Method and apparatus for reversibly encoding the original signal using a lossy encoded data stream and lossless extension data stream

摘要

The invention is related to lossless encoding of a source signal (S PCM ), using a lossy encoded data stream and a lossless extension data stream which together form a lossless encoded data stream (S ENC ) for said source signal, whereby lossless audio compression means audio coding with bit-exact reproduction of the original PCM samples at decoder output. The lossy encoding/decoding may be an mp3 coding/decoding. The invention uses an integer MDCT and frequency domain decorre-lation (16) and time domain de-correlation (16) for the residual signal of the base-layer lossy audio codec. The exploitation of side information from the lossy base-layer codec allows for reduction of redundancies in the gross bit stream, thus improving the coding efficiency of the lossy based lossless codec.