• Proceedings of the IEEK Conference
• /
• 2000.09a
• /
• pp.775-778
• /
• 2000

2채널의 MPEG-2 Layer-Ⅲ 오디오 복호화 알고리듬이 16비트의 고정소수점 연산기로도 고음질의 오디오출력을 얻을 수 있도록 최적화를 수행하였다. 고음질을 얻기 위하여 고정소수점 연산기에서 발생하는 양자화 오차를 최소화 하였으며 각 복호화 과정 별로 최소의 오차를 발생시키는 알고리듬을 제안하고 사용하였다. 고정소수점 모의실험은 C-언어를 사용하여 수행되었으며, ISO-IEC 13818-4 Compliance Test를 수행하여 최적화된 복호화기가 ISO／IEC 13818-4 audio decoder의 기준을 만족함을 보였다.

• Journal of the Institute of Electronics Engineers of Korea TE
• /
• v.39 no.4
• /
• pp.355-355
• /
• 2002

In this paper, we designed a FPU(floating point unit) that it is very important and requires of high density when digital audio is designed. Almost audio system must support the multi-channel and required for high quality. A floating point arithmetic function in MPEG-2 AAC that implemented by hardware is able to realtime decoding when DSP realization. The reason is that MPEG-2 AAC is compatible to the Audio field of MPEG-4 and afterwards. We designed a FPU by hardware to increase the speed of a floating point unit with much calculation part in the MPEG-2 AAC Decoder. A FPU is composed of a multiplier and an adder. A multiplier used the Radix-4 Booth algorithm and an adder adopted 1's complement method for speed up. A form of a floating point unit has 8bit of exponent part and 24bit of mantissa. It's compatible with the IEEE single precision format and adopted a pipeline architecture to increase the speed of a processor. All of sub blocks are based on ISO/IEC 13818-7 standard. The algorithm is tested by C language and the design does by use of VHDL(VHSIC Hardware Description Language). The maximum operation speed is 23.2MHz and the stable operation speed is 19MHz.

• The Journal of the Acoustical Society of Korea
• /
• v.21 no.3
• /
• pp.237-244
• /
• 2002

In this paper we mention the optimization of MPEG-4 VM (Moving Picture Expert Group-4 Verification Model) GA (General Audio) AAC (Advanced Audio Coding) encoder and the design of the decoder for PDA (Personal Digital Assistant) using MPEG-4 VM source. We profiled the VMC source and several optimization methods have applied to those selected functions from the profiling. Intel Pentium III 600 MHz PC, which uses windows 98 as OS, takes about 20 times of encoding time compared to input sample running time, with additional options, and about 10 times without any option. Decoding time on PDA was over 35 seconds for the 17 seconds input sample. After optimization, the encoding time has reduced to 50% and the real time decoding has achieved on PDA.

• The Journal of Korean Institute of Communications and Information Sciences
• /
• v.42 no.2
• /
• pp.432-443
• /
• 2017

The primary goal of the MPEG-H 3D Audio standard is to provide immersive audio environments for high-resolution broadcasting services such as UHDTV. This standard incorporates a wide range of technologies such as encoding/decoding technology for multi-channel/object/scene-based signal, rendering technology for providing 3D audio in various playback environments, and post-processing technology. The reference software decoder of this standard is a structure combining several modules and can operate in various modes. Each module is composed of independent executable files and executed sequentially, real time decoding is impossible. In this paper, we make DLL library of the core decoder, format converter, object renderer, and binaural renderer of the standard and integrate them to enable frame-based decoding. In addition, by measuring the computation complexity of each mode of the MPEG-H 3D-Audio decoder, this paper also provides a reference for selecting the appropriate decoding mode for various hardware platforms. As a result of the computational complexity measurement, the low complexity profiles included in Korean broadcasting standard has a computation complexity of 2.8 times to 12.4 times that of the QMF synthesis operation in case of rendering as a channel signals, and it has a computation complexity of 4.1 times to 15.3 times of the QMF synthesis operation in case of rendering as a binaural signals.

• Broadcasting and Media Magazine
• /
• v.4 no.1
• /
• pp.62-79
• /
• 1999

In this survey paper the emerging MPEG-4 audio technology is discribed In the previous MPEG-1 and the MPEG-4 audio words, only the natural audio and the speech coding techniques were the standadization objects But in the MPEG-4 audio standadization, not only the natural audio and the speech coding, but also the structured audio and the synthetic speech techniques are inclued, The purpose of this expansion can be summarized as the preparation for the versatile high-quality multimedia services supposed emerge in the 21st century.

