Multichannel signal coding method and encoder

Description

1 / 77 MULTICHANNEL SIGNAL CODING METHOD AND ENCODER Divided from BR 112019021361-9

[001] This application claims priority over Chinese Patent Application No. 201710236773.3, filed with the Chinese Patent Office on April 12, 2017, and entitled MULTICHANNEL SIGNAL CODING METHOD, SIGNAL DECODING METHOD, ENCODER AND DECODER, 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) coding, intensity stereo (IS) coding, and parametric stereo (PS) coding.

[005] In the state of the art, when PS encoding is used to encode a multichannel signal, the encoder side needs to calculate a reverb gain parameter corresponding to each sub-band of a channel signal, and encode the reverb gain parameter corresponding to each sub-band of the channel signal, so that the decoder side can perform reverb processing on each sub-band of the channel signal based on the reverb gain parameter corresponding to each sub-band of the channel signal. However, a quantity Petition 870250032735, dated 04 / 24 / 2025, page 10 / 120 A relatively large 2 / 77 bit count needs to be occupied to encode the reverb gain parameter corresponding to each subband of the channel signal, and in some cases, performing reverb processing on each subband of the channel signal results in a worse auditory effect. SUMMARY

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

[007] According to a first aspect, a multichannel signal encoding method is provided, wherein the method includes: determining a reduced signal from a first channel signal and a second channel signal into a multichannel signal, and reverberation gain parameters corresponding to different sub-bands of the first channel signal and the second channel signal; determining a target reverberation gain parameter that needs to be encoded into the reverberation gain parameters corresponding to the different sub-bands of the first channel signal and the second channel signal; generating parameter indication information, wherein the parameter indication information is used to indicate a sub-band corresponding to the target reverberation gain parameter; and encoding the target reverberation gain parameter, the parameter indication information, and the reduced signal to generate a bitstream.

[008] In this application, when the first channel signal and the second channel signal are being encoded, the reverb gain parameters corresponding to only some sub-bands of the first channel signal and the second channel signal can be encoded. Compared to a prior art method, in which the reverb gain parameters corresponding to all sub-bands of the first channel signal and the second channel signal need to be encoded, the Petition 870250032735, dated 04 / 24 / 2025, page 11 / 120 3 / 77 bit overheads can be reduced to some extent and encoding efficiency can be improved. Specifically, a number of saved bits can be used to encode another parameter or allocate more bits to the reduced signal if the reverb gain parameters corresponding to some sub-bands are encoded, thus improving the overall encoding performance.

[009] With reference to the first aspect, in some implementations of the first aspect, the determination of a target reverberation gain parameter that needs to be encoded in the reverberation gain parameters corresponding to the different sub-bands of the first channel signal and the second channel signal includes: determining the target reverberation gain parameter based on at least one of: first channel signal energy and second channel signal energy, an inter-channel IC coherence between the first channel signal and the second channel signal, reduced signal energy, and an inter-channel ILD level difference between the first channel signal and the second channel signal.

[0010] The coherence between the first channel signal and the second channel signal can be determined based on the energy of the channel signal or the reduced signal energy, the IC, ILD, and similar, and target reverb gain parameters that need to be encoded can be adequately determined from reverb gain parameters corresponding to all sub-bands of the first channel signal and the second channel signal based on the coherence between the first channel signal and the second channel signal. Therefore, bits can be saved to some extent, considering the quality of the channel signal, and the coding efficiency can be improved. Specifically, when the coherence between the first channel signal and the second channel signal is relatively low, only the reverb gain parameters corresponding to the sub-bands of a low portion are needed. Petition 870250032735, dated 04 / 24 / 2025, page 12 / 120 4 / 77 The frequency of the first channel signal and the second channel signal can be encoded. When the coherence between the first channel signal and the second channel signal is relatively high, in addition to the reverberation gain parameters corresponding to the low-frequency sub-bands of the first channel signal and the second channel signal, the reverberation gain parameters corresponding to high-frequency sub-bands of the first channel signal and the second channel signal can also be encoded.

