Backward-compatible integration of harmonic transposer for high frequency reconstruction of audio signals

Abstract

A method for decoding an encoded audio bitstream is disclosed. The method includes receiving the encoded audio bitstream and decoding the audio data to generate a decoded low band audio signal. The method further includes extracting high frequency reconstruction metadata and filtering the decoded low band audio signal with an analysis filter bank to generate a filtered low band audio signal. The method also includes extracting a flag indicating whether either spectral translation or harmonic transposition is to be performed on the audio data and regenerating a high band portion of the audio signal using the filtered low band audio signal and the high frequency reconstruction metadata in accordance with the flag.