• Proceedings of the Korea Multimedia Society Conference
• /
• 2003.05b
• /
• pp.342-345
• /
• 2003

XMT (Extensible MPEG-4 Textual Format)는 텍스트 형식의 MPEG-4 씬 디스크립션으로 방송용 오디오/비디오 편집 및 이동 단말기 사용자 중심의 미디어 컨텐츠 개발에 활용될 수 있다. 본 논문에서는 다양한 재생 환경에서 컨텐츠의 상호 교환을 지원하는 XMT 저작도구를 개발하고 XMT의 2가지 파일 포맷인 XMT-A와 XMT-$\Omega$를 생성한다. 생성된 파일 포맷 중 XMT-$\Omega$를 이용하여 다양한 객체(비디오, 오디오, 이미지, 텍스트, 기하객체 등)의 시간공적인 특성들을 SMIL 파일로 변환하는 기법에 대해 제시하고 다양한 환경에서 멀티미디어의 상호교환성을 제공한다.

• Journal of KIISE:Software and Applications
• /
• v.27 no.8
• /
• pp.864-876
• /
• 2000

This paper proposes a new scene boundary detection scheme for the MPEG System stream using MPEG Audio information and proves its usefulness by extensive experiments. A scene boundary has a characteristic that the audio as well as video information are changed rapidly. This paper first classifies this scene boundary into three cases ; Radical, Gradual, Micro Changes, with respect to the audio changes. The Radical change has a large-scale changing of decibel value and pitch value at a scene boundary, the Gradual change shows the long-time transition of decibel and pitch values from max to min or vice versa, and the Micro change displays a some change of pitch or frequency distribution without decibel changes. Upon this analysis, a new scene change detection algorithm detecting these three cases is proposed in which a progressive window with a time line is used to trace the changes in the audio information. Some experiments with various movies show that proposed algorithm could produce a high detection ratio for Radical change that is the most popular scene change in the movies, while producing a moderate detection ratio for Gradual and Micro changes. The proposed scene boundary detection scheme could be used to build a database for visual information like MPEG System stream.

• The Journal of the Korea Contents Association
• /
• v.2 no.3
• /
• pp.105-112
• /
• 2002

MPEG-4 is an international standard for interactive multimedia data that is used for next generation audio-visual service. It presents an two types of storage formal such as XMT (eXtensible MPEG-4 Textual fount) and MP4 file format D store the interactive multimedia contents. The XMT, a textual format, has advantage of readability and it can be used in many applications since designed based on the XML In this paper, we present the way how to author the MPEG-4 contents using XMT.

• Proceedings of the Korean Society of Broadcast Engineers Conference
• /
• 2003.11a
• /
• pp.261-264
• /
• 2003

기존치 임베디드 시스템 환경에서 대용량의 멀티미디어 컨텐츠를 검색, 전송 및 재생하는데는 제한된 리소스로 인해 한계전이 있었다. 압축률이 좋고, 전송 및 재생에 효과적인 MPEG-4 시스템의 표준을 따르며. 다양한 대화형 멀티미디어를 프리젠테이션 할 수 있는 기법이 요구된다. 본 논문은 임베디드 시스템에서 DM과 연동하여 비디오/오디오의 재생 제어를 효율적으로 하고, 모듈을 동적으로 로드/언로드하여 저용량의 메모리를 사용하는 MPEG-4 미디어 프리젠테이션 기법을 제안한다.

• Proceedings of the Korea Multimedia Society Conference
• /
• 2004.05a
• /
• pp.334-337
• /
• 2004

컨텐츠를 저작하기 위하여 멀티미디어 요소로 사용되는 그래픽, 이미지, 오디오, 비디오 등의 여러 요소의 상호작용적인 관계를 저작할 수 있는 MPEG-4에 관하여 많은 연구가 이루어지고 있다. 이러한 연구의 결과는 저작과 재생뿐만 아니라 서비스, 유통 등에 대해 전반적으로 다루어진다. 개인용 컴퓨터의 사용과 더불어 휴대폰, PDA와 같은 무선 인터넷의 사용 빈도가 현저하게 증가하고 있으며, 모바일 환경에 MPEG-4 적용을 시도하는 것은 큰 의의를 가진다. 본 논문에서는 PC 환경에서 개발된 멀티미디어 컨텐츠 저작도구를 바탕으로 PDA 환경에 적합한 멀티미디어 컨텐츠 저작 방법을 제시하고 제안한 방법을 적용한 저작도구를 제시한다.