METHOD AND APPARATUS FOR LOSSLESS ENCODING OF A SOURCE SIGNAL USING A LOSSY ENCODED DATA STREAM AND A LOSSLESS EXTENSION DATA STREAM

摘要

In lossy based lossless coding a PCM audio signal passes through a lossy encoder (41) to a lossy decoder (42). The lossy encoder provides a lossy bit stream. The difference signal (SDiff) between the PCM signal and the lossy decoder output is lossless encoded (52), providing an extension bit stream. The invention facilitates enhancing a lossy percep tual audio encoding/decoding by an extension that enables mathematically exact reproduction of the original waveform using enhanced de-correlation, and provides additional data for reconstructing at decoder site an intermediate-quality audio signal. The lossless extension can be used to extend the widely used mp3 encoding/decoding to lossless encoding/decoding and superior quality mp3 encoding/de-coding.