Audio decoder core MPEG-1/MPEG-2/AC-3 functional algorithm partitioning and implementation

摘要

A digital audio decoder is described. The digital audio decoder includes: (i) an audio core which defines a hardware for sub-band synthesis and windowing during decoding of MPEG and AC-3 digital audio signals; (ii) an input RAM coupled to the audio core and configured to store discrete samples in preparation for the sub-band synthesis and the windowing and configured to store intermediate values that are calculated by the audio core during the sub-band synthesis and written back to the input RAM.;A process of decoding MPEG and AC-3 digital audio signals is also described. The process includes: (i) providing a digital audio decoder including firmware and hardware that are configured to decode MPEG or AC-3 digital audio signals; (ii) receiving MPEG or AC-3 encoded digital audio signals; (iii) decoding at least partially the digital audio signals by the firmware using MPEG or AC-3 audio algorithms that precede sub-band synthesis and windowing; and (iv) performing the sub-band synthesis and the windowing on MPEG or AC-3 digital audio signals by the hardware, wherein for a period of time the decoding of the digital audio signals by the firmware and performing the sub-band synthesis and the windowing by the hardware are carried out simultaneously.