[0011] With reference to the first aspect, in some implementations of the first aspect, the determination of a target reverberation gain parameter that needs to be encoded in the reverberation gain parameters corresponding to the different sub-bands of the first channel signal and the second channel signal includes: determining the target reverberation gain parameter based on at least one coherence between the energy of the first channel signal and the energy of the reduced signal and coherence between the energy of the second channel signal and the energy of the reduced signal.

[0012] The values ​​for the energy of the first channel signal, the energy of the second channel signal, and the energy of the reduced signal can be obtained after normalization processing.

[0013] The coherence between the first channel signal and the second channel signal and the reduced signal can be conveniently measured using the energy of the channel signals, i.e., the target reverb gain parameter that needs to be encoded can be conveniently determined by comparing differences between the energy of the channel signals and the energy of the reduced signal. Specifically, when a difference between the energy of a channel signal and the energy of the reduced signal is relatively large, the coherence between the channel signal and the reduced signal can be considered relatively low, and in that case, only the reverb gain parameters corresponding to sub-bands Petition 870250032735, dated 04 / 24 / 2025, page 13 / 120 5 / 77 of a low-frequency portion of the channel signal can be encoded.

[0014] 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 the target reverberation gain parameter based on at least one coherence between the energy of the first channel signal and the energy of the reduced signal and coherence between the energy of the second channel signal and the energy of the reduced signal includes: determining a first difference value between the energy of the first channel signal and the energy of the reduced signal, where the first difference value is used to indicate a sum of the absolute values ​​of the difference values ​​between the energy of the first channel signal and the energy of the reduced signal in the plurality of frequency boxes;and when the first difference value is greater than a first limit, determine that a reverberation gain parameter corresponding to a sub-band of a first frequency band is the target reverberation gain parameter, where the first frequency band is part of all frequency bands of each of the first channel signal and the second channel 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 the target reverberation gain parameter based on at least one coherence between the energy of the first channel signal and the energy of the reduced signal and coherence between the energy of the second channel signal and the energy of the reduced signal includes: determining a second difference value between the energy of the second channel signal and the energy of the reduced signal, where the second difference value is used to indicate a sum of the absolute values ​​of the values ​​of Petition 870250032735, dated 04 / 24 / 2025, page 14 / 120 6 / 77 difference between the energy of the second channel signal and the energy of the reduced signal in the frequency box plurality; and when the second difference value is greater than a second threshold, determine that a reverberation gain parameter corresponding to a sub-band of a first frequency band is the target reverberation gain parameter, wherein the first frequency band is part of all frequency bands of each of the first channel signal and the second channel signal.

[0016] 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 the target reverberation gain parameter based on at least one coherence between the energy of the first channel signal and the energy of the reduced signal and coherence between the energy of the second channel signal and the energy of the reduced signal includes: determining a first difference value between the energy of the first channel signal and the energy of the reduced signal, where the first difference value is used to indicate a sum of the absolute values ​​of the difference values ​​between the energy of the first channel signal and the energy of the reduced signal in the plurality of frequency boxes;determine a second difference value between the energy of the second channel signal and the energy of the reduced signal, wherein the second difference value is used to indicate a sum of the absolute values ​​of the difference values ​​between the energy of the second channel signal and the energy of the reduced signal in the plurality of frequency boxes; and when the first difference value is greater than a first limit and the second difference value is greater than a second limit, determine that a reverberation gain parameter corresponding to a subband of a first frequency band is the target reverberation gain parameter, where the first frequency band is a; Petition 870250032735, dated 04 / 24 / 2025, page 15 / 120 7 / 77 part of all frequency bands of each of the first channel signal and the second channel signal.

[0017] The difference values ​​between the energy of the first channel signal and the energy of the reduced signal in the frequency box plurality, and the difference values ​​between the energy of the second channel signal and the energy of the reduced signal in the frequency box plurality, can be obtained after normalization processing.

[0018] It should be understood that when the coherence between the first channel signal or the second channel signal and the reduced signal is relatively high, the first channel signal and the second channel signal can be considered to be two channel signals that are relatively similar to each other (when the signals of the two channels are relatively similar, a mixed signal obtained by mixing the signals of the two channels is relatively similar to the signals of the two channels before mixing). When the coherence between the first channel signal or the second channel signal and the reduced signal is relatively low, the first channel signal and the second channel signal can be considered to be two channel signals that are relatively different from each other.

