To address the requirement of piecewise stationarity within the analyzed signal segments, today’s state of the art audio codecs make use of two filter bank resolutions. Short temporal resolution sequences are used to adapt to transient like jump signals, long temporal resolutions are used to effectively code the more steady or slowly drifting waveforms. With increasing computational capacity a better adaptation of the filter bank to the signal becomes feasible. The paper presents an experimental MDCT based transform coder which is capable of switching between four filter bank resolutions. A distortion measure is deployed which is driven by a simple psychoacoustic model that incorporates masking effects both for stationary and transient signals. A rate-distortion control is proposed to partition the signal to optimally match the signal contour with the temporal resolutions of the filter bank. Performance results are presented and compared to the conventional two resolution approach. Proposals for further developments, like pre-segmentation are evaluated.
Authors:
Boehm, Johannes; Jax, Peter; Kordon, Sven
Affiliations:
THOMSON; THOMSON, Research & Innovation, Audio Processing Lab Hannover(See document for exact affiliation information.)
AES Convention:
120 (May 2006)
Paper Number:
6810
Publication Date:
May 1, 2006
Subject:
Low Bit-Rate Audio Coding
Click to purchase paper as a non-member or you can login as an AES member to see more options.
No AES members have commented on this paper yet.
To be notified of new comments on this paper you can subscribe to this RSS feed. Forum users should login to see additional options.
If you are not yet an AES member and have something important to say about this paper then we urge you to join the AES today and make your voice heard. You can join online today by clicking here.