Multichannel signal coding method, encoder and computer-readable medium

Abstract

A multichannel signal encoding method, a multichannel signal decoding method, an encoder, and a decoder are provided. The encoding method includes: determining (310) a reduced signal of a first channel signal and a second channel signal into a multichannel signal, an initial reverberation gain parameter of the first channel signal and the second channel signal; determining (320) 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 reduced signal, a correlation between the second channel signal and the reduced signal, and the initial reverberation gain parameter; and quantizing (330) the first channel signal and the second channel signal based on the reduced signal and the target reverberation gain parameter, and recording a quantized first channel signal and a quantized second channel signal in a bitstream.The quality of a channel signal obtained after reverb processing can be improved depending on the encoding method, the decoding method, the encoder, and the decoder.

Description

1 / 78 MULTICHANNEL SIGNAL CODING METHOD, ENCODER AND COMPUTER-READABLE MEDIUM

[001] This application claims priority from Chinese Patent Application No. 201710205821.2, filed with the Chinese Patent Office on March 31, 2017, and entitled MULTI-CHANNEL SIGNAL ENCODING METHOD, MULTI-CHANNEL SIGNAL DECODING METHOD, ENCODER, AND DECODER, which is incorporated herein by reference in its entirety. TECHNICAL FIELD

[002] This application relates to the field of audio coding and, more specifically, to a multichannel signal coding method, a multichannel signal decoding method, an encoder, and a decoder. BACKGROUND

[003] As quality of life improves, people have increasing demands for high-quality audio. Compared to mono audio, stereo audio provides a sense of orientation and a sense of distribution for each acoustic source, and provides greater clarity, intelligibility, and sense of sound in the room. Therefore, stereo audio is very popular.

[004] Stereo processing technologies mainly include mid / side (MS) encoding, intensity stereo (IS) encoding, parametric stereo (PS) encoding, and similar technologies.

[005] In the state of the art, when PS encoding is used to encode a channel signal, one side of the encoder performs spatial parameter analysis on a plurality of channel signals to obtain gain parameters. Petition 870250082749, dated 09 / 15 / 2025, page 8 / 173 2 / 78 of reverberation and other spatial parameters of the plurality of channel signals and encodes the reverberation gain parameters and other spatial parameters of the plurality of channel signals, so that the decoder side can perform, based on the reverberation gain parameters of the channel signals during decoding, reverberation processing on the plurality of channel signals obtained by decoding, in order to improve auditory effects. However, in some cases, for example, when a correlation between a plurality of channel signals is relatively low, worse auditory effects are caused when reverberation processing is performed, based on reverberation gain parameters corresponding to the plurality of channel signals, on the plurality of channel signals obtained by decoding. SUMMARY

[006] This application provides a multichannel signal encoding method, a multichannel signal decoding method, an encoder and a decoder, to improve the quality of a channel signal.

[007] According to a first aspect, a multichannel signal encoding method is provided, wherein the method includes: determining a downmixed signal from a first channel signal and a second channel signal into a multichannel signal, an initial reverb gain parameter of the first channel signal and the second channel signal; determining a target reverb 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 Petition 870250082749, dated 09 / 15 / 2025, page 9 / 173 3 / 78 second channel signal and the downmixed signal and the initial reverb gain parameter; and quantize the first channel signal and the second channel signal based on the downmixed signal parameter and target reverb gain, and record a quantized first channel signal and a quantized second channel signal in a bitstream.

[008] In this application, when a target reverb gain parameter of a channel signal is being determined, a correlation between the channel signal and the downmixed signal is considered. In this way, a better processing effect can be obtained when reverb processing is performed on the channel signal based on the target reverb gain parameter, thus improving the quality of a channel signal obtained after reverb processing.

[009] The correlation between the first channel signal or the second channel signal and the downmixed signal can be determined based on the difference between the energy of the first channel signal or the energy of the second channel signal and the energy of the downmixed signal, or it can be determined based on a difference between an amplitude of the first channel signal or an amplitude of the second channel signal and an amplitude of the downmixed signal.

[0010] With reference to the first aspect, in some implementations of the first aspect, the first channel signal, the second channel signal, and the downmixed signal are channel signals obtained after normalization processing.

[0011] With reference to the first aspect, in some implementations of the first aspect, the determination of a target reverb gain parameter of the first Petition 870250082749, dated 09 / 15 / 2025, page 10 / 173 4 / 78 channel signal and 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 reverb gain parameter include: determining a target attenuation factor based on the correlation between the first channel signal and the downmixed signal and the correlation between the second channel signal and the downmixed signal; and adjusting the initial reverb gain parameter based on the target attenuation factor to obtain the target reverb gain parameter.

[0012] The initial reverb gain parameter of the channel signal can be flexibly adjusted based on the correlation value between the channel signal and the downmixed signal using the attenuation factor.

[0013] The correlations between the first channel signal, the second channel signal, and the downmixed signal can be conveniently measured using the energy of the channel signal; that is, the target attenuation factor can be conveniently determined by comparing the difference between the energy of the channel signal and the energy of the downmixed signal. Specifically, when the difference between the energy of the first channel signal or the energy of the second channel signal and the energy of the downmixed signal is relatively large (greater than a certain threshold), the correlation between the first channel signal and the downmixed signal and the correlation between the second channel signal and the downmixed signal can be considered relatively weak. In this case, a relatively large target attenuation factor can be determined. However, when the difference between the energy of the first channel signal or the energy of the second channel signal is relatively large, the correlation between the first channel signal and the downmixed signal can be considered relatively weak. Petition 870250082749, dated 09 / 15 / 2025, page 11 / 173 If the 5 / 78 channel and the downmixed signal energy are relatively small (less than the specified limit), the correlation between the first channel signal and the downmixed signal, and the correlation between the second channel signal and the downmixed signal, can be considered relatively strong. In this case, a relatively small target attenuation factor can be determined.

[0014] Determining a target attenuation factor based on the correlation between the first channel signal and the downmixed signal and the correlation between the second channel signal and the downmixed signal may be calculating the target attenuation factor based on the correlations between the channel signals and the downmixed signal, or it may be directly determining a predefined attenuation factor as the target attenuation factor after considering the correlations between the channel signals and the downmixed signal.

[0015] With reference to the first aspect, in some implementations of the first aspect, each of the first channel signal and the second channel signal includes a plurality of frequency boxes, and the determination of a target attenuation factor based on the correlation between the first channel signal and the downmixed signal and the correlation between the second channel signal and the downmixed signal includes: determining difference values ​​between the energy of the first channel signal and the energy of the downmixed signal in the plurality of frequency boxes and between the energy of the second channel signal and the energy of the downmixed signal in the plurality of frequency boxes; and determining the target attenuation factor based on the difference values.

[0016] The difference between the energy of the first signal Petition 870250082749, dated 09 / 15 / 2025, page 12 / 173 The difference between the energy of the first channel signal and the energy of the downmixed signal, and the difference between the energy of the second channel signal and the energy of the downmixed signal, can be conveniently determined by comparing the difference values ​​between the energy of the first channel signal and the energy of the downmixed signal in the plurality of frequency boxes, and the energy of the second channel signal and the energy of the downmixed signal in the plurality of frequency boxes, and the attenuation factor is further determined. Therefore, it is unnecessary to compare the differences between the energy of the first channel signal and the energy of the downmixed signal and the differences between the energy of the second channel signal and the energy of the downmixed signal in all frequency bands.

[0017] With reference to the first aspect, in some implementations of the first aspect, the determining difference values ​​between the energy of the first channel signal and the energy of the downmixed signal in the frequency plurality and between the energy of the second channel signal and the energy of the downmixed signal in the frequency plurality include: determining a first difference value between the energy of the first channel signal and the energy of the downmixed signal, wherein the first difference value indicates a sum of the absolute values ​​of the difference values ​​between the energy of the first channel signal and the energy of the downmixed signal in the frequency plurality; and determining a second difference value between the energy of the second channel signal and the energy of the downmixed signal, wherein the second difference value indicates a sum of the absolute values ​​of the difference values ​​between the energy of the second channel signal and the energy of the downmixed signal in the frequency plurality Petition 870250082749, dated 09 / 15 / 2025, page 13 / 173 7 / 78 of frequency boxes; and the determination of the target attenuation factor based on the difference values ​​includes: determination of the target attenuation factor based on a ratio between the first difference value and the second difference value.

[0018] Alternatively, the target attenuation factor can be determined directly based on the first difference value and the second difference value.

[0019] With reference to the first aspect, in some implementations of the first aspect, before determining the target attenuation factor based on the difference values, the method also includes: determining that the difference values ​​are greater than a predefined limit.

[0020] Only when the difference values ​​between the energy of the first channel signal and the energy of the downmixed signal in the frequency plurality and the energy of the second channel signal and the energy of the downmixed signal are relatively large, the target attenuation factor is determined and the initial reverb gain parameter is adjusted based on the target attenuation factor. When the difference values ​​are relatively small, the initial reverb gain parameter may not be adjusted, thus improving encoding efficiency.

[0021] When the difference values ​​between the energy of a plurality of channel signals and the energy of the downmixed signal are less than the preset limit, the initial reverb gain parameter of the plurality of channel signals can be directly determined as the target reverb gain parameter of the plurality of channel signals. Petition 870250082749, dated 09 / 15 / 2025, page 14 / 173 8 / 78

[0022] With reference to the first aspect, in some implementations of the first aspect, the energy of the downmixed signal is determined based on the energy of the first channel signal and the energy of the second channel signal.

[0023] The energy of the downmixed signal can be calculated using the energy of the first channel signal and the energy of the second channel signal, and a calculation process can be simplified without using the downmixed signal itself.

[0024] With reference to the first aspect, in some implementations of the first aspect, the target attenuation factor includes a plurality of attenuation factors, each of the plurality of attenuation factors corresponds to at least one sub-band of the multichannel signal, and any sub-band corresponds to only one attenuation factor.

[0025] When the target attenuation factor includes a plurality of attenuation factors, a reverberation gain parameter can be adjusted more flexibly based on the target attenuation factor.

[0026] With reference to the first aspect, in some implementations of the first aspect, each of the frequency bands in which the first channel signal and the second channel signal are located includes a first frequency band and a second frequency band, an attenuation factor corresponding to a sub-band in the first frequency band is less than or equal to an attenuation factor corresponding to a sub-band in the second frequency band, and a frequency in the first frequency band is less than a frequency in the second frequency band. Petition 870250082749, dated 09 / 15 / 2025, page 15 / 173 9 / 78

[0027] The reverberation gain parameters corresponding to a high-frequency sub-band and a low-frequency sub-band can be adjusted to different degrees by setting attenuation factors of different sizes for the reverberation gain parameters corresponding to the high-frequency sub-band and the low-frequency sub-band, and a better processing effect can be obtained during the reverberation process.

[0028] According to a second aspect, a multichannel signal encoding method is provided, wherein the method includes: determining a downmixed signal from a first channel signal and a second channel signal into a multichannel signal, an initial reverb gain parameter of the first channel signal and the second channel signal; determining identification information of the first channel signal and the second channel signal based on a correlation between the first channel signal and the downmixed signal, and a correlation between the second channel signal and the downmixed signal, wherein the identification information indicates a channel signal that is in the first channel signal and the second channel signal and whose initial reverb gain parameter needs to be adjusted;and quantize the first channel signal and the second channel signal based on the downmixed signal, the initial reverb gain parameter, and the identification information, and record a quantized first channel signal and a quantized second channel signal in a bitstream.

[0029] The correlation between the first channel signal or the second channel signal and the downmixed signal can be determined based on the difference between the energy of the first Petition 870250082749, dated 09 / 15 / 2025, page 16 / 173 10 / 78 channel signal or the power of the second channel signal and the power of the downmixed signal, or it can be determined based on a difference between the amplitude of the first channel signal or the amplitude of the second channel signal and the amplitude of the downmixed signal.