[0019] The coherence between the first channel signal and the reduced signal is used as an example. The coherence between the first channel signal and the reduced signal can be measured using the first difference value between the energy of the first channel signal and the energy of the reduced signal. When the first difference value is relatively large, the coherence between the first channel signal and the reduced signal can be considered relatively low. When the first difference value is relatively small, the coherence between the first channel signal and the reduced signal can be considered relatively high.

[0020] The differences between the energy of the first channel signal and the energy of the second channel signal and the energy of the signal Petition 870250032735, dated 04 / 24 / 2025, page 16 / 120 The reduced 8 / 77 gain can be conveniently determined by comparing the difference values ​​between the energy of the first channel signal and the energy of the second channel signal and the energy of the reduced signal in the plurality of frequency boxes, to further determine the target reverb gain parameter. Therefore, it is not necessary to compare the energy of the first channel signal and the energy of the second channel signal in all frequency bands.

[0021] When the energy of the first channel signal and / or the energy of the second channel signal is / are relatively different from the energy of the reduced signal, encoding reverberation gain parameters corresponding to sub-bands of some frequency bands of the first channel signal and the second channel signal can not only save bits to some extent, but also improve encoding performance. However, in the state of the art, reverberation gain parameters corresponding to sub-bands of all frequency bands of the first channel signal and the second channel signal are encoded.In this case, because the difference between the first channel signal and the second channel signal is relatively large, if the reverb gain parameters corresponding to the sub-bands of all frequency bands are still encoded and the reverb processing is performed based on the reverb gain parameters of all frequency bands, then finally the restored first channel signal and the second channel signal exhibit a relatively large distortion compared to the original signals.

[0022] With reference to the first aspect, in some implementations of the first aspect, a frequency in the first frequency band is lower than the frequency in another frequency band different from the first frequency band in the first channel signal and in the second channel signal.

[0023] It should be understood that the first frequency band Petition 870250032735, dated 04 / 24 / 2025, page 17 / 120 9 / 77 could be a low-frequency band.

[0024] When the difference between the first channel signal and the second channel signal is relatively large, a difference between the two channel signals is generally relatively large in a high-frequency part, but the difference between the two channel signals is relatively small in a low-frequency part. However, a channel signal in the low-frequency part affects the human auditory experience more. Therefore, when the difference between the first channel signal and the second channel signal is relatively large, only the reverberation gain parameters corresponding to the sub-bands of the low-frequency part can be encoded. In this way, not only can a bit be encoded, but also the auditory experience can be guaranteed.

[0025] With reference to the first aspect, in some implementations of the first aspect, the method also includes: When the first difference value is less than or equal to a first limit and the second difference value is less than or equal to a second limit, determine the reverb gain parameters corresponding to all sub-bands of the first channel signal and the second channel signal as the target reverb gain parameters. With reference to the first aspect, in some implementations of the first aspect, when the first difference value is less than or equal to the first limit or the second difference value is less than or equal to the second limit, the reverb gain parameters corresponding to all sub-bands of the first channel signal and the second channel signal are determined as target reverb gain parameters.

[0026] When the differences between the energy of the first channel signal and the energy of the second channel signal and the energy of the reduced signal are relatively large, only the reverb gain parameters corresponding to some sub-bands Petition 870250032735, dated 04 / 24 / 2025, page 18 / 120 10 / 77 can be encoded to reduce bit overhead during encoding and to avoid signal distortion caused during reverb processing as much as possible.

[0027] However, when the differences between the energy of the first channel signal and the energy of the second channel signal and the energy of the reduced signal are relatively small, the signal distortion caused by reverb processing in the channel signal is very small. To obtain a better listening effect, the reverb gain parameters corresponding to all sub-bands can be encoded.

[0028] With reference to the first aspect, in some implementations of the first aspect, the frequency box plurality is in a second frequency band of each of the first channel signal and second channel signal, and a frequency of the second frequency band is higher than a frequency of another frequency band, different from the second frequency band, in the first channel signal and in the second channel signal.

