Patent ID: 7555434
Filing Date: 2009-06-30
Classification: G10L

Abstract:
1. An audio decoding apparatus comprising: a bit stream separator for separating a bit stream into a low-frequency bit stream and a high-frequency bit stream; a low-frequency decoder for decoding said low-frequency bit stream to generate a low-frequency audio signal; a subband divider for dividing said low-frequency audio signal into a plurality of real-valued signals in respective frequency bands to generate low-frequency subband signals; an energy corrector for outputting an energy corrective coefficient for a signal which is generated by copying and processing said low-frequency subband signals; a band expander for generating a high-frequency subband signal by correcting, in amplitude, the signal energy of the signal which is generated by copying and processing said low-frequency subband signals as instructed by said high-frequency bit stream, using said energy corrective coefficient; and a subband combiner for combining said low-frequency subband signals and said high-frequency subband signals to produce a decoded audio signal, wherein said energy corrector calculates the signal phase of said low-frequency subband signals and calculates the energy corrective coefficient based on said signal phase.