Decoding device

A decoding device for decoding a first bit stream defined by MPEG1 and a second bit stream defined by MPEG2 Audio Multichannel (MC),

• the first bit stream including an MPEG1 compatible area,
• the second bit stream including the MPEG1 compatible area and an MPEG2 multichannel extended area,
• the MPEG1 compatible area including MPEG1 side information,
• the decoding device comprising:
• MPEG1 decoding means for decoding the MPEG1 compatible area;
• MC decoding means for decoding the MPEG2 multichannel extended area;
• and
• MC header detection means for executing a first processing including locating a position of a header of the MPEG2 multichannel extended area based on the MPEG1 side information and shifting a read position of the bit stream to the position of the header,
• wherein the MC header detection means executes the first processing on the way to a processing of the MPEG1 decoding means,
• the MC decoding means reads information from the position after the MC header detection means executes the first processing, and executes the error check (CRC) for the information,
• when results of the CRC are normal, the decoding device alternately executes the decoding of the MPEG1 compatible area by the MPEG1 decoding means and the decoding of the MPEG2 multichannel extended area by the MC decoding means, and
• when the results of the CRC are abnormal, the decoding device executes only the decoding of the MPEG1 compatible area by the MPEG1 decoding means.

A decoding device for decoding a first bit stream defined by MPEG1 and a second bit stream defined by MPEG2 Audio Multichannel (MC),

• the first bit stream including an MPEG1 compatible area,
• the second bit stream including the MPEG1 compatible area and an MPEG2 multichannel extended area,
• the MPEG1 compatible area including MPEG1 side information,
• the decoding device comprising:
• MPEG1 decoding means for decoding the MPEG1 compatible area;
• MC decoding means for decoding the MPEG2 multichannel extended area;
• and
• MC header detection means for executing a first processing including locating a position of a header of the MPEG2 multichannel extended area based on the MPEG1 side information and shifting a read position of the bit stream to the position of the header,
• wherein the MC header detection means executes the first processing on the way to a processing of the MPEG1 decoding means,
• the MC decoding means determines whether or not the number of channels in the MPEG2 multichannel extended area is zero based on information read from a position where MC side information for the MPEG2 multichannel extended area is stored, and
• if the number of channels in the MPEG2 multichannel extended area is zero, the decoding of the MPEG2 multichannel extended area is not performed, but only the MPEG1 compatible area is decoded.

A decoding device for decoding a first bit stream defined by MPEG1 and a second bit stream defined by MPEG2 Audio Multichannel (MC),

• the first bit stream including an MPEG1 compatible area,
• the second bit stream including the MPEG1 compatible area and an MPEG2 multichannel extended area,
• the MPEG1 compatible area including MPEG1 side information,
• the decoding device comprising:
• MPEG1 decoding means for decoding the MPEG1 compatible area;
• and
• MC decoding means for decoding the MPEG2 multichannel extended area,
• wherein the decoding device terminates the decoding if a length of the bit stream consumed in the decoding of the MPEG2 multichannel extended area by the MC decoding means exceeds a stream length of one frame, and decodes only the MPEG1 compatible area.