[0030] In this application, a channel signal whose initial reverb gain parameter needs to be adjusted can be determined based on the correlation between the channel signal and the downmixed signal, so that one side of the decoder can first adjust the initial reverb gain parameter of some channel signals and then perform reverb processing on those channel signals, thus improving the quality of a channel signal obtained after reverb processing.

[0031] With reference to the second aspect, in some implementations of the second aspect, the determination of the identification information of the first channel signal and the second channel signal based on a correlation between the first channel signal and the downmixed signal, and a correlation between the second channel signal and the downmixed signal includes: determining the identification information of the first channel signal and the second channel signal based on a correlation between the energy of the first channel signal and the energy of the downmixed signal and a correlation between the energy of the second channel signal and the energy of the downmixed signal.

[0032] The correlation between the first channel signal and the downmixed signal and the correlation between the second channel signal and the downmixed signal can be conveniently measured using the energy of the channel signals and the energy of the downmixed signal, so that a channel signal whose parameter of Petition 870250082749, dated 09 / 15 / 2025, page 17 / 173 The initial reverb gain needs to be adjusted, but this can be conveniently determined.

[0033] With reference to the second aspect, in some implementations of the second aspect, the determination of the identification information of the first channel signal and the second channel signal based on a correlation between the energy of the first channel signal and the energy of the downmixed signal and a correlation between the energy of the second channel signal and the energy of the downmixed signal includes: determining a first difference value and a second difference value, wherein the first difference value is a sum of the absolute values ​​of the difference values ​​between the energy of the first channel signal and the energy of the downmixed signal in a plurality of frequency boxes, and the second difference value is a sum of the absolute values ​​of the difference values ​​between the energy of the second channel signal and the energy of the downmixed signal in the plurality of frequency boxes;and determine the identification information of the first channel signal and the second channel signal based on the first difference value and the second difference value.

[0034] It should be understood that the energy values ​​of the first channel signal, the second channel signal, and the downmixed signal may be values ​​obtained after normalization processing.

[0035] The difference between the energy of the first channel signal and the energy of the downmixed signal, and the difference between the energy of the second channel signal and the energy of the downmixed signal, can be conveniently determined by comparing the energy difference values ​​of Petition 870250082749, dated 09 / 15 / 2025, page 18 / 173 12 / 78 first channel signal and the energy of the downmixed signal in the frequency plurality and the energy of the second channel signal and the energy of the downmixed signal in the frequency plurality, in order to determine a channel signal whose initial reverb gain parameter needs to be adjusted. Therefore, it is unnecessary to compare the differences between the energy of the first channel signal and the energy of the downmixed signal and the differences between the energy of the second channel signal and the energy of the downmixed signal in all frequency bands.

[0036] With reference to the second aspect, in some implementations of the second aspect, the determination of the identification information of the first channel signal and the second channel signal based on the first difference value and the second difference value includes: determining the larger difference value in the first difference value and in the second difference value as a target difference value; and determining the identification information based on the target difference value, wherein the identification information indicates a channel signal corresponding to the target difference value and the channel signal corresponding to the target difference value is a channel signal whose initial reverb gain parameter needs to be adjusted.

[0037] With reference to the second aspect, in some implementations of the second aspect, the method further includes: determining a target attenuation factor based on the first difference value and the second difference value, wherein the target attenuation factor is used to adjust an initial reverberation gain parameter of a target channel signal; and quantizing the target attenuation factor and recording a factor of Petition 870250082749, dated 09 / 15 / 2025, page 19 / 173 13 / 78 quantized target attenuation in the bitstream.

[0038] The initial reverb gain parameter of the channel signal can be flexibly adjusted based on the correlation value between the channel signal and the downmixed signal using the attenuation factor.

[0039] With reference to the second aspect, in some implementations of the second aspect, the target attenuation factor includes a plurality of attenuation factors, each of the plurality of attenuation factors corresponds to at least one sub-band of the target channel signal, and any sub-band corresponds to only one attenuation factor.

[0040] When the target attenuation factor includes a plurality of attenuation factors, a reverberation gain parameter can be adjusted more flexibly based on the target attenuation factor.

[0041] With reference to the second aspect, in some implementations of the second aspect, the target channel signal includes a first frequency band and a second frequency band, an attenuation factor corresponding to a sub-band in the first frequency band is less than or equal to an attenuation factor corresponding to a sub-band in the second frequency band, and a frequency in the first frequency band is less than the frequency in the second frequency band.

[0042] The reverberation gain parameters corresponding to a high-frequency sub-band and a low-frequency sub-band can be adjusted to different degrees by setting attenuation factors of different sizes for the reverberation gain parameters corresponding to the high-frequency sub-band and the low-frequency sub-band. Petition 870250082749, dated 09 / 15 / 2025, page 20 / 173 14 / 78 low frequency, and a better processing effect can be obtained during the reverb process.

[0043] With reference to the second aspect, in some implementations of the second aspect, the energy of the downmixed signal is determined based on the energy of the first channel signal and the energy of the second channel signal.

[0044] The energy of the downmixed signal is estimated or deduced using the energy of a plurality of channel signals, which can reduce the calculation.

[0045] According to a third aspect, a multichannel signal decoding method is provided, wherein the method includes: obtaining a bitstream; determining a downmixed signal of a first channel signal and a second channel signal into a multichannel signal, an initial reverberation gain parameter of the first channel signal and the second channel signal, and identification information of the first channel signal and the second channel signal based on the bitstream, wherein the identification information indicates a channel signal that is in the first channel signal and the second channel signal and whose initial reverberation gain parameter needs to be adjusted; determining, as a target channel signal based on the identification information, the channel signal that is in the first channel signal and the second channel signal and whose initial reverberation gain parameter needs to be adjusted; and adjusting the initial reverberation gain parameter of the target channel signal.

[0046] In this application, the channel signal whose initial reverb gain parameter needs to be adjusted can be determined using the identification information, and the Petition 870250082749, dated 09 / 15 / 2025, page 21 / 173 The 15 / 78 initial reverb gain parameter of the channel signal is adjusted before reverb processing is performed on the channel signal, thus improving the quality of a channel signal obtained after reverb processing.

[0047] With reference to the third aspect, in some implementations of the third aspect, the adjustment of an initial reverberation gain parameter of the target channel signal includes: determining a target attenuation factor; and adjusting the initial reverberation gain parameter of the target channel signal based on the target attenuation factor, to obtain a target reverberation gain parameter of the target channel signal.

[0048] The initial reverb gain parameter of the channel signal can be flexibly adjusted based on the correlation value between the channel signal and the downmixed signal using the attenuation factor.

[0049] With reference to the third aspect, in some implementations of the third aspect, the determination of a target attenuation factor includes: determining a predefined attenuation factor as the target attenuation factor.

[0050] A process for determining the target attenuation factor can be simplified by pre-configuring the attenuation factor, thereby improving decoding efficiency.

[0051] With reference to the third aspect, in some implementations of the third aspect, the determination of a target attenuation factor includes: obtaining the target attenuation factor based on the bit stream.

[0052] When the bit stream includes the factor of Petition 870250082749, dated 09 / 15 / 2025, page 22 / 173 16 / 78 target attenuation, the target attenuation factor can be obtained directly from the bit stream, and the process of determining the target attenuation factor can also be simplified, thus improving decoding efficiency.

[0053] With reference to the third aspect, in some implementations of the third aspect, the determination of a target attenuation factor includes: obtaining a level difference between channels between the first channel signal and the second channel signal of the bitstream; and determining the target attenuation factor based on the level difference between channels or determining the target attenuation factor based on the level difference between channels and the downmixed signal.

[0054] The target attenuation factor can be determined more flexibly and accurately based on the level difference between channels, the downmixed signal and the like, so that an initial reverb gain parameter of a channel signal can be adjusted more precisely based on the attenuation factor.

[0055] With reference to the third aspect, in some implementations of the third aspect, the target attenuation factor includes a plurality of attenuation factors, each of the plurality of attenuation factors corresponds to at least one sub-band of the target channel signal and any sub-band corresponds to only one attenuation factor.

[0056] When the target attenuation factor includes a plurality of attenuation factors, a reverberation gain parameter can be adjusted more flexibly based on the target attenuation factor.

[0057] With reference to the third aspect, in Petition 870250082749, dated 09 / 15 / 2025, page 23 / 173 17 / 78 In some implementations of the third aspect, the target channel signal includes a first frequency band and a second frequency band, an attenuation factor corresponding to a sub-band in the first frequency band is less than or equal to an attenuation factor corresponding to a sub-band in the second frequency band, and a frequency in the first frequency band is less than the frequency in the second frequency band.

[0058] The reverberation gain parameters corresponding to a high-frequency sub-band and a low-frequency sub-band can be adjusted to different degrees by setting attenuation factors of different sizes for the reverberation gain parameters corresponding to the high-frequency sub-band and the low-frequency sub-band, and a better processing effect can be obtained during the reverberation process.

[0059] According to a fourth aspect, an encoder is provided, and the encoder includes a module or unit configured to execute the method in the first aspect or in various implementations of the first aspect.

[0060] According to a fifth aspect, an encoder is provided, and the encoder includes a module or unit configured to execute the method in the second aspect or in various implementations of the second aspect.

[0061] According to a sixth aspect, a decoder is provided, and the decoder includes a module or unit configured to execute the method in the third aspect or in various implementations of the third aspect.

[0062] According to a seventh aspect, an encoder is provided. The encoder includes a memory and a Petition 870250082749, dated 09 / 15 / 2025, p. 24 / 173 18 / 78 processor, where memory is configured to store a program, the processor is configured to execute the program, and when the program is executed, the processor executes the method in the first aspect or in multiple implementations of the first aspect.

[0063] According to an eighth aspect, an encoder is provided. The encoder includes a memory and a processor, wherein the memory is configured to store a program, the processor is configured to execute the program, and when the program is executed, the processor executes the method in the second aspect or in various implementations of the second aspect.

[0064] According to a ninth aspect, a decoder is provided. The decoder includes a memory and a processor, where the memory is configured to store a program, the processor is configured to execute the program, and when the program is executed, the processor executes the method in the third aspect or in various implementations of the third aspect.

[0065] According to a tenth aspect, a computer-readable medium is provided, the computer-readable medium stores the program code to be executed by a device, and the program code includes an instruction used to execute the method in the first aspect or various implementations of the first aspect.

[0066] According to an eleventh aspect, a computer-readable medium is provided, the computer-readable medium stores the program code to be executed by a device, and the program code includes an instruction used to execute the method in the second aspect or several Petition 870250082749, dated 09 / 15 / 2025, page 25 / 173 19 / 78 implementations of the second aspect.

[0067] According to a twelfth aspect, a computer-readable medium is provided, the computer-readable medium stores the program code to be executed by a device, and the program code includes an instruction used to execute the method in the third aspect or in various implementations of the third aspect. BRIEF DESCRIPTION OF THE DRAWINGS

[0068] FIG. 1 is a schematic flowchart of encoding a left-channel signal and a right-channel signal in the state of the art; FIG. 2 is a schematic flowchart for decoding a left-channel signal and a right-channel signal in the state of the art; FIG. 3 is a schematic flowchart of a multichannel signal encoding method according to one embodiment of this application; FIG. 4 is a schematic flowchart of a multichannel signal encoding method according to one embodiment of this application; FIG. 5 is a schematic flowchart of a multichannel signal decoding method according to one embodiment of this application; FIG. 6 is a schematic flowchart of a multichannel signal encoding method according to one embodiment of this application; FIG. 7 is a schematic flowchart of a multichannel signal decoding method according to one embodiment of this application; FIG. 8 is a schematic block diagram of a Petition 870250082749, dated 09 / 15 / 2025, page 26 / 173 20 / 78 encoder according to a modality of this request; FIG. 9 is a schematic block diagram of an encoder according to one embodiment of this application; FIG. 10 is a schematic block diagram of a decoder according to one embodiment of this application; FIG. 11 is a schematic block diagram of an encoder according to an embodiment of this application; FIG. 12 is a schematic block diagram of an encoder according to an embodiment of this application; and FIG. 13 is a schematic block diagram of a decoder according to one embodiment of this application. DESCRIPTION OF THE MODALITIES

[0069] The technical solutions of this application are described below with reference to the attached drawings. To better understand a multichannel signal encoding method and a multichannel signal decoding method in the embodiments of this application, the following briefly describes a multichannel signal encoding method and a multichannel signal decoding method in the prior art with reference to FIG. 1 and FIG. 2.

