A \u201cSTAC Codec\u201d provides audio transcoding and decoding by processing an encoded audio signal using a backward-adaptive run-length Golomb-Rice decoder to recover transform coefficients of the encoded audio signal. 0 through an Ethernet TCPIP medium. A check box is selected in order to set so that AV contents recorded as compression data of the MPEG 2 system on the HDD are copied onto the external recording medium after they are converted into compression data of the MPEG 1 system which has compatibility with a video CD.