• The Transactions of the Korean Institute of Electrical Engineers P
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• v.52 no.2
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• pp.85-90
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• 2003

This paper has presented the efficient implementation of MPEG-4 simple profile video decoder, which is used as video compression standard in mobile video communication. We have used the ARM9 processor in implementing this MPEG-4 simple profile, which requires much processing power and low power implementation. At first we implemented with C-language under the PC environment with ADS(ARM Developer Suite) environment, and then we have tried to reduce a clock cycle for a power consumption optimization through conversion an assembly language for C-code partly. We have verified the processor is operated at 22.47MHz operation after optimization, but 148MHz before optimization.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.33 no.3C
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• pp.240-246
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• 2008

An MPEG-2/4 AAC decoder on 16-bit fixed-point processor is presented in this paper. To meet audio quality criteria, despite small word length, special design methods for 16-bit foxed-point AAC decoder were devised. This paper presents particular algorithms for 16-bit AAC decoding. We have implemented an efficient AAC decoder using the proposed algorithms. Audio contents can be replayed in the decoder without quality degradation.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.25 no.6B
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• pp.1060-1067
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• 2000

MPEG-4 visual coding is an object-based system. The current video coding standards, H.261, MPEG-1, and MPEG-2 encode frame by frame. On the other hand, MPEG-4 separately encodes several objects, such as video objects and audio objects, in the same frame. Each transmitted object is decoded and composed in one frame. Shape coding is a process of coding visual objects in a frame. In this paper we present conformance test method for MPEG-4 shape decoders. This paper reviews the basic shape decoding standard, and proposes conformance test methods for BAB type decoder, and CAE decoder for intra and inter VOPs. Our test generates all possible cases of shape motion vector difference and context.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.23 no.8
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• pp.2120-2130
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• 1998

This paper concerns a design of programmable MPEG decoder for video processing by object unit on network. The decoder can process video data effectively by a embedded controller with stack buffers for supporting OOP (Object-Oriented Programming). The controller offers extended instructions that process several data types including 32bit integer type. In addition to that, we have a vector processor, in this decoder that can execute advanced compensation and prediction by half pixel and SA(Shape Adaptive)-IDCT of MPEG-4. Absolutors and halfers in the vector processor make this architecture extensive to a encoder. We verified the decoder with $0.6\mu\textrm{m}$ 5-Volt CMOS COMPASS library.

• Proceedings of the IEEK Conference
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• 2006.06a
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• pp.355-356
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• 2006

MPEG-4 ER-BSAC decoder employes a full search method for maximum significance search and arithmetic decoding position search in spectral data decoding procedure. Then the search procedure have the most complexity. This paper proposes the new search method, the maximum significance tree structure, for the optimized implementation of BSAC decoder.

• IEIE Transactions on Smart Processing and Computing
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• v.3 no.5
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• pp.251-258
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• 2014

This paper proposes an efficient token flow design methodology for a decoder in the MPEG Reconfigurable Media Coding (RMC) framework. The MPEG RMC framework facilitates a decoder to be configured with a set of modules called functional units (FUs) that are connected by tokens. Such a modular design philosophy of the MPEG RMC framework enables the reusability and reconfigurability of FUs. One drawback of the MPEG RMC framework is that the decoder performance can be affected by increasing the token transmissions between FUs. The proposed method improves the design of the FU network in the RMC framework toward real-time decoder implementation. In the proposed method, the merging of FU, the separation of token flow, and the merging of token transactions are applied to minimize the token traffic between FUs. The experimental results of the MPEG-4 SP decoder show that the proposed method reduces the total decoding time by up to 77 percent compared to the design of the RMC simulation model.

• Proceedings of the Korean Information Science Society Conference
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• 2000.10b
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• pp.260-262
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• 2000

MPEG-4에서는 다양한 객체를 취급하기 위하여 시스템 부분(Part1)이 차지하는 비중이 MPEG-1이나 MPEG-2에서 보다 훨씬 높아졌다. 이러한 MPEG-4의 시스템 부분을 구현한 참조 모델을 IM1이라고 한다. IM1에는 다양한 오디오/비디오(A/V) 객체를 수용하기 위하여 디코더 프레임워크를 마련하고, 어떤 A/V 객체든 이 프레임워크에 맞추어 디코더를 구현하면 IM1 프리젠터에서 플레이가 가능토록 하고 있다. 현재 IM1 버전 3.8에서는 H.263 비디오, G.723 오디오, JPEG 이미지, AAC 오디오를 지원하고 있다. 이 논문에서는 MPEG-4 비디오 디코더를 IM1 디코더 프레임워크를 맞추어 설계, 수정한 내용을 기술하였다.

• Journal of Broadcast Engineering
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• v.13 no.4
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• pp.452-462
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• 2008

In this paper, we address issues associated with the real-time implementation of the MPEG-1/2 Layer-II (or MUSICAM) and MPEG-4 ER-BSAC decoders for Digital Multimedia Broadcasting (DMB) on TMS320C64x+ that is a fixed-point DSP processor with a clock speed of 330 MHz. To achieve the real-time requirement, they should be optimized in different steps as follows. First of all, a C-code level optimization is performed by sharing the memory, adjusting data types, and unrolling loops. Next, an algorithm level optimization is carried out such as the reconfiguration of bitstream reading, the modification of synthesis filtering, and the rearrangement of the window coefficients for synthesis filtering. In addition, the C-code of a synthesis filtering module of the MPEG-1/2 Layer-II decoder is rewritten by using the linear assembly programming technique. This is because the synthesis filtering module requires the most processing time among all processing modules of the decoder. In order to show how the real-time implementation works, we obtain the percentage of the processing time for decoding and calculate a RMS value between the decoded audio signals by the reference MPEG decoder and its DSP version implemented in this paper. As a result, it is shown that the percentages of the processing time for the MPEG-1/2 Layer-II and MPEG-4 ER-BSAC decoders occupy less than 3% and 11% of the DSP clock cycles, respectively, and the RMS values of the MPEG-1/2 Layer-II and MPEG-4 ER-BSAC decoders implemented in this paper all satisfy the criterion of -77.01 dB which is defined by the MPEG standards.

• Journal of the Korean Institute of Intelligent Systems
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• v.17 no.4
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• pp.477-482
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• 2007

This paper presents an audio decoder architecture which can decode AC-3 and MPEG-2 audio bit-streams efficiently. MPEG-2 synthesis filtering is modified by the 32-point FFT to share the common data path with the AC-3's. A programmable Audio DSP core and a hardwired common synthesis tilter are incorporated for effective decoding of two different formats.

• Proceedings of the IEEK Conference
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• 2000.09a
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• pp.295-298
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• 2000

본 논문에서는 WPEG가 적합성 검사를 위해 표준안에 명시된 조건하에서 검사를 수행한다. MPEG-4 encoder의 각 부분을 제어함으로써 shape coding에 대한 test를 수행하고 또한 검사하려는 항목을 고려하여 부호화 변수를 조절하면서 여러 종류의 test비트열을 생성하여 비교함으로써 MPEG-4 decoder의 객체기반 형상 부호화에 대한 적합성 검사를 수행한다.