[0070] FIG. 1 shows a prior art encoding process for a left-channel signal and a right-channel signal. The encoding process shown in FIG. 1 specifically includes the following steps.

[0071] 110. Perform spatial parameter analysis and downmixing processing on a left-channel signal (represented by L in the figure) and on a right-channel signal (represented by R in the figure).

[0072] Specifically, step 110 specifically includes: performing spatial parameter analysis on Petition 870250082749, dated 09 / 15 / 2025, page 27 / 173 21 / 78 left channel signal and right channel signal to obtain a spatial parameter of the left channel signal and a spatial parameter of the right channel signal; and perform downmixing processing on the left channel signal and the right channel signal to obtain a downmixed signal (where the downmixed signal obtained after downmixing processing is a mono audio signal, and the two original audio signal channels are converted into one audio signal channel through downmixing processing).

[0073] The spatial parameter (also called the spatial detection parameter) includes an inter-channel correlation (Inter-channel Coherent, IC), an inter-channel level difference (Inter-channel Level Difference, ILD), an inter-channel time difference (Inter-channel Time Difference, ITD), an inter-channel phase difference (Inter-channel Phase Difference, IPD), and the like.

[0074] IC describes cross-correlation between channels or coherence. This parameter determines the detection of a sound field range and can improve the spatial sense and stability of an audio signal. ILD is used to distinguish a horizontal direction angle of a stereo source and describes an intensity difference between channels; this parameter affects the frequency components of an entire spectrum. ITD and IPD are spatial parameters that represent the horizontal directions of a sound source. They describe time and phase differences between channels. These parameters primarily affect frequency components below 2 kHz. For two-channel signals, ITD can represent a time delay between a left-channel signal and a right-channel signal of a stereo system, and Petition 870250082749, dated 09 / 15 / 2025, page 28 / 173 22 / 78 IPD can represent a similarity of the waveform of the left channel signal and the right channel signal of the stereo after time alignment. ILD, ITD, and IPD can determine the human ear's detection of a sound source location, effectively determine a sound field location, and play an important role in restoring the stereo signal.

[0075] 120. Encode the downmixed signal to obtain a bitstream.

[0076] 130. Encode the spatial parameters to obtain a bitstream.

[0077] 140. Multiplex the bitstream obtained by encoding the downmixed signal and the bitstream obtained by encoding the spatial parameters to obtain a bitstream.

[0078] The bit stream obtained through encoding can be stored or transmitted to a decoder-side device.

[0079] FIG. 2 shows a decoding process for a left-channel signal and a right-channel signal in the state of the art. The decoding process shown in FIG. 2 specifically includes the following steps.

[0080] 210. Demultiplex a bit stream to obtain separately a bit stream obtained by encoding a downmixed signal and a bit stream obtained by encoding a spatial parameter.

[0081] 220. Decode the bit streams to obtain a downmixed signal of a left-channel signal and a right-channel signal, a spatial parameter of the left-channel signal and a spatial parameter of the right-channel signal. Petition 870250082749, dated 09 / 15 / 2025, page 29 / 173 23 / 78

[0082] The spatial parameters include an IC of the left channel signal and the right channel signal.

[0083] 230. Obtain a decorrelation signal based on a downmixed signal and the spatial parameter of a current frame.

[0084] The left channel signal and the right channel signal are obtained based on a decoded downmixed signal and the current frame decorrelation signal.

[0085] 240. Finally, obtain the left-channel and right-channel output signals (representatively shown by L' and R' in FIG. 2) based on the spatial parameters, the left-channel signal, and the right-channel signal.

[0086] It should be understood that the left channel signal and the right channel signal (respectively represented by L' and R' in FIG. 2) in step 240 are obtained by decoding and may be distorted to some extent compared with a left channel signal and a right channel signal that are encoded on the encoder side.

[0087] Specifically, the downmixed signal can be filtered and then a channel correlation parameter is used to correct a filtered downmixed signal to obtain a decorrelation signal.

[0088] One objective of generating the decorrelation signal is to improve the reverberation sensation of a stereo signal ultimately generated on the decoder side, and to increase the sound field width of the stereo signal, so that an output audio signal is smoother and fuller in terms of auditory sense. The reverberation sensation is essentially a delay effect, like reflecting and refracting a signal. Petition 870250082749, dated 09 / 15 / 2025, page 30 / 173 24 / 78 original audio is retransmitted differently, and then the reflected and refracted audio signals are superimposed onto the original audio signal to enter the human ear.

[0089] In the prior art, after obtaining the IC, no correlation between different channel signals is considered in order to adaptively adjust the IC. In this case, when reverb processing is performed on the channel signal based on the previously obtained IC, a relatively poor auditory effect may be caused. For example, when a correlation between different channel signals is relatively low, if the previously obtained IC is still used to correct a decorrelation signal, and then the decorrelation signal is used to perform the same reverb processing on the different channel signals, the quality of a channel signal finally emitted by the decoder side is relatively poor.In other words, since the difference between signals from different channels is relatively large, if reverb processing is performed on signals from different channels, even using the relatively large IC-corrected decorrelation signal, the reverb effect of the channel signal will not be increased, but the output channel signal may be distorted.

[0090] Therefore, the modalities of this application provide a method for encoding or decoding a multichannel signal. In this method, a reverb gain parameter can be correspondingly adjusted based on a correlation between different channel signals, and a decorrelation signal is corrected using an adjusted reverb gain parameter. Then, reverb processing is performed on different channel signals, Petition 870250082749, dated 09 / 15 / 2025, page 31 / 173 25 / 78 using the decorrelation signal. In this way, when reverb processing is performed on different channel signals, the correlation between different channel signals is considered, so that the quality of an output channel signal is better.

[0091] FIG. 3 is a schematic flowchart of a multichannel signal encoding method according to an embodiment of this application. The method in FIG. 3 can be implemented by an encoder-side device or an encoder. The method shown in FIG. 3 includes the following steps.

[0092] 310. Determine a downmixed signal of a first channel signal and a second channel signal into a multichannel signal, an initial reverb gain parameter of the first channel signal and of the second channel signal.

[0093] It should be understood that, in this embodiment of this application, a sequence for determining the downmixed signal and determining the initial reverberation gain parameter is not limited, and the downmixed signal and the initial reverberation gain parameter may be determined simultaneously or successively.

[0094] The initial reverberation gain parameter can be a reverberation gain parameter obtained after spatial parameter analysis is performed on the first channel signal and the second channel signal.

[0095] Specifically, the downmixed signal can be obtained by performing downmixing processing on a plurality of channel signals. A spatial parameter of the first channel signal and a spatial parameter of the second Petition 870250082749, dated 09 / 15 / 2025, page 32 / 173 26 / 78 channel signals are obtained through the analysis of spatial parameters in the first channel signal and the second channel signal, where spatial parameters include the initial reverberation gain parameter of the first channel signal and the second channel signal.

[0096] It should be understood that the first channel signal and the second channel signal may correspond to the same spatial parameter and, correspondingly, the first channel signal and the second channel signal may also correspond to the same initial reverberation gain parameter. That is, the spatial parameter of the first channel signal and the spatial parameter of the second channel signal may be the same, and the initial reverberation gain parameter of the first channel signal and the second channel signal may also be the same.

[0097] Furthermore, assuming that each of the first channel signal and the second channel includes 10 sub-bands and each sub-band corresponds to a reverb gain parameter, the reverb gain parameters corresponding to the sub-bands, whose index values ​​are the same, of the first channel signal and the second channel signal may be the same.

[0098] In addition, the first channel signal, the second channel signal, and the downmixed signal may be channel signals obtained after normalization processing.

[0099] 320. Determine a target reverb gain parameter for 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 parameter of Petition 870250082749, dated 09 / 15 / 2025, page 33 / 173 27 / 78 initial reverb gain.

[00100] Optionally, the correlation between the first channel signal or the second channel signal and the downmixed signal can be determined based on the difference between the energy of the first channel signal or the energy of the second channel signal and the energy of the downmixed signal, or it can be determined based on the difference between an amplitude of the first channel signal or an amplitude of the second channel signal and an amplitude of the downmixed signal.

[00101] Specifically, when the difference between the energy or amplitude of the first channel signal and the energy or amplitude of the downmixed signal is relatively small, the correlation between the first channel signal and the downmixed signal can be considered relatively large. When the difference between the energy or amplitude of the first channel signal and the energy or amplitude of the downmixed signal is relatively large, the correlation between the first channel signal and the downmixed signal can be considered relatively small.

[00102] The difference between the energy of the first channel signal or the energy of the second channel signal and the energy of the downmixed signal can specifically be a difference value between the energy of the first channel signal or the energy of the second channel signal and the energy of the downmixed signal. Similarly, the difference between the amplitude of the first channel signal or the amplitude of the second channel signal and the amplitude of the downmixed signal can specifically be a difference value between the amplitude of the first channel signal or the amplitude of the second channel signal and the amplitude of the downmixed signal. Petition 870250082749, dated 09 / 15 / 2025, page 34 / 173 28 / 78

[00103] Furthermore, the correlation between the first channel signal or the second channel signal and the downmixed signal may alternatively refer to a difference between a phase, a period or similar of the first channel signal or the second channel signal and a phase, a period or similar of the downmixed signal.

[00104] 330. Quantize the first channel signal and the second channel signal based on the downmixed signal and the target reverb gain parameter, and record a quantized first channel signal and a quantized second channel signal in a bitstream.

[00105] It should be understood that when the multichannel signal has more than two channel signals, for example, when the multichannel signal includes the first channel signal, the second channel signal, a third channel signal and a fourth channel signal, the first channel signal and the second channel signal can be processed using the method in FIG. 3, and the third channel signal and the fourth channel signal are also processed using the method in FIG. 3.

[00106] In the present application, when a target reverb gain parameter of a channel signal is being determined, a correlation between the channel signal and the downmixed signal is considered. In this way, a better processing effect can be obtained when reverb processing is performed on the channel signal based on the target reverb gain parameter, thus improving the quality of a channel signal obtained after reverb processing.

[00107] Optionally, in one embodiment, the determination of a target reverberation gain parameter Petition 870250082749, dated 09 / 15 / 2025, page 35 / 173 29 / 78 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 reverb gain parameter includes: determining a target attenuation factor based on the correlation between the first channel signal and the downmixed signal and the correlation between the second channel signal and the downmixed signal; and adjusting the initial reverb gain parameter based on the target attenuation factor, to obtain the target reverb gain parameter.

[00108] Specifically, determining a target attenuation factor based on the correlation between the first channel signal and the downmixed signal and the correlation between the second channel signal and the downmixed signal can be done by calculating the target attenuation factor based on the correlations between the channel signals and the downmixed signal, or it can be done by directly determining a predefined attenuation factor as the target attenuation factor after considering the correlations between the channel signals and the downmixed signal.

[00109] The initial reverb gain parameter of the channel signal can be flexibly adjusted based on the correlation value between the channel signal and the downmixed signal using the attenuation factor.

[00110] For example, when the correlation between the first channel signal and the downmixed signal and the correlation between the second channel signal and the downmixed signal are relatively large (in this case, it can also be considered that the first channel signal is relatively similar to the second channel signal), a target attenuation factor with a relatively small value can be determined. Petition 870250082749, dated 09 / 15 / 2025, page 36 / 173 30 / 78 However, when the correlation between the first channel signal and the downmixed signal and the correlation between the second channel signal and the downmixed signal are relatively small (in this case, it can also be considered that the first channel signal is relatively different from the second channel signal), a target attenuation factor with a relatively large value can be determined.

