Abstract: A stereo signal encoding method includes: obtaining a residual signal encoding parameter of a current frame of a stereo signal based on downmixed signal energy and residual signal energy of each of M sub-bands of the current frame, where the residual signal encoding parameter indicates whether to encode residual signals of the M sub-bands; determining whether to encode the residual signals based on the residual signal encoding parameter; and encoding the residual signals when it is determined that the residual signals need to be encoded.

Abstract: A signal processing method and device includes obtaining spectral coefficients of a current frame of an audio signal, in which N sub-bands of the current frame comprises at least one of the spectral coefficients. A total energy of M successive sub-bands of the N sub-bands, a total energy of K successive sub-bands of the N sub-bands, and an energy of a first sub-band are obtained to determine whether to modify original envelope values of the M sub-bands. When the original envelope values of the M sub-bands are modified, encoding bits are allocated to each of the N sub-bands according to the modified envelope values of the M sub-bands.

Abstract: An inter-channel phase difference (IPD) parameter extraction method includes obtaining a parameter for obtaining an information extraction manner for a current frame of a multi-channel signal; obtaining an IPD parameter extraction manner for the current frame based on the parameter for obtaining the information extraction manner, where the obtained IPD parameter extraction manner is one of at least two preset IPD parameter extraction manners; and obtaining an IPD parameter of the current frame based on the obtained IPD parameter extraction manner for the current frame.

Abstract: An encoding method includes dividing a to-be-encoded time-domain signal into a low band signal and a high band signal, performing encoding on the low band signal to obtain a low frequency encoding parameter, performing encoding on the high band signal to obtain a high frequency encoding parameter, obtaining a synthesized high band signal, performing short-time post-filtering processing on the synthesized high band signal to obtain a short-time filtering signal, and calculating a high frequency gain based on the high band signal and the short-time filtering signal.

Abstract: A multi-channel signal encoding method includes obtaining a multi-channel signal of a current frame; determining an initial multi-channel parameter of the current frame; determining a difference parameter based on the initial multi-channel parameter of the current frame and multi-channel parameters of previous K frames of the current frame, where the difference parameter represents a difference between the initial multi-channel parameter of the current frame and the multi-channel parameters of the previous K frames, and K is an integer greater than or equal to one; determining a multi-channel parameter of the current frame based on the difference parameter and a characteristic parameter of the current frame; and encoding the multi-channel signal based on the multi-channel parameter of the current frame.

Abstract: This application discloses a downmixed signal calculation method and apparatus. The method includes: when a current frame or a previous frame of the current frame of a stereo signal is not a switching frame and a residual signal in the current frame or the previous frame does not need to be encoded, obtaining a second downmixed signal in the current frame and a downmix compensation factor of the current frame, correcting the second downmixed signal in the current frame based on the downmix compensation factor of the current frame, to obtain the first downmixed signal in the current frame and determining the first downmixed signal in the current frame as a downmixed signal in the current frame in a preset frequency band.

Abstract: A method comprises adjusting, based on an adjustment factor, a quantized energy envelope of a subband of a frame of an audio signal to obtain an adjusted quantized energy envelope of the subband. Bit allocation for a plurality of subbands of the frame is performed based on the adjusted quantized energy envelope, wherein at least one subband in the plurality of subbands has at least one allocated bit. At least a part of spectral coefficients included in the at least one subband is quantized, based on the at least one allocated bit, to obtain quantized spectral coefficients. A bitstream is obtained that includes the quantized spectral coefficients.

Abstract: An automatic and rapid detection method of a gradation for an asphalt mixture and an automatic device are provided. The method includes: asphalt mixture introduction; asphalt mixture dehydration, including: heating the asphalt mixture and dehydrating to a target dehydration rate; asphalt combustion, including: burning the asphalt mixture by using a combustion method to form smoke to be removed, thereby obtaining aggregates, and obtaining an asphalt content; aggregate screening, including: grading through screening the aggregates according to different particle sizes by using a vibration screening device, and then weighing the aggregates, thereby obtaining weights of the aggregates; and obtaining the gradation, including: calculating the gradation for the asphalt mixture according to the weights of the aggregates with the different particle sizes and the asphalt content.

Abstract: A multi-channel signal encoding method includes determining a downmixed signal of a first channel signal and a second channel signal, determining an initial reverberation gain parameter of the first channel signal and the second channel signal, determining a target reverberation gain parameter of the first channel signal and the second channel signal based on a correlation between the first channel signal and the downmixed signal, a correlation between the second channel signal and the downmixed signal, and the initial reverberation gain parameter, quantizing the first channel signal and the second channel signal based on the downmixed signal and the target reverberation gain parameter, and writing a quantized first channel signal and a quantized second channel signal into a bitstream.

