since its first establishment, many parts of MPEG-2 TS turned out to be inappropriate to today's broadcast and communication environment. Given the situations, in 2014 MPEG (ISO/IEC JTC 1 SC 29/WG 11) standardized MMT as the next-generation multimedia transport standard hopefully that can replace MPEG-2 TS. In this paper, with assumptions of broadcast service scenarios we applied both MMT and MPEG-2 TS to each scenario and we calculated their transport overheads. We used a software program that counts the transport overhead, which was developed in our laboratory for this paper. And we conducted a comparative analysis based on the calculated result of transport overhead.

• The Transactions of the Korea Information Processing Society
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• v.7 no.12
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• pp.3885-3895
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• 2000

The emergence of digital imaging and digital networks has made duplication of original artwork easier. In order to protect these creations, new methods for signing and copyrighting visual data are needed. In the last few years, a large number of schemes have heen proposed for hiding copyright marks and other information in digital image, video, audio and other multimedia objects. In this paper, we propose a technique for embedding the watermark of visually recognizable patterns into the frequency domain of images. The embedded watermark can be retrieved from the decoded sequence witbout knowledge of the original. Because the source image is not required to extract the watermark, one cannot make the fake original that is invertible to watermarking scheme from the waternlarked image. In order to recover the embedded signature data without knowledge of the original, a prediction of the original value of the pixel containing the information is needed. The prediction is based on a averaging of amplitude values in a neighborhood around the pixel itself. Additionally the projxJsed technique could survive several kinds of image processings including JPEG lossy compression.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.4 no.5
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• pp.1051-1066
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• 2000

According to the recent advances of digital encoding technologies and computing power, large amounts of multimedia informations such as image, graphic, audio and video are fully used in multimedia systems through Internet. By this, diverse retrieval mechanisms are required for users to search dedicated informations stored in multimedia systems, and especially it is preferred to use contents-based retrieval method rather than text-type keyword retrieval method. In this paper, we propose a new contents-based indexing and searching algorithm which aims to get both high efficiency and high retrieval performance. To achieve these objectives, firstly the proposed algorithm classifies images by a pre-processing process of edge extraction, range division, and multiple filtering, and secondly it searches the target images using spatial and textural characteristics of colors, which are extracted from the previous process, in a image. In addition, we describe the simulation results of search requests and retrieval outputs for several images of company's trade-mark using the proposed contents-based retrieval algorithm based on wavelet.

• The Transactions of the Korea Information Processing Society
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• v.6 no.4
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• pp.1112-1119
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• 1999

Digital watermarking is to embed imperceptible mark into image, video, audio and text data to prevent the illegal copy of multimedia data, arbitrary modification, and also illegal sales of the copes without agreement of copyright ownership. The DCT(discrete Cosine Transforms) transforms of original image is conducted in this research and these DCT coefficients are expanded by Fourier series expansion algorithm. In order to embed the imperceptible and robust watermark, the Fourier coefficients(lower frequency coefficients) can be calculated using sine and cosine function which have a complete orthogonal basis function, and the watermark is embedded into these coefficients, In the experiment, we can show robustness with respect to image distortion such as JPEG compression, bluring and adding uniform noise. The correlation coefficient are in the range from 0.5467 to 0.9507.

• The KIPS Transactions:PartB
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• v.8B no.5
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• pp.579-586
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• 2001

Digital watermarking is to embed imperceptible mark into image, video, audio, and text data to prevent the illegal copy of multimedia data. arbitrary modification, and also illegal sales of the copies without agreement of copyright ownership. In this paper, we study for the embedding and extraction of watermark key using wavelet in the luminance signal in order to implement the system to protect the copyright for image MPEG. First, the original image is analyzed into frequency domain by discrete wavelet transform. The RSA(Rivest, Shamir, Aldeman) public key of the coded target is RUN parameter of VLD(variable length coding). Because the high relationship among the adjacent RUN parameters effect the whole image, it prevents non-authorizer not to possess private key from behaving illegally. The Results show that the proposed method provides better moving picture and the distortion more key of insert than direct coded method on low-frequency domain based DCT.