System, method and computer readable medium of efficiently decod

Details System, method and computer readable medium of efficiently decod System, method and computer readable medium of efficiently decod

1996-12-23

1999-10-19

Hudspeth, David R.

Data processing: speech signal processing, linguistics, language

Audio signal bandwidth compression or expansion

704204, G06K 936

Patent

active

059704616

ABSTRACT:
A method and system for providing an inverse transform for an audio compression decoding algorithm in software precalculates a plurality of identified values; each of which is computationally intensive. The method and system then performs a pre-inverse transform complex multiply utilizing a first portion of the identified values and an array of input coefficients to provide a plurality of intermediate values. Thereafter, an inverse transform complex multiply and a post inverse transform multiply are combined to provide a combined complex multiply operation. The combined complex multiply operation uses a second portion of the identified values and the intermediate values provides the inverse transform. Accordingly, through the use of the present invention, the number of instructions for implementing the inverse transform can be substantially minimized. In the prior art, the method for performing the inverse discrete cosine transform (IDCT) in the AC-3 algorithm is extremely inefficient for software decoder implementations. Through the use of the present invention, the algorithm performance on a superscalar processor as measured by issued instructions is improved by a factor on the order of 43.

REFERENCES:
patent: 4829573 (1989-05-01), Gagnon et al.
patent: 5007101 (1991-04-01), Iwahashi et al.
patent: 5815206 (1998-09-01), Malladi et al.
Srinivasan et al. VLSI Design of High Speed Time Recursive 2-D DCT/IDCT Process, IEEE Transactions on Circuits and System for Video Technology, vol. 6, Issue 1, Feb. 1996.
Madisetti et al. DCT/IDCT processor design for HDTV applications. Signals, Systems and Electronics, 1995 International Symposium, 1995.
Li, Weiping. A new algorithm to compute the DCT and its invers. IEEE Transactions on Signal Processing, Jun. 1991.
Zhou, Minli. Vector-radix IDCT implementation for MPEG decoding. ASIC Conference and Exhibit, 1995.
Wang, Zhongde. Recursive Algorithms for the forward and inverse discrete cosine transform. IEEEE Signal Processing Letters, Jul. 1994.
"Design and Implementation of AC-3 Coders," Steve Vernon, IEEE Transactions on Consumer Electronics, vol. 41, No. 3, Aug. 3, 1995.
Digital Audio Compression Statndard (AC-3) pp. 87-93, Dec. 1995.
Beyer, William. CRC Standard Mathematical Tables. CRC Press, Inc. Florida, 1981.

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