Method of and apparatus for converting an audio signal between data compression formats

摘要

Useful subband information which is present in a first audio signal (for example, MPEG 1 Layer II) is discarded in the conventional approach of format conversion, only to be regenerated when encoding to the target format (for example, MPEG 1 Layer III). Instead, in the present invention, this useful subband information is re-used directly or indirectly in order to eliminate the conventional requirement to fully decode to PCM and then encode again.