Patents Assigned to Formosoft International Inc.
  • Patent number: 6119080
    Abstract: A unified architecture for implementing the modified cosine transforms of various cosine modulated filter banks in audio compression standards comprises a permutation module and a transform computing module. A modified cosine transform is computed by a pre-permutation followed by a discrete cosine transform and an inverse modified cosine transform is computed by a discrete cosine transform followed by a post-permutation. The discrete cosine transform computed in the unified architecture is selected from the group of type-II, type-III and type-IV cosine transforms. The computation of an N point discrete cosine transform is decomposed into a permutation-add stage, a sub-transform stage for computing two N/2 point discrete cosine transforms selected from the same group, and a combination stage. The architecture results in good regularity and general applicability as well as reduces complexity.
    Type: Grant
    Filed: June 17, 1998
    Date of Patent: September 12, 2000
    Assignee: Formosoft International Inc.
    Inventors: Chi-Min Liu, Wen-Chieh Lee