[00111] In some embodiments, the correlations between the channel plurality signals and the downmixed signal may refer to differences between the energy of the channel plurality signals and the energy of the downmixed signal, or differences between the amplitudes of the channel plurality signals and the amplitude of the downmixed signal. The differences between the energy of the channel plurality signals and the energy of the downmixed signal may specifically be difference values ​​between the energy of the channel plurality signals and the energy of the downmixed signal. Similarly, the differences between the amplitudes of the channel plurality signals and the amplitude of the downmixed signal may specifically be difference values ​​between the amplitudes of the channel plurality signals and the amplitude of the downmixed signal.Furthermore, the correlations between the channel plurality signals and the downmixed signal may alternatively refer to differences between the phases, periods, or similar of the channel plurality signals and the phase, period, or similar of the downmixed signal.

[00112] In some embodiments, the correlation between the first channel signal or the second channel signal and the downmixed signal can be determined based on the difference between the energy of the first channel signal or the energy of the second channel signal and the energy of the downmixed signal, and also the Petition 870250082749, dated 09 / 15 / 2025, page 37 / 173 31 / 78 target attenuation factor is determined.

[00113] The correlation between the first channel signal and the downmixed signal and the correlation between the second channel signal and the downmixed signal can be conveniently measured using the energy of the channel signals and the energy of the downmixed signal, i.e., the target attenuation factor can be conveniently determined by comparing the difference between the energy of the first channel signal or the energy of the second channel signal and the energy of the downmixed signal.

[00114] Optionally, in one embodiment, the first channel signal and the second channel signal include a plurality of frequency boxes and the determination of a target attenuation factor based on the correlation between the first channel signal and the downmixed signal and the correlation between the second channel signal and the downmixed signal includes: determining difference values ​​between the energy of the first channel signal and the energy of the downmixed signal in the plurality of frequency boxes and between the energy of the second channel signal and the energy of the downmixed signal in the plurality of frequency boxes; and determining the target attenuation factor based on the difference values.

[00115] The difference values ​​between the energy of the first channel signal and the energy of the downmixed signal in a plurality of frequency boxes can be the difference values ​​between the energy of the first channel signal and the energy of the downmixed signal in a plurality of the same frequency boxes. For example, the first channel signal includes three frequency boxes (a first frequency channel number, a second frequency channel number, and a third frequency channel number). In this case, the Petition 870250082749, dated 09 / 15 / 2025, p. 38 / 173 32 / 78 difference values ​​between the energy of the first channel signal and the energy of the downmixed signal in the three frequency boxes are specifically a difference value between the first channel signal and the downmixed signal in the first frequency channel number, a difference value between the first channel signal and the downmixed signal in the second frequency channel number, and a difference value between the first channel signal and the downmixed signal in the third frequency channel number.

[00116] Similarly, the difference values ​​between the energy of the second channel signal and the energy of the downmixed signal in the plurality of frequency boxes can be difference values ​​between the energy of the second channel signal and the energy of the downmixed signal in the plurality of the same frequency boxes.

[00117] Optionally, the difference values ​​between the energy of the first channel signal and the energy of the downmixed signal in the frequency plurality can be a sum of the absolute values ​​of the difference values ​​between the energy of the first channel signal and the energy of the downmixed signal in the frequency plurality. Similarly, the difference values ​​between the energy of the second channel signal and the energy of the downmixed signal in the frequency plurality can be a sum of the absolute values ​​of the difference values ​​between the energy of the second channel signal and the energy of the downmixed signal in the frequency plurality.

[00118] It should be understood that the energy values ​​of the first channel signal, the second channel signal, and the downmixed signal can be values ​​obtained after the Petition 870250082749, dated 09 / 15 / 2025, page 39 / 173 33 / 78 normalization processing.

[00119] The difference between the energy of the first channel signal and the energy of the downmixed signal and the difference between the energy of the second channel signal and the energy of the downmixed signal can be conveniently determined by comparing the difference values ​​between the energy of the first channel signal and the energy of the downmixed signal in the plurality of frequency boxes and the energy of the second channel signal and the energy of the downmixed signal in the plurality of frequency boxes, and the attenuation factor is further determined. Therefore, it is unnecessary to compare the differences between the energy of the first channel signal and the energy of the downmixed signal and the differences between the energy of the second channel signal and the energy of the downmixed signal in all frequency bands.

[00120] Optionally, in one embodiment, the determination of the difference values ​​between the energy of the first channel signal and the energy of the downmixed signal in the frequency plurality and between the energy of the second channel signal and the energy of the downmixed signal in the frequency plurality includes: determining a first difference value between the energy of the first channel signal and the energy of the downmixed signal, wherein the first difference value indicates a sum of the absolute values ​​of the difference values ​​between the energy of the first channel signal and the energy of the downmixed signal in the frequency plurality; determining a second difference value between the energy of the second channel signal and the energy of the downmixed signal, wherein the second difference value indicates a sum of the absolute values ​​of the difference values ​​between the Petition 870250082749, dated 09 / 15 / 2025, page 40 / 173 34 / 78 energy of the second channel signal and the energy of the downmixed signal in the frequency plurality; and determine the target attenuation factor based on the first difference value and the second difference value.

[00121] Determining the target attenuation factor based on the first difference value and the second difference value may include: determining the target attenuation factor based on a ratio between the first difference value and the second difference value.

[00122] Specifically, when the first channel signal is a left-channel signal and the second channel signal is a right-channel signal, the first difference value and the second difference value can be calculated according to the following formula: M2 diff_l_h = y \mag _ Z[fe ] - mag _ dmx[k]\ k=Ml ( ]_ ) M2 diff _r _h= |w?ag_ r[Â] - mag _dmy\k^ (2) Where diff_l_h is the first difference value, diff_r_h is the second difference value, a frequency band of each of the left channel signal and the right channel signal includes a high-frequency part and a low-frequency part, M1 is the initial frequency channel number of the high-frequency part, M2 is the final frequency channel number of the low-frequency part, _L\k \ energy or an amplitude value of the left channel signal at a frequency channel number between M1 and M2, mag \ energy or an amplitude value of the right channel signal at a frequency channel number with an index k between M1 and M2, mag \ dm\ k \ energy or an amplitude value of the downmixed signal at a frequency channel number with an index k between M1 and M2, mag \ dm\ k \ pOCje is obtained through calculation Petition 870250082749, dated 09 / 15 / 2025, p. 41 / 173 35 / 78 using the downmixed signal itself, or it can be obtained through calculation based on the energy or amplitude values ​​of the left channel signal and the right channel signal.

[00123] When the target attenuation factor is being determined based on the first difference value and the second difference value, the ratio between the first difference value and the second difference value can be directly determined as the target attenuation factor. For example, the first difference value is a, and the second difference value is b. When a < b, a / b is determined as the target attenuation factor, or when a > b, b / a is determined as the target attenuation factor. Furthermore, after the target attenuation factor is determined based on the first difference value and the second difference value, some smoothing processing can be performed on the target attenuation factor and an attenuation factor from a previous frame, and a target attenuation factor obtained after the smoothing processing is used to further adjust the initial reverb gain parameter of the channel signal plurality.

[00124] Optionally, in one embodiment, before the target attenuation factor is determined based on previous difference values, the method in FIG. 3 further includes: determining that the difference values ​​are greater than a predefined limit.

[00125] It should be understood that the difference values ​​being greater than the predefined limit here may mean that the difference values ​​between the energy of the first channel signal and the energy of the downmixed signal in the frequency plurality and the energy of the second channel signal and the energy of the downmixed signal are greater Petition 870250082749, dated 09 / 15 / 2025, page 42 / 173 36 / 78 which may mean that the same predefined limit, or they may mean that the difference between the energy of the first channel signal and the energy of the downmixed signal is greater than the first predefined limit, and the difference between the energy of the second channel signal and the energy of the downmixed signal is greater than a second predefined limit.

[00126] Only when the difference values ​​between the energy of the first channel signal and the energy of the downmixed signal in the frequency plurality and the energy of the second channel signal and the energy of the downmixed signal are relatively large, the target attenuation factor is determined and the initial reverb gain parameter is adjusted based on the target attenuation factor. When the difference values ​​are relatively small, the initial reverb gain parameter may not be adjusted, thus improving encoding efficiency.

[00127] For example, when the difference value between the energy of the first channel signal and the energy of the downmixed signal is greater than M (where M is between 0.5 and 1) times the energy of the first channel signal, it can be considered that the difference value between the energy of the first channel signal and the energy of the downmixed signal is greater than the preset limit. In this case, the preset limit is M times the energy of the first channel signal. Alternatively, when a ratio of the difference value between the energy of the first channel signal and the energy of the downmixed signal to the energy of the first channel signal is greater than M, it can also be considered that the difference value between the energy of the first channel signal and the energy of the downmixed signal is greater than the preset limit. Petition 870250082749, dated 09 / 15 / 2025, page 43 / 173 37 / 78

[00128] When the difference values ​​between the energy of a plurality of channel signals and the energy of the downmixed signal are less than the preset limit, the initial reverb gain parameter of the plurality of channel signals can be directly determined as the target reverb gain parameter of the plurality of channel signals.

[00129] Optionally, in one embodiment, the energy of the downmixed signal is determined based on the energy of the first channel signal and the energy of the second channel signal.

[00130] The energy of the downmixed signal can be calculated using the energy of the first channel signal and the energy of the second channel signal, and a calculation process can be simplified without using the downmixed signal itself.

[00131] Certainly, in this modality of this application, the energy of the downmixed signal can alternatively be calculated directly based on the downmixed signal itself.

[00132] Optionally, in one embodiment, the target attenuation factor includes a plurality of attenuation factors, each of the plurality of attenuation factors corresponding to at least one sub-band of the multichannel signal, and any sub-band corresponding to only one attenuation factor.

[00133] For example, the sub-band indices included in each of the first channel signal and the second channel signal are from 0 to 9. Both the first channel signal and the second channel signal include 10 reverb gain parameters, each sub-band corresponds to a reverb gain parameter, the target attenuation factor includes Petition 870250082749, dated 09 / 15 / 2025, page 44 / 173 38 / 78 five attenuation factors and each attenuation factor corresponds to two sub-bands; or the target attenuation factor includes 10 attenuation factors and each attenuation factor corresponds to one sub-band.

[00134] Furthermore, when the target attenuation factor includes a plurality of attenuation factors, a reverberation gain parameter can be adjusted more flexibly based on the target attenuation factor. For example, reverberation gain parameters corresponding to subbands with indices from 0 to 4 of a plurality of channel signals need to be slightly adjusted, but reverberation gain parameters corresponding to subbands with indices from 5 to 9 of a channel signal need to be considerably adjusted. In this case, relatively small attenuation factors can be set for the reverberation gain parameters corresponding to the subbands with indices from 0 to 4, and relatively large attenuation factors are set for the reverberation gain parameters corresponding to the subbands with indices from 5 to 9.

[00135] Optionally, in one embodiment, each of the first channel signal and the second channel signal (where a frequency band occupied by the first channel signal and a frequency band occupied by the second channel signal are the same) includes a first frequency band and a second frequency band, an attenuation factor corresponding to a sub-band in the first frequency band is less than or equal to an attenuation factor corresponding to a sub-band in the second frequency band, and a frequency of the first frequency band. Petition 870250082749, dated 09 / 15 / 2025, page 45 / 173 39 / 78 is lower than a frequency in the second frequency band.

[00136] For example, each of the frequency bands in which the first channel signal and the second channel signal are located includes a low-frequency portion and a high-frequency portion, and the target attenuation factor includes a plurality of attenuation factors. The low-frequency portion corresponds to at least one attenuation factor, the high-frequency portion corresponds to at least one attenuation factor, and the attenuation factor corresponding to the low-frequency portion is less than the attenuation factor corresponding to the high-frequency portion.

[00137] The reverberation gain parameters corresponding to a high-frequency sub-band and a low-frequency sub-band can be adjusted to different degrees by setting attenuation factors of different sizes for the reverberation gain parameters corresponding to the high-frequency sub-band and the low-frequency sub-band, and a better processing effect can be obtained during the reverberation process.