[0029] The differences between the energy of the first channel signal and the energy of the second channel signal and the energy of the reduced signal can be conveniently determined by comparing the difference values ​​between the energy of the first channel signal and the energy of the second channel signal and the energy of the reduced signal in the frequency plurality of the high-frequency section.

[0030] With reference to the first aspect, in some implementations of the first aspect, the determination of a target reverb gain parameter that needs to be encoded in the reverb gain parameters corresponding to the different sub-bands of the first channel signal and the second channel signal includes: determining the energy of N sub-bands of the reduced signal; determining M sub-bands from the N sub-bands, where the energy of any sub-band Petition 870250032735, dated 04 / 24 / 2025, page 19 / 120 11 / 77 in the M sub-bands is greater than the energy of any sub-band in the NM sub-bands in the N sub-bands, except the M sub-bands, M and N are integers greater than 0, and M is less than N; and determine the target reverb gain parameter based on a magnitude ratio between the energy of the M sub-bands and the energy of the NM sub-bands.

[0031] It should be understood that, when the reduced signal is a broadband signal, the N sub-bands may be all the sub-bands of the reduced signal and, when the reduced signal is an ultra-wideband signal, the N sub-bands may be sub-bands of the reduced signal in a broadband portion.

[0032] The coherence between the first channel signal and the second channel signal can be determined based on the energy of different sub-bands of the reduced signal, and further the target reverb gain parameter that needs to be encoded is determined based on the coherence between the first channel signal and the second channel signal.

[0033] The reduced signal can be a broadband signal or an ultra-wideband signal. When the reduced signal is a broadband signal, the N sub-bands can be all the sub-bands of the reduced signal, and when the reduced signal is an ultra-wideband signal, the N sub-bands can be sub-bands of the reduced signal in a broadband portion.

[0034] Alternatively, the M sub-bands can be determined based on the amplitude of each sub-band of the reduced signal, i.e., the amplitude of any sub-band in the M sub-bands of the reduced signal is greater than the amplitude of any sub-band in the N-M sub-bands of the reduced signal. A value of M can be predefined.

[0035] With reference to the first aspect, in some implementations of the first aspect, the determination of the target reverberation gain parameter is based on a magnitude relationship between the energy of the M sub-bands of the reduced signal and Petition 870250032735, dated 04 / 24 / 2025, page 20 / 120 12 / 77 The energy of the NM sub-bands of the reduced signal includes: when an average value of the energy of the M sub-bands is greater than K times the average value of the energy of the NM sub-bands, determine that a reverberation gain parameter corresponding to a sub-band of a first frequency band of the first channel signal and the second channel signal is the target reverberation gain parameter, where K is a real number greater than 0.

[0036] With reference to the first aspect, in some implementations of the first aspect, the determination of the target reverberation gain parameter based on a magnitude relationship between the energy of the M sub-bands of the reduced signal and the energy of the NM sub-bands of the reduced signal includes: when a sum of the energy of the M sub-bands is greater than L times the sum of the energy of the NM sub-bands, determine that a reverberation gain parameter corresponding to a sub-band of a first frequency band of the first channel signal and the second channel signal is the target reverberation gain parameter, where L is a real number greater than 0.

[0037] It should be understood that K and L can have different values.

[0038] The energy of the M sub-bands of the reduced signal and the energy of the NM sub-bands of the reduced signal can be compared by comparing the average value of the energy of the M sub-bands with the average value of the energy of the NM sub-bands. To further reduce the complexity of the calculation, the sum of the energy of the M sub-bands and the sum of the energy of the NM sub-bands can be compared directly. In this way, a calculation process is simplified to a certain extent and efficiency is improved.

[0039] When the differences between the energy of M sub-bands with relatively high energy and another sub-band with relatively low energy are relatively large, the difference between the first channel signal and the second channel signal can be considered relatively large. In this case, the Petition 870250032735, dated 04 / 24 / 2025, page 21 / 120 13 / 77 Reverb gain parameters corresponding to sub-bands of some frequency bands in the first channel signal and the second channel signal can be determined as target reverb gain parameters that need to be encoded. Specifically, the first frequency band can be a frequency band located in a low-frequency portion of the first channel signal and the second channel signal.

