Method and apparatus for encoding audio signal, and method and apparatus for decoding audio signal

A method of encoding an audio signal, the method comprising:

• dividing an input audio signal into a plurality of audio bands;
• encoding audio data included in each of the audio bands according to each of a parametric coding method and a time-frequency coding method;
• selecting smaller data for each of the audio bands from among the encoded audio data using the parametric coding method and the time-frequency coding method;
• and
• generating a bit stream including all of the encoded audio data selected for each of the audio bands;
• wherein the selecting comprises determining which of the parametric coding method and the time frequency coding method would provide smaller encoded data for an audio band;
• wherein if it is determined that the parametric coding method would provide smaller encoded data for the audio band, selecting the parametric coding method for the audio band;
• wherein if it is determined that the time frequency coding method would provide smaller encoded data for the audio band, selecting the time frequency coding method for the audio band.

An apparatus for encoding an audio signal, the apparatus comprising:

• a band divider which divides an input audio signal into a plurality of audio bands;
• a coding method selector which selects a coding method for each of the audio bands;
• an audio encoder which encodes audio data included in each of the audio bands according to the coding method selected for each of the bands;
• and
• a bit stream generator which generates a bit stream including all of the encoded audio data for each of the audio bands,
• wherein the coding method selector selects a coding method providing smaller encoded data from among a parametric coding method and a time-frequency coding method;
• wherein the selecting comprises determining which of the parametric coding method and the time frequency coding method would provide smaller encoded data for an audio band;
• wherein if it is determined that the parametric coding method would provide smaller encoded data for the audio band, selecting the parametric coding method for the audio band;
• wherein if it is determined that the time frequency coding method would provide smaller encoded data for the audio band, selecting the time frequency coding method for the audio band.

A method of decoding an audio signal, the method comprising:

• dividing an input bit stream into audio data encoded for a plurality of audio bands;
• extracting information on a coding method used by an encoding apparatus for encoding the audio data, for each of the audio bands;
• decoding the encoded audio data for each of the audio bands, according to the coding method based on the extracted information;
• and
• generating the audio signal by combining the decoded audio data for the respective audio bands,
• wherein the coding method is a coding method providing smaller encoded data that is selected from among a parametric coding method and a time-frequency coding method;
• wherein the selecting comprises determining which of the parametric coding method and the time frequency coding method would provide smaller encoded data for an audio band;
• wherein if it is determined that the parametric coding method would provide smaller encoded data for the audio band, selecting the parametric coding method for the audio band;
• wherein if it is determined that the time frequency coding method would provide smaller encoded data for the audio band, selecting the time frequency coding method for the audio band.

An apparatus for decoding an audio signal, the apparatus comprising:

• a bit stream divider which divides an input bit stream into audio data encoded for a plurality of audio bands;
• a coding method extractor which extracts information on a coding method used by an encoding apparatus for encoding the audio data, for each of the audio bands;
• an audio decoder which decodes the encoded audio data for each of the audio bands, according to the coding method based on the extracted information;
• and
• an audio signal generator which generates the audio signal by combining the decoded audio data for each of the respective audio bands,
• wherein the coding method is a coding method providing smaller encoded data that is selected from a parametric coding method and a time-frequency coding method;
• wherein the selecting comprises determining which of the parametric coding method and the time frequency coding method would provide smaller encoded data for an audio band;
• wherein if it is determined that the parametric coding method would provide smaller encoded data for the audio band, selecting the parametric coding method for the audio band;
• wherein if it is determined that the time frequency coding method would provide smaller encoded data for the audio band, selecting the time frequency coding method for the audio band.

A non-transitory computer readable recording medium having recorded thereon a computer program for executing an audio signal encoding method, the audio signal encoding method comprising:

• dividing an input audio signal into a plurality of audio bands;
• selecting a coding method for each of the audio bands;
• encoding audio data included in each of the audio bands according to the coding method selected for each of the bands;
• and
• generating a bit stream including all the encoded audio data in each audio band,
• wherein the selecting the coding method comprises selecting a coding method providing smaller encoded data from among a parametric coding method and a time-frequency coding method;
• wherein the selecting comprises determining which of the parametric coding method and the time frequency coding method would provide smaller encoded data for an audio band;
• wherein if it is determined that the parametric coding method would provide smaller encoded data for the audio band, selecting the parametric coding method for the audio band;
• wherein if it is determined that the time frequency coding method would provide smaller encoded data for the audio band, selecting the time frequency coding method for the audio band.

A non-transitory computer readable recording medium having recorded thereon a computer program for executing an audio signal encoding method, the audio signal encoding method comprising:

• dividing an input audio signal into a plurality of audio bands;
• encoding audio data included in each of the audio bands by applying each of a parametric coding method and a time-frequency coding method respectively;
• selecting smaller data from among the encoded audio data using each of two different coding methods for each of the audio bands;
• and
• generating a bit stream including all of the encoded audio data selected for each of the audio bands;
• wherein the selecting comprises determining which of the parametric coding method and the time frequency coding method would provide smaller encoded data for an audio band;
• wherein if it is determined that the parametric coding method would provide smaller encoded data for the audio band, selecting the parametric coding method for the audio band;
• wherein if it is determined that the time frequency coding method would provide smaller encoded data for the audio band, selecting the time frequency coding method for the audio band.

A non-transitory computer readable recording medium having recorded thereon a computer program for executing an audio signal decoding method, the audio signal decoding method comprising:

• dividing an input bit stream into audio data encoded for a plurality of audio bands;
• extracting information on a coding method used by an encoding apparatus for encoding the audio data, for each of the audio bands;
• decoding the encoded audio data for each of the audio bands, according to the coding method based on the extracted information;
• and
• generating the audio signal by combining the decoded audio data for the respective audio bands,
• wherein the coding method is a coding method providing smaller encoded data that is selected from among a parametric coding method and a time-frequency coding method;
• wherein the selecting comprises determining which of the parametric coding method and the time frequency coding method would provide smaller encoded data for an audio band;
• wherein if it is determined that the parametric coding method would provide smaller encoded data for the audio band, selecting the parametric coding method for the audio band;
• wherein if it is determined that the time frequency coding method would provide smaller encoded data for the audio band, selecting the time frequency coding method for the audio band.