Method and apparatus for encoding/decoding multi-channel audio signal by using semantic information

A multi-channel audio signal decoding method, the method comprising:

• determining information about similar channels from an audio bitstream;
• extracting audio signals of the similar channels from the audio bitstream based on the determined information;
• and
• decoding spatial parameters between the similar channels and up-mixing the extracted audio signals of the similar channels using similar channels so as to enhance a channel separation,
• wherein the determining comprises comparing a degree of similarity between the channels with a predetermined threshold.

A multi-channel audio signal decoding method, the method comprising:

• determining semantic information from an audio bitstream;
• determining a degree of similarity between channels based on the determined semantic information using similar channels so as to enhance a channel separation;
• extracting audio signals of the similar channels from the audio bitstream based on the determined degree of similarity between the channels;
• decoding spatial parameters between similar channels and up-mixing the extracted audio signals of the similar channels,
• wherein the determining the degree of similarity between the channels comprises comparing the degree of similarity between multi-channels with a predetermined threshold.

A multi-channel audio signal encoding apparatus, the apparatus comprising:

• a channel similarity determining unit which determines a degree of similarity between multi-channels based on semantic information for each channel;
• a channel signal processing unit which generates spatial parameters between similar channels determined by the channel similarity determining unit, and down-mixes audio signals of the similar channels using the similar channels so as to enhance a channel separation on a decoder;
• a coding unit which encodes the down-mixed audio signals of the similar channels processed by the signal processing unit by using a predetermined codec;
• and
• a bitstream formatting unit which adds the semantic information for each channel or information about the similar channels to the audio signals encoded by the coding unit, and formats the audio signals as a bitstream,
• wherein the channel similarity determining unit compares the degree of similarity between multi-channels with a predetermined threshold.

A multi-channel audio signal decoding apparatus, the apparatus comprising:

• a channel similarity determining unit which determines a degree of similarity between a plurality of channels of the multi-channel audio signal from semantic information for each channel and extracts audio signals of similar channels based on the determined degree of similarity between the plurality of channels;
• an audio signal synthesis unit which decodes spatial parameters between the similar channels extracted by the channel similarity determining unit using the similar channels so as to enhance a channel separation, and synthesizes the extracted audio signals of each sub-band by using the spatial parameters;
• a decoding unit which decodes the audio signals synthesized by the audio signal synthesis unit by using a predetermined codec;
• and
• an up-mixing unit which up-mixes the audio signals of the similar channels decoded by the decoding unit,
• wherein the channel similarity determining unit compares the degree of similarity between the plurality of channels with a predetermined threshold.

A non-transitory computer readable recording medium storing instruction for encoding a multi-channel audio signal, the instructions comprising:

• determining semantic information for at least two channels of the multi-channel audio
• signal;
• determining degree of similarity between the at least two channels based on the determined semantic information using similar channels so as to enhance a channel separation on a decoder;
• and
• if the degree of similarity exceed a predetermined threshold, extract spatial parameters between the at least two channels and down-mix audio signals of the at least two channels:
• wherein the determining the degree of similarity comprises comparing a degree of similarity between the at least two channels with a predetermined threshold.