Method, medium, and apparatus encoding and/or decoding multichannel audio signals

A non-transitory computer readable recording medium having embodied thereon a computer program for executing a method of decoding spatial extension data, wherein the method comprises:

• determining a type of spatial extension data included in a bitstream;
• if the type of the spatial extension data is determined to be residual coding data, decoding residual coding data based on a first decoding scheme;
• and
• if the type of the spatial extension data is determined to be arbitrary down-mixed residual coding data, decoding arbitrary down-mixed residual coding data based on a second decoding scheme.

An apparatus, including at least one processing device, for decoding spatial extension data, the apparatus comprising:

• a spatial extension data type detecting unit determining, using the at least one processing device, a type of spatial extension data included in a bitstream;
• a residual coding data decoding unit, if the type of the spatial extension data is determined to be residual coding data, decoding residual coding data based on a first decoding scheme;
• and
• an arbitrary down-mix residual coding data decoding unit, if the type of the spatial extension data is determined to be arbitrary down-mixed residual coding data, decoding arbitrary down-mixed residual coding data based on a second decoding scheme.

A method of encoding spatial extension data, the method comprising:

• generating at least one of residual data and arbitrary down-mix residual data by down-mixing an input audio signal;
• if the residual data is generated,
• encoding the residual data by using a first encoding scheme;
• if the arbitrary down-mix residual data is generated, encoding the arbitrary down-mix residual data by using a second encoding scheme;
• and
• outputting at least one of the encoded residual data and the encoded arbitrary down-mix residual data.

An apparatus, including at least one processing device, for encoding spatial extension data, the apparatus comprising:

• a down-mixing unit generating, using the at least one processing device, at least one of residual data and arbitrary down-mix residual data by down-mixing an input audio signal;
• a residual data encoding unit encoding, if the residual data is generated, the residual data by using a first encoding scheme;
• an arbitrary down-mix residual data encoding unit encoding, if the arbitrary down-mix residual data is generated, the arbitrary down-mix residual data by using a second encoding scheme;
• and
• a multiplexing unit outputting at least one of the encoded residual data and the encoded arbitrary down-mix residual data.

A multi-channel decoding method comprising:

• decoding a mono down-mixed signal included in a bitstream;
• decoding side information for generating a plurality of channel signals from the decoded mono down-mixed signal, included in the bitstream, in consideration with information indicating whether a residual coding has been applied;
• decoding a residual signal included in the bitstream, based on the information indicating whether the residual coding has been applied;
• and
• reconstructing the plurality of channel signals by upmixing the mono down-mixed signal using the decoded side information and the decoded residual signal.