[00138] FIG. 4 is a schematic flowchart of a multichannel signal coding method according to an embodiment of this application. In FIG. 4, the channel signals include a left channel signal and a right channel signal, and a process for coding the left channel signal and the right channel signal specifically includes the following steps.

[00139] 410. Calculate a spatial parameter of the left channel signal and a spatial parameter of the right channel signal. Petition 870250082749, dated 09 / 15 / 2025, page 46 / 173 40 / 78

[00140] The spatial parameters include the initial reverberation gain parameter of the left channel signal and the right channel signal, and another spatial parameter.

[00141] 420. Perform downmixing processing on the left channel signal (represented by L in the figure) and on the right channel signal (represented by R in the figure) to obtain a downmixed signal.

[00142] 430. Determine the difference values ​​between the energy of the left-channel signal and the energy of the downmixed signal, and between the energy of the right-channel signal and the energy of the downmixed signal.

[00143] Specifically, each of the left channel signal and the right channel signal can be divided into a high-frequency part and a low-frequency part, and the difference values ​​between the energy of the left channel signal and the energy of the downmixed signal and between the energy of the right channel signal and the energy of the downmixed signal in the high-frequency part are determined as the difference values ​​between the energy of the left channel signal and the energy of the downmixed signal and between the energy of the right channel signal and the energy of the downmixed signal.

[00144] 440. Adjust the reverb gain parameters of the left and right channel signals based on the difference values ​​between the left channel signal energy and the downmixed signal energy, and between the right channel signal energy and the downmixed signal energy.

[00145] Specifically, one side of the encoder can determine a target attenuation factor based on the difference values ​​between the left channel signal energy and the Petition 870250082749, dated 09 / 15 / 2025, page 47 / 173 41 / 78 downmixed signal energy and between the right channel signal energy and the downmixed signal energy, and adjust the reverb gain parameters of the left channel signal and the right channel signal based on the target attenuation factor.

[00146] 450. Quantize the downmixed signal, adjust the reverb gain parameters and another spatial parameter to obtain a bitstream.

[00147] FIG. 5 is a schematic flowchart of a multichannel signal decoding method according to an embodiment of this application. In FIG. 5, the channel signals include a left-channel signal and a right-channel signal. In FIG. 5, the bitstream generated by encoding in the encoding method in FIG. 4 can be decoded. A decoding process in FIG. 5 specifically includes the following steps:

[00148] 510. Obtain a bitstream of the left-channel and right-channel signals.

[00149] 520. Decode the bitstream to obtain a downmixed signal.

[00150] 530. Decode the bit stream to obtain spatial parameters of the left-channel signal and the right-channel signal.

[00151] The spatial parameter includes a reverberation gain parameter adjusted by one side of the encoder, that is, the encoder side encodes the adjusted reverberation gain parameter. In this way, after decoding the bitstream, one side of the decoder obtains the reverberation gain parameter adjusted by the encoder side.

[00152] Steps 520 and 530 are not executed in a Petition 870250082749, dated 09 / 15 / 2025, page 48 / 173 42 / 78 sequence and can be executed simultaneously.

[00153] 540. Perform subsequent processing (e.g., soft filtering) on ​​the spatial parameters obtained by decoding.

[00154] 550. Obtain a decorrelation signal based on the downmixed signal and the reverb gain parameter that are obtained by decoding (where the reverb gain parameter is the reverb gain parameter adjusted by the encoder side).

[00155] 560. Perform upmixing processing based on the spatial parameters and the downmixed signal processed in step 540 to obtain the left channel signal and the right channel signal.

[00156] 570. Perform reverb processing separately on the left channel signal and the right channel signal, based on the decorrelation signal.

[00157] In the method shown in FIG. 5, the reverb gain parameter on which reverb processing is based on the left channel signal and the right channel signal was adjusted based on the correlations between the left channel signal and the downmixed signal and between the right channel signal and the downmixed signal. In this way, the corresponding reverb processing can be performed based on the difference between the left channel signal and the right channel signal, thus improving the quality of a channel signal obtained after reverb processing.

[00158] In the encoding method in FIG. 3, the encoder side determines whether an initial reverb gain parameter of a channel signal needs to be Petition 870250082749, dated 09 / 15 / 2025, page 49 / 173 43 / 78 adjusted. If the initial reverb gain parameter of the channel signal needs to be adjusted, the encoder side adjusts the initial reverb gain parameter of the channel signal and encodes an adjusted reverb gain parameter, so that the decoder side directly performs the reverb process based on a reverb gain parameter obtained by decoding.

[00159] In fact, the encoder side can alternatively only determine whether the initial reverb gain parameter of the channel signal needs to be adjusted. If the initial reverb gain parameter of the channel signal needs to be adjusted, the encoder side sends the corresponding indication information to the decoder side. After receiving the indication information, the decoder side adjusts the initial reverb gain parameter of the channel signal.

[00160] FIG. 6 is a schematic flowchart of a multichannel signal coding method according to an embodiment of this application. The method in FIG. 6 includes the following steps.

[00161] 610. Determine a downmixed signal of a first channel signal and a second channel signal into a multichannel signal, an initial reverb gain parameter of the first channel signal and of the second channel signal.

[00162] Specifically, the downmixed signal can be obtained by performing downmixing processing on the first channel signal and the second channel signal, and the spatial parameters are obtained through spatial parameter analysis on the first channel signal and the second channel signal. Petition 870250082749, dated 09 / 15 / 2025, page 50 / 173 44 / 78 channel, where the spatial parameters include the initial reverberation gain parameter of the first channel signal and the second channel signal.

[00163] It should be understood that the downmixed signal and the initial reverb gain parameter can be determined simultaneously or successively.

[00164] It should be understood that the first channel signal and the second channel signal may correspond to the same spatial parameter and, specifically, the first channel signal and the second channel signal also correspond to the same initial reverberation gain parameter. That is, a spatial parameter of the first channel signal and a spatial parameter of the second channel signal are the same, and the initial reverberation gain parameter of the first channel signal and the second channel signal are the same.

[00165] Furthermore, assuming that each of the first channel signal and the second channel includes 10 sub-bands and each sub-band corresponds to a reverb gain parameter, the reverb gain parameters corresponding to the sub-bands, whose index values ​​are the same, of the first channel signal and the second channel signal may be the same.

[00166] 620. Determine the identification information of the first channel signal and the second channel signal based on a correlation between the first channel signal and the downmixed signal, and a correlation between the second channel signal and the downmixed signal, where the identification information indicates a channel signal that is in the first channel signal and the second channel signal and whose initial reverb gain parameter needs Petition 870250082749, dated 09 / 15 / 2025, page 51 / 173 45 / 78 needs to be adjusted.

[00167] Optionally, the correlation between the first channel signal or the second channel signal and the downmixed signal can be determined based on the difference between the energy of the first channel signal or the energy of the second channel signal and the energy of the downmixed signal, or it can be determined based on the difference between an amplitude of the first channel signal or an amplitude of the second channel signal and an amplitude of the downmixed signal.

[00168] Specifically, when the difference between the energy or amplitude of the first channel signal and the energy or amplitude of the downmixed signal is relatively small, the correlation between the first channel signal and the downmixed signal can be considered relatively large. When the difference between the energy or amplitude of the first channel signal and the energy or amplitude of the downmixed signal is relatively large, the correlation between the first channel signal and the downmixed signal can be considered relatively small.

[00169] The difference between the energy of the first channel signal or the energy of the second channel signal and the energy of the downmixed signal can specifically be a difference value between the energy of the first channel signal or the energy of the second channel signal and the energy of the downmixed signal. Similarly, the difference between the amplitude of the first channel signal or the amplitude of the second channel signal and the amplitude of the downmixed signal can specifically be a difference value between the amplitude of the first channel signal or the amplitude of the second channel signal and the amplitude of the downmixed signal. Petition 870250082749, dated 09 / 15 / 2025, page 52 / 173 46 / 78 1. Furthermore, the correlation between the first channel signal or the second channel signal and the downmixed signal may alternatively refer to a difference between a phase, a period, or the like of the first channel signal or the second channel signal and a phase, a period, or the like of the downmixed signal.

[00170] The first channel signal, the second channel signal, and the downmixed signal can be channel signals obtained after normalization processing.

[00171] Specifically, the identification information may indicate that the first channel signal or the second channel signal is a channel signal whose initial reverb gain parameter needs to be adjusted, or it may indicate that the first channel signal and the second channel signal are channel signals whose initial reverb gain parameters need to be adjusted, or it may indicate that a reverb gain parameter does not need to be adjusted for either the first channel signal or the second channel signal.

[00172] In some embodiments, the identification information may indicate, using a value of an identifier field, a channel signal that is in a plurality of channel signals and whose initial reverb gain parameter needs to be adjusted. For example, the identifier field of the identification information occupies two bits. When the value of the identifier field is 00, this indicates that neither the initial reverb gain parameter of the first channel signal nor the initial reverb gain parameter of the second channel signal needs to be adjusted. When the value of the identifier field is 01, this Petition 870250082749, dated 09 / 15 / 2025, page 53 / 173 47 / 78 indicates that only the initial reverb gain parameter of the first channel signal needs to be adjusted. When the identifier field value is 10, this indicates that only the initial reverb gain parameter of the second channel signal needs to be adjusted. When the identifier field value is 11, this indicates that both the initial reverb gain parameter of the first channel signal and the second channel signal need to be adjusted.

[00173] In some embodiments, the determination of the indication information of the first channel signal and the second channel signal based on a correlation between the first channel signal and the downmixed signal, and a correlation between the second channel signal and the downmixed signal includes: determining the identification information of the first channel signal and the second channel signal based on the correlations between the energy of the first channel signal and the energy of the downmixed signal and between the energy of the second channel signal and the energy of the downmixed signal.

[00174] The correlation between the first channel signal and the downmixed signal and the correlation between the second channel signal and the downmixed signal can be conveniently measured using the energy of the channel signals and the energy of the downmixed signal, so that a channel signal whose initial reverb gain parameter needs to be adjusted can be conveniently determined.

[00175] In some embodiments, the energy or amplitude of the downmixed signal can be calculated based on the energy of the first channel signal and the energy of the second channel signal, thus simplifying the calculation process. Alternatively, the energy of the downmixed signal can be Petition 870250082749, dated 09 / 15 / 2025, page 54 / 173 48 / 78 calculated directly based on the downmixed signal itself.

[00176] 630. Quantize the first channel signal and the second channel signal based on the downmixed signal, the initial reverb gain parameter, and the identification information, and record a quantized first channel signal and a quantized second channel signal in a bitstream.

[00177] In this application, by determining a relationship between a predefined threshold and the size of a difference value between the energy of a channel signal and the energy of the downmixed signal, the channel signal can be defined as a channel signal whose initial reverb gain parameter needs to be adjusted when the energy of the channel signal is very different from the energy of the downmixed signal. Therefore, one side of the decoder can first adjust an initial reverb gain parameter of the channel signal and then perform reverb processing on the channel signal, thus improving the quality of a channel signal obtained after reverb processing.

[00178] Optionally, in one embodiment, the determination of the identification information of the first channel signal and the second channel signal based on the correlations between the energy of the first channel signal and the energy of the downmixed signal and between the energy of the second channel signal and the energy of the downmixed signal includes: determining a first difference value and a second difference value, wherein the first difference value is a sum of the absolute values ​​of the difference values ​​between the energy of the first channel signal and the energy of the downmixed signal in a plurality of frequency boxes, and the Petition 870250082749, dated 09 / 15 / 2025, page 55 / 173 49 / 78 second difference value is a sum of the absolute values ​​of the difference values ​​between the energy of the second channel signal and the energy of the downmixed signal in the frequency plurality; and determine the identification information of the first channel signal and the second channel signal based on the first difference value and the second difference value.