[0040] With reference to the first aspect, in some implementations of the first aspect, the determination of a target reverb gain parameter that needs to be encoded in the reverb gain parameters corresponding to the different sub-bands of the first channel signal and the second channel signal includes: determining the energy of N sub-bands of the reduced signal; determining M sub-bands of the N sub-bands, wherein the energy of any sub-band in the M sub-bands is greater than the energy of any sub-band in the NM sub-bands in the N sub-bands, except the M sub-bands;and when an index value of a first sub-band in the M sub-bands is less than a predefined index value, determine that a reverberation gain parameter corresponding to a sub-band of a first frequency band is the target reverberation gain parameter, wherein a frequency of any frequency box in the first sub-band is greater than the frequency of any frequency box in another sub-band in the M sub-bands, except the first sub-band, and the first frequency band is a part of all frequency bands of each of the first channel signal and second channel signal.

[0041] When an index value of a maximum frequency sub-band in the M sub-bands with relatively high energy is less than the predefined index value, the energy distribution of the M sub-bands of the reduced signal can be considered uneven, i.e., the coherence between the first channel signal and the second channel signal is relatively Petition 870250032735, dated 04 / 24 / 2025, page 22 / 120 14 / 77 small. In this case, only the reverb gain parameters corresponding to the sub-bands of some frequency bands need to be encoded.

[0042] With reference to the first aspect, in some implementations of the first aspect, the determination of a target reverb gain parameter that needs to be encoded in the reverb gain parameters corresponding to the different sub-bands of the first channel signal and the second channel signal includes: determining the energy of N sub-bands of the reduced signal; determining J target sub-bands from the N sub-bands based on the energy of the N sub-bands, where the energy of any sub-band in the J target sub-bands is greater than the energy of another sub-band different from the J target sub-bands, N and J are integers greater than 0 and J is less than N; and determining reverb gain parameters corresponding to the J target sub-bands as target reverb gain parameters.

[0043] A predetermined number of sub-bands is selected directly from all sub-bands based on the energy of each sub-band of the reduced signal, and the reverb gain parameters corresponding to the predetermined number of sub-bands are determined as target reverb gain parameters, so that a reverb gain parameter that needs to be encoded can be selected more flexibly.

[0044] With reference to the first aspect, in some implementations of the first aspect, the reduced signal energy is determined based on the energy of the first channel signal and the energy of the second channel signal.

[0045] The reduced signal energy is estimated or deduced based on the energy of the first channel signal and the energy of the second channel signal, which can reduce a certain amount of calculation. Petition 870250032735, dated 04 / 24 / 2025, page 23 / 120 15 / 77

[0046] According to a second aspect, a multichannel signal decoding method is provided, wherein the method includes: receiving a bitstream; obtaining a reduced signal of a first channel signal and a second channel signal into a multichannel signal and parameter indication information based on the bitstream, wherein the parameter indication information is used to indicate a target reverberation gain parameter encoded in the reverberation gain parameters corresponding to different sub-bands of the first channel signal and the second channel signal; obtaining the target reverberation gain parameter from the bitstream according to the parameter indication information; and determining the first channel signal and the second channel signal based on the reduced signal and the target reverberation gain parameter.

[0047] In this application, the target reverb gain parameter encoded by an encoder can be determined using the parameter indication information, and then reverb processing is performed on a corresponding sub-band of the first channel signal and the second channel signal based on the target reverb gain parameter.

[0048] According to a third aspect, a multichannel signal encoding method is provided, wherein the method includes: determining a reduced signal from a first channel signal and a second channel signal into a multichannel signal and reverberation gain parameters corresponding to different sub-bands of the first channel signal and the second channel signal; determining, based on the energy of N sub-bands of the reduced signal, a target reverberation gain parameter that needs to be encoded into the reverberation gain parameters corresponding to the different sub-bands of the first channel signal and the second channel signal, wherein N is an integer greater than 0; and encoding the reduced signal and the target reverberation gain parameter. Petition 870250032735, dated 04 / 24 / 2025, page 24 / 120 16 / 77

[0049] In this application, a specific number of sub-bands are selected directly from all sub-bands based on the energy of each sub-band of the reduced signal, so that a reverb gain parameter that needs to be encoded can be selected more flexibly. Furthermore, compared to a way of determining the reverb gain parameter corresponding to a sub-band of a fixed frequency band as a target reverb gain parameter, the reverb gain parameters corresponding to some sub-bands that may not be adjacent in the frequency domain can be selected directly as target reverb gain parameters.

