Journal of the Institute of Electronics and Information Engineers (전자공학회논문지)

The Institute of Electronics and Information Engineers (대한전자공학회)
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Improved Phase Synthesis for Parametric Stereo Audio Coding

파라메트릭 스테레오 오디오 부호화를 위한 향상된 위상 합성 기법

  • Hyun, Dong-Il (School of Electrical and Electronic Engineering, Yonsei University) ;
  • Park, Young-Cheol (Computer and Telecommunications Engineering Division, Yonsei University) ;
  • Youn, Dae Hee (School of Electrical and Electronic Engineering, Yonsei University)
  • 현동일 (연세대학교 전기전자공학과) ;
  • 박영철 (연세대학교 컴퓨터정보통신공학부) ;
  • 윤대희 (연세대학교 전기전자공학과)
  • Received : 2013.09.29
  • Accepted : 2013.12.02
  • Published : 2013.12.25
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Abstract

Parametric stereo(PS) audio coding is a specific version of spatial audio coding. In this paper, the problem due to the conventional synthesis of phase differences. In the conventional upmix matrix, phase differences are synthesized not only on downmix signal but also ambient signal, which violates the assumption that the ambient signals are anti-phased. Deterioration due to the phase synthesis is analyzed, especially, for low interchannel correlation. To solve this problem, new upmix matrix is proposed, which synthesizes phase differences only on downmix signal. The performance of the proposed upmix matrix is verified by the subjective listening tests.

파라메트릭 스테레오 오디오 부호화는 공간 오디오 기법 중 스테레오에 특화된 부호화 기법이다. 본 논문에서는 기존의 파라메트릭 스테레오 기법에서 채널간 위상차 합성시 발생하는 문제점을 분석하였다. 기존의 업믹스 행렬에서는 채널간 위상차를 다운믹스 신호뿐만 아니라 잔향신호에도 합성하고 이로 인하여 반위상 관계를 위반한다. 채널간 상관도가 낮을 때, 잔향 성분에 대한 채널간 위상차 합성으로 인하여 발생하는 음질열화를 분석하였다. 이러한 문제점들을 해결하기 위하여 신호 모델을 만족할 수 있도록 주요 성분에만 채널간 위상차를 합성하는 업믹스 행렬을 제안하였다. 주관적 음질 평가를 통하여 제안된 업믹스 행렬의 성능을 검증하였다.

Keywords

References

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