[00179] The difference between the energy of the first channel signal and the energy of the downmixed signal, and the difference between the energy of the second channel signal and the energy of the downmixed signal, can be conveniently determined by comparing the difference values ​​between the energy of the first channel signal and the energy of the downmixed signal in the frequency plurality and the energy of the second channel signal and the energy of the downmixed signal in the frequency plurality, in order to determine a channel signal whose initial reverb gain parameter needs to be adjusted. Therefore, it is unnecessary to compare the differences between the energy of the first channel signal and the energy of the downmixed signal and the differences between the energy of the second channel signal and the energy of the downmixed signal in all frequency bands.

[00180] Optionally, determining the identification information for the first channel signal and the second channel signal based on the first difference value and the second difference value includes: determining the larger difference value in the first difference value and the second difference value as a target difference value; and determining the identification information based on the target difference value, where the identification information indicates a signal Petition 870250082749, dated 09 / 15 / 2025, page 56 / 173 The 50 / 78 channel corresponding to the target difference value and the channel signal corresponding to the target difference value is a channel signal whose initial reverb gain parameter needs to be adjusted.

[00181] Specifically, when the sum of the absolute values ​​of the difference values ​​between the energy of the first channel signal and the energy of the downmixed signal in the frequency plurality is greater than the sum of the absolute values ​​of the difference values ​​between the energy of the second channel signal and the energy of the downmixed signal in the frequency plurality, the first channel signal can be determined as a channel signal whose initial reverb gain parameter needs to be adjusted.

[00182] Furthermore, when the sum of the absolute values ​​of the difference values ​​between the energy of the first channel signal and the energy of the downmixed signal in the frequency plurality, and the sum of the absolute values ​​of the difference values ​​between the energy of the second channel signal and the energy of the downmixed signal in the frequency plurality are relatively large (for example, both are greater than the preset limit), other identifying information can be determined, and the identifying information indicates that the initial reverb gain parameter of the first channel signal and the second channel signal need to be adjusted.

[00183] Specifically, in some embodiments, the determination of the identification information of the first channel signal and the second channel signal based on the sum of the absolute values ​​of the difference values ​​between the Petition 870250082749, dated 09 / 15 / 2025, page 57 / 173 51 / 78 The energy of the first channel signal or the energy of the second channel signal and the energy of the downmixed signal in the frequency plurality includes: generating first identification information when the sum of the absolute values ​​of the difference values ​​between the energy of the first channel signal and the energy of the downmixed signal in the frequency plurality is greater than the preset limit, where the first identification information indicates that the initial reverb gain parameter of the first channel signal needs to be adjusted; and generating second identification information when the sum of the absolute values ​​of the difference values ​​between the energy of the second channel signal and the energy of the downmixed signal in the frequency plurality is greater than the preset limit, where the second identification information indicates that the initial reverb gain parameter of the second channel signal needs to be adjusted.

[00184] By determining a relationship between the predefined threshold and the size of a difference value between the energy of a channel signal and the energy of the downmixed signal, the channel signal can be determined as a channel signal whose initial reverb gain parameter needs to be adjusted when the energy of the channel signal is very different from the energy of the downmixed signal. Therefore, one side of the decoder can first adjust an initial reverb gain parameter of the channel signal and then perform reverb processing on the channel signal, thus improving the quality of a channel signal obtained after reverb processing.

[00185] It should be understood that the identification information of the first channel signal and the second signal Petition 870250082749, dated 09 / 15 / 2025, page 58 / 173 52 / 78 channel information can be in one part of the identification information or in two parts of the identification information. For example, when the initial reverb gain parameter of the first channel signal and the second channel signal need to be adjusted, the identification information of the first channel signal and the second channel signal can be one part of the identification information, and the identification information indicates that the initial reverb gain parameter of the first channel signal and the second channel signal need to be adjusted.Alternatively, the identification information for the first channel signal and the second channel signal consists of two pieces of identification information: first identification information and second identification information, respectively. The first identification information indicates that the initial reverb gain parameter of the first channel signal needs to be adjusted, and the second identification information indicates that the initial reverb gain parameter of the second channel signal needs to be adjusted. When a channel signal does not have corresponding identification information, this indicates that an initial reverb gain parameter of the channel signal does not need to be adjusted. That is, when the identification information includes only the first identification information, only the initial reverb gain parameter of the first channel signal and the second channel signal need to be adjusted.

[00186] Optionally, in some modes, when the initial reverb gain parameter of the first channel signal needs to be adjusted, the method in FIG. 6 Petition 870250082749, dated 09 / 15 / 2025, page 59 / 173 53 / 78 also includes: determining a target attenuation factor based on the first difference value and the second difference value, where the target attenuation factor is used to adjust an initial reverb gain parameter of a target channel signal; and quantizing the target attenuation factor and recording a quantized target attenuation factor in the bitstream.

[00187] The initial reverb gain parameter of the channel signal can be flexibly adjusted based on the correlation value between the channel signal and the downmixed signal using the attenuation factor.

[00188] It should be understood that the first difference value and the second difference value can be calculated by referring to Formula (1) and Formula (2) above.

[00189] When the target attenuation factor is being determined based on the first difference value and the second difference value, the target attenuation factor can be determined based on a ratio between the first difference value and the second difference value.

[00190] In some embodiments, the target attenuation factor includes a plurality of attenuation factors, each of the plurality of attenuation factors corresponding to at least one sub-band of the target channel signal, and any sub-band corresponding to only one attenuation factor. For example, the multichannel signal includes a plurality of sub-bands, and adjacent sub-bands may correspond to one attenuation factor.

[00191] When the target attenuation factor includes a plurality of attenuation factors, a reverberation gain parameter can be adjusted more flexibly. Petition 870250082749, dated 09 / 15 / 2025, pp. 60 / 173 54 / 78 based on the target attenuation factor.

[00192] In some other embodiments, the target channel signal includes a first frequency band and a second frequency band, an attenuation factor corresponding to a sub-band in the first frequency band is less than or equal to an attenuation factor corresponding to a sub-band in the second frequency band, and a frequency of the first frequency band is less than the frequency of the second frequency band.

[00193] The reverberation gain parameters corresponding to a high-frequency sub-band and a low-frequency sub-band can be adjusted to different degrees by setting attenuation factors of different sizes for the reverberation gain parameters corresponding to the high-frequency sub-band and the low-frequency sub-band, and a better processing effect can be obtained during the reverberation process.

[00194] For example, a frequency band in which the target channel signal is located includes a low-frequency portion and a high-frequency portion, and the target attenuation factor includes a plurality of attenuation factors. The low-frequency portion corresponds to at least one attenuation factor, the high-frequency portion corresponds to at least one attenuation factor, and the attenuation factor corresponding to the low-frequency portion is less than the attenuation factor corresponding to the high-frequency portion.

[00195] In some modes, the energy of the downmixed signal is determined based on the energy of the first channel signal and the energy of the second channel signal. Petition 870250082749, dated 09 / 15 / 2025, pp. 61 / 173 55 / 78

[00196] The energy of the downmixed signal can be calculated using the energy of the first channel signal and the energy of the second channel signal, and a calculation process can be simplified without using the downmixed signal itself.

[00197] The foregoing describes the encoding method in the embodiment of this application in detail with reference to FIG. 6. The following describes a decoding method in the embodiment of this application with reference to FIG. 7. It should be understood that the decoding method in FIG. 7 corresponds to the encoding method in FIG. 6. For the sake of brevity, repeated descriptions are correctly omitted below.

[00198] FIG. 7 is a schematic flowchart of a multichannel signal decoding method according to an embodiment of this application. The method in FIG. 7 can be implemented by a decoder-side device or a decoder. The method in FIG. 7 specifically includes the following steps:

[00199] 710. Get a bitstream.

[00200] 720. Determine a downmixed signal of a first channel signal and a second channel signal into a multichannel signal, an initial reverb gain parameter of the first channel signal and the second channel signal, and identification information of the first channel signal and the second channel signal based on the bitstream, where the identification information indicates a channel signal that is in the first channel signal and the second channel signal and whose initial reverb gain parameter needs to be adjusted.

[00201] 730. Determine, as a target channel signal, Petition 870250082749, dated 09 / 15 / 2025, pp. 62 / 173 56 / 78 based on the identification information, the channel signal that is in the first channel signal and the second channel signal and whose initial reverb gain parameter needs to be adjusted.

[00202] 740. Adjust the initial reverb gain parameter of the target channel signal.

[00203] In this application, the channel signal whose initial reverb gain parameter needs to be adjusted can be determined using the identification information, and the initial reverb gain parameter of the channel signal is adjusted before reverb processing is performed on the channel signal, thus improving the quality of a channel signal obtained after reverb processing.

[00204] Optionally, in one embodiment, the adjustment of an initial reverberation gain parameter of the target channel signal includes: determining a target attenuation factor and adjusting the initial reverberation gain parameter of the target channel signal based on the target attenuation factor, to obtain a target reverberation gain parameter of the target channel signal.

[00205] The initial reverb gain parameter of the channel signal can be flexibly adjusted based on the size of a correlation between the channel signal and the downmixed signal using the attenuation factor.

[00206] When determining the attenuation factor, the decoder side can set a preset attenuation factor as the target attenuation factor. Alternatively, the decoder side directly adjusts the initial reverb gain parameter of the signal. Petition 870250082749, dated 09 / 15 / 2025, pp. 63 / 173 57 / 78 target channel based on a predefined attenuation factor.

[00207] A process for determining the target attenuation factor can be simplified by pre-configuring the attenuation factor, thereby improving decoding efficiency.

[00208] In some embodiments, the decoder side can obtain the target attenuation factor from bit streams of a plurality of channel signals, that is, obtain the target attenuation factor by decoding the bit stream of the plurality of channel signals. In this case, one side of the encoder has determined the target attenuation factor and encodes the target attenuation factor to obtain and transmit the bit stream to the decoder side. In this way, the decoder side no longer needs to calculate the target attenuation factor, but directly decodes the bit stream to obtain the target attenuation factor.

[00209] When the bitstream includes the target attenuation factor, the target attenuation factor can be obtained directly from the bitstream, and the process of determining the target attenuation factor can also be simplified, thus improving decoding efficiency.

[00210] Optionally, in one embodiment, the determination of a target attenuation factor specifically includes: obtaining an inter-channel level difference between the first channel signal and the second channel signal of the bitstream; and determining the target attenuation factor based on the inter-channel level difference, or determining the target attenuation factor based on the inter-channel level difference and the downmixed signal.

[00211] The target attenuation factor can be Petition 870250082749, dated 09 / 15 / 2025, pp. 64 / 173 58 / 78 is determined in a more flexible and precise way based on the level difference between channels, the downmixed signal, and similar factors, so that an initial reverb gain parameter of a channel signal can be adjusted more precisely based on the attenuation factor.

[00212] Specifically, when the level difference between channels is relatively large, it can be considered that a difference between the first channel signal and the second channel signal is relatively large, and a correlation between the first channel signal and the second channel signal is relatively small. In this case, an attenuation factor with a relatively large value can be determined as the target attenuation factor.

[00213] Furthermore, when the target attenuation factor is being determined based on the downmixed signal, the target attenuation factor can be determined using the periodicity and harmonicity of the downmixed signal. For example, when the periodicity or harmonicity of the downmixed signal is good, the difference between the first channel signal and the second channel signal can be considered relatively small, and the correlation between the first channel signal and the second channel signal is relatively large. In this case, an attenuation factor with a relatively small value can be determined as the target attenuation factor.

[00214] Optionally, in one embodiment, the target attenuation factor includes a plurality of attenuation factors, each of the plurality of attenuation factors corresponding to at least one sub-band of the target channel signal, and any sub-band corresponding to only one attenuation factor. For example, each of the first channel signal Petition 870250082749, dated 09 / 15 / 2025, pp. 65 / 173 59 / 78 and the second channel signal includes a plurality of subbands, and a plurality of adjacent subbands may correspond to an attenuation factor.

[00215] When the target attenuation factor includes a plurality of attenuation factors, a reverberation gain parameter can be adjusted more flexibly based on the target attenuation factor.

[00216] In some other embodiments, the target channel signal includes a first frequency band and a second frequency band, an attenuation factor corresponding to a sub-band in the first frequency band is less than or equal to an attenuation factor corresponding to a sub-band in the second frequency band, and a frequency of the first frequency band is less than the frequency of the second frequency band.

