Fast algorithms for computation of 5-point dct-II, dct-IV, and dst-IV, and architectures

Abstract

A more efficient encoder / decoder is provided in which an N-point MDCT transform is mapped into smaller sized N / 2-point DCT-IV, DST-IV and / or DCT-II transforms. The MDCT may be systematically decimated by factor of 2 by utilizing a uniformly scaled 5-point DCT-II core function as opposed to the DCT-IV or FFT cores used in many existing MDCT designs in audio codecs. Various transform factorizations of the 5-point transforms may be implemented to more efficiently implement a transform.

Description

[0001] Claim of priority under 35 U.S.C. §119 [0002] This patent application asserts that the title filed on December 13, 2007 is "A Fast Algorithm for Computing 5-point Discrete Cosine Transform-II, Discrete Cosine Transform-IV and Discrete Sine Transform-V, and for Designing Size N= 5*2 K Transformation architecture (Fast Algorithms for Computation of 5-Point DCT-II, DCT-IV, and DST-V, and Architecture for Design of Transforms of Size N=5*2 K )" and U.S. Provisional Application No. 61 / 039,194, filed March 25, 2008, entitled "G.EV-VBR MDCT Module (G.EV-VBR MDCTModule)" Priority of the said application is assigned to the present assignee and is hereby expressly incorporated herein by reference. technical field [0003] The following description relates generally to encoders and decoders, and in particular to efficient MDCT / IMDCT implementations for speech and audio codecs. Background technique [0004] One goal of audio coding is to compress an audio signal to the desi...

AI Technical Summary

Problems solved by technology

[0007] However, if future vocoders are to support block swapping functionality, support for decimated sizes (e.g., 160 points, 80 points, 40 points) may also be required

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