Abstract: In a method to decode signals, a computing device decodes spectral coefficients of a current frame are grouped into a plurality of sub-bands. The computing device classifies a sub-band as a bit allocation unsaturated sub-band based on an average quantity of allocated bits per spectral coefficient of a sub-band of the plurality of sub-bands and a threshold. The computing device obtains a noise filling gain based on an envelope of the sub-band, and obtains a reconstructed spectral coefficient of the sub-band by performing noise filling based on the noise filling gain. The computing device then obtains a frequency domain audio signal based on spectral coefficients in the sub-band obtained by decoding and the reconstructed spectral coefficient.

Abstract: A signal processing method and device includes obtaining spectral coefficients of a current frame of an audio signal, in which N sub-bands of the current frame comprises at least one of the spectral coefficients. A total energy of M successive sub-bands of the N sub-bands, a total energy of K successive sub-bands of the N sub-bands, and an energy of a first sub-band are obtained to determine whether to modify original envelope values of the M sub-bands. When the original envelope values of the M sub-bands are modified, encoding bits are allocated to each of the N sub-bands according to the modified envelope values of the M sub-bands.

Abstract: An encoding method includes dividing a to-be-encoded time-domain signal into a low band signal and a high band signal, performing encoding on the low band signal to obtain a low frequency encoding parameter, performing encoding on the high band signal to obtain a high frequency encoding parameter, obtaining a synthesized high band signal, performing short-time post-filtering processing on the synthesized high band signal to obtain a short-time filtering signal, and calculating a high frequency gain based on the high band signal and the short-time filtering signal.

Abstract: A method for encoding an audio signal includes obtaining an ITD value of a current frame of an audio signal; obtaining a characteristic parameter of the current frame, wherein the characteristic parameter comprises at least one of a signal-to-noise ratio of the current frame or a peak feature of cross correlation coefficients of the current frame; determining, based on the characteristic parameter, whether to use the initial ITD value as the finalized ITD value of the current frame; and encoding the current frame based on the finalized ITD value of the current frame, wherein if the initial ITD value is determined as not used as the finalized ITD value of the current frame, the finalized ITD value of the current frame is the same as a finalized ITD value of a previous frame of the current frame.

Abstract: A method comprises determining a first modification weight according to linear spectral frequency (LSF) differences of the current frame and LSF differences of a previous frame of the current frame, when a signal characteristic of the current frame meets a preset modification condition, modifying the linear predictive parameter of the current frame according to the determined first modification weight, and coding the current frame according to the modified linear predictive parameter.

Abstract: An audio signal encoding method and device are provided. The method and device are used to encode an audio signal to obtain a bitstream representing the analog audio signal, in which a proper bit allocation for spectral coefficients can be performed.

Abstract: A method for encoding a high frequency signal includes determining a signal type of a high frequency signal of a current frame, smoothing and scaling time envelopes of the high frequency signal of the current frame and obtaining time envelopes of the high frequency signal of the current frame that require to be encoded when the high frequency signal of the current frame is a non-transient signal and a high frequency signal of the previous frame is a transient signal, and quantizing and encoding the time envelopes of the high frequency signal of the current frame that require to be encoded, and frequency information and signal type information of the high frequency signal of the current frame.

Abstract: A method for encoding an audio signal includes obtaining an ITD value of a current frame of an audio signal; obtaining a characteristic parameter of the current frame, wherein the characteristic parameter comprises at least one of a signal-to-noise ratio of the current frame or a peak feature of cross-correlation coefficients of the current frame; determining, based on the characteristic parameter, whether to use the initial ITD value as the finalized ITD value of the current frame; and encoding the current frame based on the finalized ITD value of the current frame, wherein if the initial ITD value is determined as not used as the finalized ITD value of the current frame, the finalized ITD value of the current frame is the same as a finalized ITD value of a previous frame of the current frame.

Abstract: A multi-channel signal encoding method includes determining a downmixed signal of a first channel signal and a second channel signal, determining an initial reverberation gain parameter of the first channel signal and the second channel signal, determining a target reverberation gain parameter of the first channel signal and the second channel signal based on a correlation between the first channel signal and the downmixed signal, a correlation between the second channel signal and the downmixed signal, and the initial reverberation gain parameter, quantizing the first channel signal and the second channel signal based on the downmixed signal and the target reverberation gain parameter, and writing a quantized first channel signal and a quantized second channel signal into a bitstream.

Abstract: A method comprises determining a first modification weight according to linear spectral frequency (LSF) differences of the current frame and LSF differences of a previous frame of the current frame when a signal characteristic of the current frame meets a preset modification condition, modifying the linear predictive parameter of the current frame according to the determined first modification weight, and coding the current frame according to the modified linear predictive parameter.

Abstract: The present disclosure discloses an inter-channel phase difference parameter encoding method, where a current frame is obtained; a signal type and a previous IPD parameter encoding scheme of a previous frame are obtained; a current IPD parameter encoding scheme is obtained at least based on the signal type of the previous frame and the previous IPD parameter encoding scheme; and an IPD parameter of the current frame is processed based on the current IPD parameter encoding scheme.