[00217] The reverberation gain parameters corresponding to a high-frequency sub-band and a low-frequency sub-band can be adjusted to different degrees by setting attenuation factors of different sizes for the reverberation gain parameters corresponding to the high-frequency sub-band and the low-frequency sub-band, and a better processing effect can be obtained during the reverberation process.

[00218] For example, a frequency band in which the target channel signal is located includes a low-frequency portion and a high-frequency portion, and the target attenuation factor includes a plurality of attenuation factors. The low-frequency portion corresponds to at least one attenuation factor, the high-frequency portion corresponds to at least one attenuation factor, and the factor of Petition 870250082749, dated 09 / 15 / 2025, pp. 66 / 173 60 / 78 attenuation corresponding to the low-frequency portion is less than the attenuation factor corresponding to the high-frequency portion.

[00219] The foregoing describes the encoding method and the decoding method in the embodiments of this application in detail with reference to FIGS. 3 to 7. The following describes an encoder and a decoder in the embodiments of this application with reference to FIGS. 8 to 13. It should be understood that the encoder and decoder in FIGS. 8 to 13 can implement the steps performed by the encoder and decoder in the encoding method and the decoding method in the embodiments of this application. For the sake of brevity, repeated descriptions are rightly omitted below.

[00220] FIG. 8 is a schematic block diagram of an encoder according to an embodiment of this application. An 800 encoder in FIG. 8 includes: a processing unit 810, configured to determine a downmixed signal from a first channel signal and a second channel signal into a multichannel signal, an initial reverb gain parameter of the first channel signal and the second channel signal; wherein the processing unit 810 is further configured to determine a target reverb 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 reverb gain parameter; and an encoding unit 820, configured to Petition 870250082749, dated 09 / 15 / 2025, pp. 67 / 173 61 / 78 quantize the first channel signal and the second channel signal based on the downmixed signal and the target reverb gain parameter, and record a quantized first channel signal and a quantized second channel signal in a bitstream.

[00221] The 800 encoder can match the multichannel signal encoding method in FIG. 3, and the 800 encoder can perform the multichannel signal encoding method in FIG. 3.

[00222] In the present application, when a target reverb gain parameter of a channel signal is being determined, a correlation between the channel signal and the downmixed signal is considered. In this way, a better processing effect can be obtained when reverb processing is performed on the channel signal based on the target reverb gain parameter, thus improving the quality of a channel signal obtained after reverb processing.

[00223] Optionally, in one embodiment, the 810 processing unit is specifically configured to determine a target attenuation factor based on the correlation between the first channel signal and the downmixed signal and the correlation between the second channel signal and the downmixed signal; and to adjust the initial reverb gain parameter based on the target attenuation factor to obtain the target reverb gain parameter.

[00224] Optionally, in one embodiment, each of the first channel signal and the second channel signal includes a plurality of frequency boxes, and the 810 processing unit is specifically configured to: Petition 870250082749, dated 09 / 15 / 2025, pp. 68 / 173 62 / 78 determine the difference values ​​between the energy of the first channel signal and the energy of the downmixed signal in the frequency plurality and between the energy of the second channel signal and the energy of the downmixed signal in the frequency plurality, and determine the target attenuation factor based on the difference values.

[00225] Optionally, in one embodiment, the 810 processing unit is specifically configured to: determine a first difference value between the energy of the first channel signal and the energy of the downmixed signal, wherein the first difference value indicates a sum of the absolute values ​​of the difference values ​​between the energy of the first channel signal and the energy of the downmixed signal in the frequency box plurality; determine a second difference value between the energy of the second channel signal and the energy of the downmixed signal, wherein the second difference value indicates a sum of the absolute values ​​of the difference values ​​between the energy of the second channel signal and the energy of the downmixed signal in the frequency box plurality; and determine the target attenuation factor based on a ratio between the first difference value and the second difference value.

[00226] Optionally, in one embodiment, before determining the target attenuation factor based on the difference values, the 810 processing unit is further specifically configured to: determine that the difference values ​​are greater than a predefined threshold.

[00227] Optionally, in one embodiment, the energy of the downmixed signal is determined based on the energy of the first channel signal and the energy of the second channel signal. Petition 870250082749, dated 09 / 15 / 2025, pp. 69 / 173 63 / 78 channel.

[00228] Optionally, in one embodiment, the target attenuation factor includes a plurality of attenuation factors, each of the plurality of attenuation factors corresponding to at least one sub-band of the multichannel signal, and any sub-band corresponding to only one attenuation factor.

[00229] FIG. 9 is a schematic diagram of an encoder according to an embodiment of this application. An encoder 900 in FIG. 9 includes: a 910 processing unit, configured to determine a downmixed signal from a first channel signal and a second channel signal into a multichannel signal, an initial reverb gain parameter of the first channel signal and the second channel signal; wherein the 910 processing unit is further configured to determine identification information of the first channel signal and the second channel signal based on a correlation between the first channel signal and the downmixed signal, and a correlation between the second channel signal and the downmixed signal, wherein the identification information indicates a channel signal that is in the first channel signal and the second channel signal and whose initial reverb gain parameter needs to be adjusted;and a 920 encoding unit, configured to quantize the first channel signal and the second channel signal based on the downmixed signal, the initial reverb gain parameter, and the identification information, and to record a quantized first channel signal and a quantized second channel signal in a bitstream. Petition 870250082749, dated 09 / 15 / 2025, pp. 70 / 173 64 / 78

[00230] In this application, a channel signal whose initial reverb gain parameter needs to be adjusted can be determined based on the correlation between the channel signal and the downmixed signal, so that one side of the decoder can first adjust the initial reverb gain parameter of some channel signals and then perform reverb processing on those channel signals, thus improving the quality of a channel signal obtained after reverb processing.

[00231] It should be understood that the 900 encoder can correspond to the multichannel signal encoding method in FIG. 6, and the 900 encoder can perform the multichannel signal encoding method in FIG. 6.

[00232] Optionally, in one embodiment, the 910 processing unit is specifically configured to determine the identification information of the first channel signal and the second channel signal based on a correlation between the energy of the first channel signal and the energy of the downmixed signal and a correlation between the energy of the second channel signal and the energy of the downmixed signal.

[00233] Optionally, in one embodiment, the 910 processing unit is specifically configured to: determine a first difference value and a second difference value, wherein the first difference value is a sum of the absolute values ​​of the difference values ​​between the energy of the first channel signal and the energy of the downmixed signal in a plurality of frequency boxes, and the second difference value is a sum of the absolute values ​​of the difference values ​​between the energy of the second channel signal and the energy of the downmixed signal in the plurality of boxes. Petition 870250082749, dated 09 / 15 / 2025, pp. 71 / 173 65 / 78 frequency; and determine the identification information of the first channel signal and the second channel signal based on the first difference value and the second difference value.

[00234] Optionally, in one embodiment, the processing unit 910 is specifically configured to determine the larger difference value in the first difference value and in the second difference value as a target difference value, and to determine the identification information based on the target difference value, wherein the identification information indicates a channel signal corresponding to the target difference value and the channel signal corresponding to the target difference value is a channel signal whose initial reverb gain parameter needs to be adjusted.

[00235] Optionally, in one embodiment, the 910 processing unit is further configured specifically to: determine a target attenuation factor based on the first difference value and the second difference value, where the target attenuation factor is used to adjust an initial reverb gain parameter of a target channel signal; and quantize the target attenuation factor, and record a quantized target attenuation factor in the bitstream.

[00236] Optionally, in one embodiment, the target attenuation factor includes a plurality of attenuation factors, each of the plurality of attenuation factors corresponding to at least one sub-band of the target channel signal, and any sub-band corresponding to only one attenuation factor.

[00237] Optionally, in one embodiment, the energy of the downmixed signal is determined based on the energy of Petition 870250082749, dated 09 / 15 / 2025, pp. 72 / 173 66 / 78 first channel signal and in the energy of the second channel signal.

[00238] FIG. 10 is a schematic block diagram of a decoder according to an embodiment of this application. A 1000 decoder in FIG. 10 includes: a 1010 acquisition unit, configured to obtain a bitstream; and a 1020 processing unit, configured to determine a downmixed signal from a first channel signal and a second channel signal into a multichannel signal, an initial reverb gain parameter of the first channel signal and the second channel signal, and identification information of the first channel signal and the second channel signal based on the bitstream, wherein the identification information indicates a channel signal that is in the first channel signal and the second channel signal and whose initial reverb gain parameter needs to be adjusted; wherein the 1020 processing unit is further configured to determine, as a target channel signal based on the identification information, the channel signal that is in the first channel signal and the second channel signal and whose initial reverb gain parameter needs to be adjusted;and the 1020 processing unit is further configured to adjust the initial reverb gain parameter of the target channel signal.

[00239] In this application, the channel signal whose initial reverb gain parameter needs to be adjusted can be determined using the identification information, and the Petition 870250082749, dated 09 / 15 / 2025, pp. 73 / 173 The 67 / 78 initial reverb gain parameter of the channel signal is adjusted before reverb processing is performed on the channel signal, thus improving the quality of a channel signal obtained after reverb processing.

[00240] It should be understood that decoder 1000 can correspond to the multichannel signal decoding method in FIG. 7, and decoder 1000 can perform the multichannel signal decoding method in FIG. 7.

[00241] Optionally, in one embodiment, the 1020 processing unit is specifically configured to determine a target attenuation factor and adjust the initial reverberation gain parameter of the target channel signal based on the target attenuation factor, in order to obtain a target reverberation gain parameter of the target channel signal.

[00242] Optionally, in one embodiment, the 1020 processing unit is specifically configured to determine a predefined attenuation factor as the target attenuation factor.

[00243] Optionally, in one embodiment, the 1020 processing unit is specifically configured to obtain the target attenuation factor based on the bit stream.

[00244] Optionally, in one embodiment, the 1020 processing unit is specifically configured to obtain a level difference between channels between the first channel signal and the second channel signal of the bitstream, and determine the target attenuation factor based on the level difference between channels, or determine the target attenuation factor based on the level difference between channels and the downmixed signal. Petition 870250082749, dated 09 / 15 / 2025, pp. 74 / 173 68 / 78

[00245] Optionally, in one embodiment, the target attenuation factor includes a plurality of attenuation factors, each of the plurality of attenuation factors corresponding to at least one sub-band of the target channel signal, and any sub-band corresponding to only one attenuation factor.

[00246] FIG. 11 is a schematic block diagram of an encoder according to an embodiment of this application. An 1100 encoder in FIG. 11 includes: A memory 1110, configured to store a program; and a processor 1120, configured to execute the program, and when the program is executed, the processor 1120 is configured to determine a downmixed signal from a first channel signal and a second channel signal into a multichannel signal, an initial reverb gain parameter of the first channel signal and the second channel signal; determine a target reverb 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 reverb gain parameter; and quantize the first channel signal and the second channel signal based on the downmixed signal and the target reverb gain parameter, and record a quantized first channel signal and a quantized second channel signal in a bitstream.

[00247] The 1100 encoder can match the multichannel signal encoding method in FIG. 3, and the 1100 encoder can perform the encoding method of Petition 870250082749, dated 09 / 15 / 2025, pp. 75 / 173 69 / 78 multichannel signal in FIG. 3.

[00248] In the present application, when a target reverb gain parameter of a channel signal is being determined, a correlation between the channel signal and the downmixed signal is considered. In this way, a better processing effect can be obtained when the reverb processing is performed on the channel signal based on the target reverb gain parameter, thus improving the quality of a channel signal obtained after reverb processing.

[00249] Optionally, in one embodiment, the 1120 processor is specifically configured to determine a target attenuation factor based on the correlation between the first channel signal and the downmixed signal and the correlation between the second channel signal and the downmixed signal; and adjust the initial reverb gain parameter based on the target attenuation factor to obtain the target reverb gain parameter.

