A spectrum coding method includes quantizing spectral data of a current band based on a first quantization scheme, generating a lower bit of the current band using the spectral data and the quantized spectral data, quantizing a sequence of lower bits including the lower bit of the current band based on a second quantization scheme, and generating a bitstream based on a upper bit excluding N bits, where N is 1 or greater, from the quantized spectral data and the quantized sequence of lower bits.

Disclosed are a method for coding a residual signal of LPC coefficients based on collaborative quantization and a computing device for performing the method. The residual signal coding method includes: generating encoded LPC coefficients and LPC residual signals by performing LPC analysis and quantization on an input speech; Determining a predicted LPC residual signal by applying the LPC residual signal to cross module residual learning; Performing LPC synthesis using the coded LPC coefficients and the predicted LPC residual signal; It may include the step of determining an output speech that is a synthesized output according to a result of performing the LPC synthesis.

Disclosed are a method for coding a residual signal of LPC coefficients based on collaborative quantization and a computing device for performing the method. The residual signal coding method includes: generating encoded LPC coefficients and LPC residual signals by performing LPC analysis and quantization on an input speech; Determining a predicted LPC residual signal by applying the LPC residual signal to cross module residual learning; Performing LPC synthesis using the coded LPC coefficients and the predicted LPC residual signal; It may include the step of determining an output speech that is a synthesized output according to a result of performing the LPC synthesis.

This application provides example psychoacoustics-based audio encoding methods and apparatuses. One example method includes receiving audio data. The audio data can be decoded. Auditory feature information of a user can be obtained, where the auditory feature information includes at least one of the following: personal information, listening test result information, or frequency response curve information. A psychoacoustics model parameter of the user can be calculated based on the auditory feature information of the user, where the psychoacoustics model parameter includes at least one of the following: an intra-band masking parameter, a slope of a low-frequency inter-band masking line, a slope of a high-frequency inter-band masking line, or a human ear quiet threshold curve. The decoded audio data can be encoded based on the psychoacoustics model parameter of the user.

An apparatus comprising means configured to: generate spatial audio signal directional metadata parameters for a block of time-frequencies; generate encoded spatial audio signal directional metadata parameters (108) for a block of time-frequencies based on a first quantization resolution (203); compare a number of bits used for the encoded spatial audio signal directional parameters (108) for the block of time-frequencies based on the first quantization resolution against a determined number of bits; output or store the encoded spatial audio signal directional metadata parameters for a block of time-frequencies (108) based on a first quantization resolution when the number of bits used for the encoded spatial audio signal directional parameters for the block of time-frequencies (108) based on the first quantization resolution is less than a determined number of bits (217); generate encoded spatial audio signal directional metadata parameters (108) for the block of time-frequencies based on a second quantization resolution when the number of bits used for the encoded spatial audio signal directional parameters for the block of time-frequencies (108) based on the first quantization resolution is more than the determined number of bits and a difference between the determined number of bits and the number of bits used for the encoded spatial audio signal directional parameters (108) for the block of time-frequencies based on the first quantization resolution is less than a determined number of bits is within a determined threshold (217); generate encoded spatial audio signal directional metadata parameters (108) for the block of time-frequencies based on a third quantization resolution when the number of bits used for the encoded spatial audio signal directional parameters (108) for the block of time-frequencies based on the first quantization resolution is more than the determined number of bits and the difference between the determined number of bits and the number of bits used for the encoded spatial audio signal directional parameters (108) for the block of time-frequencies based on the first quantization resolution is greater than the determined threshold, wherein the third quantization resolution is determined such that a number of bits used for the encoded spatial audio signal directional parameters for the block of time-frequencies based on the third quantization resolution is always equal to or less than the determined number of bits (217).

An apparatus comprising means configured to: generate spatial audio signal directional metadata parameters for a block of time-frequencies; generate encoded spatial audio signal directional metadata parameters (108) for a block of time-frequencies based on a first quantization resolution (203); compare a number of bits used for the encoded spatial audio signal directional parameters (108) for the block of time-frequencies based on the first quantization resolution against a determined number of bits; output or store the encoded spatial audio signal directional metadata parameters for a block of time-frequencies (108) based on a first quantization resolution when the number of bits used for the encoded spatial audio signal directional parameters for the block of time-frequencies (108) based on the first quantization resolution is less than a determined number of bits (217); generate encoded spatial audio signal directional metadata parameters (108) for the block of time-frequencies based on a second quantization resolution when the number of bits used for the encoded spatial audio signal directional parameters for the block of time-frequencies (108) based on the first quantization resolution is more than the determined number of bits and a difference between the determined number of bits and the number of bits used for the encoded spatial audio signal directional parameters (108) for the block of time-frequencies based on the first quantization resolution is less than a determined number of bits is within a determined threshold (217); generate encoded spatial audio signal directional metadata parameters (108) for the block of time-frequencies based on a third quantization resolution when the number of bits used for the encoded spatial audio signal directional parameters (108) for the block of time-frequencies based on the first quantization resolution is more than the determined number of bits and the difference between the determined number of bits and the number of bits used for the encoded spatial audio signal directional parameters (108) for the block of time-frequencies based on the first quantization resolution is greater than the determined threshold, wherein the third quantization resolution is determined such that a number of bits used for the encoded spatial audio signal directional parameters for the block of time-frequencies based on the third quantization resolution is always equal to or less than the determined number of bits (217).

In some embodiments, a pitch filter for filtering a preliminary audio signal generated from an audio bitstream is disclosed. The pitch filter has an operating mode selected from one of either: (i) an active mode where the preliminary audio signal is filtered using filtering information to obtain a filtered audio signal, and (ii) an inactive mode where the pitch filter is disabled. The preliminary audio signal is generated in an audio encoder or audio decoder having a coding mode selected from at least two distinct coding modes, and the pitch filter is capable of being selectively operated in either the active mode or the inactive mode while operating in the coding mode based on control information.

In some embodiments, a pitch filter for filtering a preliminary audio signal generated from an audio bitstream is disclosed. The pitch filter has an operating mode selected from one of either: (i) an active mode where the preliminary audio signal is filtered using filtering information to obtain a filtered audio signal, and (ii) an inactive mode where the pitch filter is disabled. The preliminary audio signal is generated in an audio encoder or audio decoder having a coding mode selected from at least two distinct coding modes, and the pitch filter is capable of being selectively operated in either the active mode or the inactive mode while operating in the coding mode based on control information.

In a stereo encoding method, a channel combination encoding solution of a current frame is first obtained, and then a quantized channel combination ratio factor of the current frame and an encoding index of the quantized channel combination ratio factor are obtained based on the obtained channel combination encoding solution, so that an obtained primary channel signal and secondary channel signal of the current frame meet a characteristic of the current frame.

In a stereo encoding method, a channel combination encoding solution of a current frame is first obtained, and then a quantized channel combination ratio factor of the current frame and an encoding index of the quantized channel combination ratio factor are obtained based on the obtained channel combination encoding solution, so that an obtained primary channel signal and secondary channel signal of the current frame meet a characteristic of the current frame.