Optimized recursive subband synthesis windowing for implementing efficient MPEG audio decoders

Abstract

In this letter, we discuss a recursive optimization approach for the subband synthesis windowing component used in all three layers of the MPEG-1 and -2 audio decoding frameworks. We explain the design of the proposed algorithm and briefly discuss how it can be combined with other novel and existing optimization strategies. The impact of these optimizations on the number of multiplications and additions is shown, and the influence of the algorithm on the amount of memory required by the adapted decoder is also discussed. We show that the proposed algorithm offers very interesting possibilities for implementing efficient VLSI designs.Index Terms-Efficient decoder, MPEG audio, recursive windowing.

Suppression of delta-sigma DAC quantisation noise by bandwidth adaptation

“…The decoder was instrumented with the proposed method for obtaining spectral information, thus sensing spectral properties in real-time. Optimisations described in [13] and [14] were applied to the subband filtering component to verify that our approach is independent of optimisations applied to the decoder. A multistage polyphase lowpass FIR filter was implemented to apply eight times interpolation to the output of the MPEG decoder.…”

Do not zero-pute

“…As already indicated earlier, in real-life situations it can be inefficient to implement the matrixing procedure as formulated in all three equations given above; it is a well-known fact that Eq. (1) can be simplified based on the properties of the cosinefunction; see also [4], and [5].…”