[00250] Optionally, in one embodiment, each of the first channel signal and the second channel signal includes a plurality of frequency boxes, and the 1120 processor is specifically configured to: determine difference values ​​between the energy of the first channel signal and the energy of the downmixed signal in the plurality of frequency boxes and between the energy of the second channel signal and the energy of the downmixed signal in the plurality of frequency boxes, and determine the target attenuation factor based on the difference values.

[00251] Optionally, in one embodiment, the 1120 processor is specifically configured to: Petition 870250082749, dated 09 / 15 / 2025, pp. 76 / 173 70 / 78 determine a first difference value between the energy of the first channel signal and the energy of the downmixed signal, wherein the first difference value indicates a sum of the absolute values ​​of the difference values ​​between the energy of the first channel signal and the energy of the downmixed signal in the frequency plurality; determine a second difference value between the energy of the second channel signal and the energy of the downmixed signal, wherein the second difference value indicates a sum of the absolute values ​​of the difference values ​​between the energy of the second channel signal and the energy of the downmixed signal in the frequency plurality; and determine the target attenuation factor based on a ratio between the first difference value and the second difference value.

[00252] Optionally, in one embodiment, before determining the target attenuation factor based on the difference values, the 1120 processor is further specifically configured to: determine that the difference values ​​are greater than a predefined threshold.

[00253] Optionally, in one embodiment, the energy of the downmixed signal is determined based on the energy of the first channel signal and the energy of the second channel signal.

[00254] Optionally, in one embodiment, the target attenuation factor includes a plurality of attenuation factors, each of the plurality of attenuation factors corresponding to at least one sub-band of the multichannel signal, and any sub-band corresponding to only one attenuation factor.

[00255] FIG. 12 is a schematic block diagram. Petition 870250082749, dated 09 / 15 / 2025, pp. 77 / 173 71 / 78 of an encoder according to an embodiment of this application. An encoder 1200 in FIG. 12 includes: a memory 1210, configured to store a program; and a processor 1220, configured to execute the program, and when the program is executed, the processor 1220 is configured to determine a downmixed signal from a first channel signal and a second channel signal into a multichannel signal, an initial reverb gain parameter of the first channel signal and the second channel signal; determine identification information of the first channel signal and the second channel signal based on a correlation between the first channel signal and the downmixed signal, and a correlation between the second channel signal and the downmixed signal, wherein the identification information indicates a channel signal that is in the first channel signal and the second channel signal and whose initial reverb gain parameter needs to be adjusted;and quantize the first channel signal and the second channel signal based on the downmixed signal, the initial reverb gain parameter, and the identification information, and record a quantized first channel signal and a quantized second channel signal in a bitstream.

[00256] In this application, a channel signal whose initial reverb gain parameter needs to be adjusted can be determined based on the correlation between the channel signal and the downmixed signal, so that one side of the decoder can first adjust the initial reverb gain parameter of some channel signals and then perform reverb processing on those signals. Petition 870250082749, dated 09 / 15 / 2025, pp. 78 / 173 72 / 78 channel, thus improving the quality of a channel signal obtained after reverb processing.

[00257] It should be understood that the 1200 encoder can correspond to the multichannel signal encoding method in FIG. 6, and the 1200 encoder can perform the multichannel signal encoding method in FIG. 6.

[00258] Optionally, in one embodiment, the 1220 processor is specifically configured to determine the identification information of the first channel signal and the second channel signal based on a correlation between the energy of the first channel signal and the energy of the downmixed signal and a correlation between the energy of the second channel signal and the energy of the downmixed signal.

[00259] Optionally, in one embodiment, the 1220 processor is specifically configured to: determine a first difference value and a second difference value, wherein the first difference value is a sum of the absolute values ​​of the difference values ​​between the energy of the first channel signal and the energy of the downmixed signal in a plurality of frequency boxes, and the second difference value is a sum of the absolute values ​​of the difference values ​​between the energy of the second channel signal and the energy of the downmixed signal in the plurality of frequency boxes; and determine the identification information of the first channel signal and the second channel signal based on the first difference value and the second difference value.

[00260] Optionally, in one embodiment, the 1220 processor is specifically configured to determine the largest difference value in the first value of Petition 870250082749, dated 09 / 15 / 2025, pp. 79 / 173 73 / 78 difference and the second difference value as a target difference value, and determine the identification information based on the target difference value, wherein the identification information indicates a channel signal corresponding to the target difference value and the channel signal corresponding to the target difference value is a channel signal whose initial reverb gain parameter needs to be adjusted.

[00261] Optionally, in one embodiment, the 1220 processor is further configured specifically to: determine a target attenuation factor based on the first difference value and the second difference value, wherein the target attenuation factor is used to adjust an initial reverb gain parameter of a target signal channel; and quantize the target attenuation factor, and record a quantized target attenuation factor in the bitstream.

[00262] Optionally, in one embodiment, the target attenuation factor includes a plurality of attenuation factors, each of the plurality of attenuation factors corresponding to at least one sub-band of the target channel signal, and any sub-band corresponding to only one attenuation factor.

[00263] Optionally, in one embodiment, the energy of the downmixed signal is determined based on the energy of the first channel signal and the energy of the second channel signal.

[00264] FIG. 13 is a schematic block diagram of a decoder according to an embodiment of this application. A 1300 decoder in FIG. 13 includes: a 1310 memory, configured to store a program; and Petition 870250082749, dated 09 / 15 / 2025, pp. 80 / 173 74 / 78 a 1320 processor, configured to execute the program, and when the program is executed, the 1320 processor is configured to obtain a bitstream; determine a downmixed signal of a first channel signal and a second channel signal into a multichannel signal, an initial reverb gain parameter of the first channel signal and the second channel signal, and identification information of the first channel signal and the second channel signal based on the bitstream, where the identification information indicates a channel signal that is in the first channel signal and the second channel signal and whose initial reverb gain parameter needs to be adjusted; determine, as a target channel signal based on the identification information, the channel signal that is in the first channel signal and the second channel signal and whose initial reverb gain parameter needs to be adjusted;and adjust the initial reverb gain parameter of the target channel signal.

[00265] In this application, the channel signal whose initial reverb gain parameter needs to be adjusted can be determined using the identification information, and the initial reverb gain parameter of the channel signal is adjusted before reverb processing is performed on the channel signal, thus improving the quality of a channel signal obtained after reverb processing.

[00266] It should be understood that the 1300 decoder can correspond to the multichannel signal decoding method in FIG. 7, and the 1300 decoder can perform the multichannel signal decoding method in FIG. 7. Petition 870250082749, dated 09 / 15 / 2025, page 81 / 173 75 / 78

[00267] Optionally, in one embodiment, the 1320 processor is specifically configured to determine a target attenuation factor and adjust the initial reverberation gain parameter of the target channel signal based on the target attenuation factor, to obtain a target reverberation gain parameter of the target channel signal.

[00268] Optionally, in one embodiment, the 1320 processor is specifically configured to determine a predefined attenuation factor as the target attenuation factor.

[00269] Optionally, in one embodiment, the 1320 processor is specifically configured to obtain the target attenuation factor based on the bit stream.

[00270] Optionally, in one embodiment, the 1320 processor is specifically configured to obtain a level difference between channels between the first channel signal and the second channel signal of the bitstream, and determine the target attenuation factor based on the level difference between channels, or determine the target attenuation factor based on the level difference between channels and the downmixed signal.

[00271] Optionally, in one embodiment, the target attenuation factor includes a plurality of attenuation factors, each of the plurality of attenuation factors corresponding to at least one sub-band of the target channel signal and any sub-band corresponding to only one attenuation factor.

[00272] A person skilled in the art may be aware that, in combination with the examples of units and algorithm steps described in the embodiments disclosed in this Petition 870250082749, dated 09 / 15 / 2025, page 82 / 173 76 / 78 Descriptive Report The modalities may be implemented by electronic hardware or a combination of computer software and electronic hardware. Whether the functions are performed by hardware or software depends on specific applications and design constraints of the technical solutions. A person skilled in the art may use different methods to implement the functions described for each particular application, but it should not be considered that the implementation goes beyond the scope of this application.

[00273] It may be clearly understood by a person skilled in the art that, for the sake of convenient and brief description, for a detailed working process of the previous system, apparatus and unit, reference may be made to a corresponding process in the previous method embodiments, and details are not described here again.

[00274] In the various embodiments provided in this application, it should be understood that the disclosed system, apparatus, and method may be implemented in other ways. For example, the described apparatus embodiment is only one example. For instance, the unit division is merely a division of the logical function and may be another division in the actual implementation. For example, a plurality of units or components may be combined or integrated into another system, or some features may be omitted or not implemented. Furthermore, the mutual couplings shown or discussed, direct couplings, or communication links may be implemented using some interfaces. Indirect couplings or communication links between the apparatuses or units may be implemented in electronic, mechanical, or other forms. Petition 870250082749, dated 09 / 15 / 2025, page 83 / 173 77 / 78

[00275] The units described as separate parts may or may not be physically separate, and the parts displayed as units may or may not be physical units, may be located in one position, or may be distributed across a plurality of network units. Some or all of the units may be selected based on actual requirements to achieve the objectives of the embodiments' solutions.

[00276] In addition, the functional units in the embodiments of this request may be integrated into a processing unit, or each of the units may exist physically on its own, or two or more units may be integrated into a unit.

[00277] When functions are implemented in the form of a functional software unit and sold or used as a stand-alone product, the functions may be stored on a computer-readable storage medium. Based on such understanding, the technical solutions of this application essentially, or the part contributing to the state of the art, or some of the technical solutions may be implemented in the form of a software product. The software product is stored on a storage medium and includes various instructions to instruct a computer device (which may be a personal computer, a server, a network device, or similar) to perform all or some of the steps of the methods described in the embodiments of this application. The foregoing storage medium includes: any medium that stores program code, such as a USB drive, a removable hard disk, read-only memory, Petition 870250082749, dated 09 / 15 / 2025, page 84 / 173 78 / 78 ROM), a random access memory (RAM), a magnetic disk, or an optical disk.

[00278] The preceding descriptions are merely specific implementations of this application, but are not intended to limit the scope of protection of this application. Any variation or substitution readily determined by a person skilled in the art within the technical scope disclosed in this application shall be within the scope of protection of this application. Therefore, the scope of protection of this application shall be subject to the scope of protection of the claims. Petition 870250082749, dated 09 / 15 / 2025, page 85 / 173

Claims

1 / 2 CLAIMS 1. A multichannel signal encoding method, characterized in that it comprises: obtaining a multichannel signal, wherein the multichannel signal comprises a first channel signal and a second channel signal; performing downmixing processing on the first channel signal and the second channel signal to obtain a downmixed signal; obtaining an initial reverb gain parameter of the first channel signal and the second channel signal; determining the identification information of the first channel signal and the second channel signal based on a correlation between the first channel signal and the downmixed signal, and a correlation between the second channel signal and the downmixed signal, wherein the identification information is used to indicate a channel signal that is in the first channel signal and the second channel signal and whose initial reverb gain parameter needs to be adjusted;and quantize the first channel signal and the second channel signal based on the downmixed signal, the initial reverb gain parameter, and the identification information, and record a quantized first channel signal and a quantized second channel signal in a bitstream.

2. Method, according to claim 1, characterized in that the determination of the identification information of the first channel signal and the second channel signal based on a correlation between the first channel signal and the downmixed signal, and a correlation between Petition 870250082749, dated 09 / 15 / 2025, page 86 / 173 2 / 2 the second channel signal and the downmixed signal comprises: determining the identification information of the first channel signal and the second channel signal based on a correlation between the energy of the first channel signal and the energy of the downmixed signal and a correlation between the energy of the second channel signal and the energy of the downmixed signal.

3. Encoder, characterized in that it comprises: a memory and a processor, wherein the memory is configured to store instructions, the processor is configured to execute the instructions, and when the instructions are executed the processor performs the method as defined in either claim 1 or 2.

4. A computer-readable medium, characterized in that it stores instructions to be executed by a device, and the instructions are used to perform the method as defined in either claim 1 or 2. Petition 870250082749, dated 09 / 15 / 2025, pp. 87 / 173

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