[0050] With reference to the third aspect, in some implementations of the third aspect, the determination, based on the energy of N sub-bands of the reduced signal, of a target reverberation gain parameter that needs to be encoded in the reverberation gain parameters corresponding to the different sub-bands of the first channel signal and the second channel signal includes: determining J target sub-bands from the N sub-bands based on the energy of the N sub-bands, where the energy of any sub-band in the J target sub-bands is greater than the energy of another sub-band different from the J target sub-bands, N and J are integers greater than 0 and J is less than N; and determining reverberation gain parameters corresponding to the J target sub-bands as target reverberation gain parameters.

[0051] In this application, a predetermined number of subbands is selected directly from all subbands based on the energy of each subband of the reduced signal, and the reverb gain parameters corresponding to the predetermined number of subbands are determined as target reverb gain parameters, so that a reverb gain parameter that needs to be encoded can be selected more flexibly. Petition 870250032735, dated 04 / 24 / 2025, page 25 / 120 17 / 77

[0052] According to a fourth aspect, a multichannel signal decoding method is provided, wherein the method includes: receiving a bitstream; determining a reduced signal of a first channel signal and a second channel signal into a multichannel signal based on the bitstream; determining, based on the energy of N sub-bands of the reduced signal, a target reverberation gain parameter encoded in the reverberation gain parameters corresponding to different sub-bands of the first channel signal and the second channel signal, wherein N is an integer greater than 0; determining the target reverberation gain parameter based on the bitstream; and determining the first channel signal and the second channel signal based on the reduced signal and the target reverberation gain parameter.

[0053] In this application, one side of the decoder can directly determine, based on the energy of a plurality of subbands of the reduced signal, the target reverberation gain parameter encoded in the reverberation gain parameters corresponding to the different subbands of the first channel signal and the second channel signal, so that the bits occupied by the decoder side to transmit indication information to indicate the encoded target reverberation gain parameter are reduced and the signaling overheads can be reduced to a certain extent.

[0054] With reference to the fourth aspect, in some implementations of the fourth aspect, the determination, based on the energy of N sub-bands of the reduced signal, of a target reverberation gain parameter encoded in reverberation gain parameters corresponding to different sub-bands of the first channel signal and the second channel signal includes: determining J target sub-bands from the N sub-bands based on the energy of the N sub-bands, wherein the energy of any sub-band in the J target sub-bands is greater than the energy of another sub-band different from the J target sub-bands, both N and J are integers greater than 0 and J is Petition 870250032735, dated 04 / 24 / 2025, p. 26 / 120 18 / 77 less than N; and determine reverb gain parameters corresponding to the target J sub-bands as target reverb gain parameters.

[0055] According to a fifth 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.

[0056] According to a sixth aspect, a decoder is provided, and the decoder includes a module or unit configured to execute the method in the second aspect or in various implementations of the second aspect.

[0057] According to a seventh aspect, an encoder is provided, and the encoder includes a module or unit configured to execute the method in the third aspect or in various implementations of the third aspect.

[0058] According to an eighth aspect, a decoder is provided, and the decoder includes a module or unit configured to execute the method in the fourth aspect or in various implementations of the fourth aspect.

[0059] According to a ninth aspect, an encoder is provided, including 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 first aspect or various implementations of the first aspect.

[0060] According to a tenth aspect, a decoder is provided, including 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 second aspect or various implementations of the second aspect.

[0061] According to an eleventh aspect, an encoder is provided, including memory and a processor, where the Petition 870250032735, dated 04 / 24 / 2025, p. 27 / 120 19 / 77 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 various implementations of the third aspect.

[0062] According to a twelfth aspect, a decoder is provided, including 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 fourth aspect or various implementations of the fourth aspect.

[0063] According to a thirteenth 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.

[0064] According to a fourteenth 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 various implementations of the second aspect.

[0065] According to a fifteenth 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.

[0066] According to a sixteenth 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 fourth aspect or various implementations of the first. Petition 870250032735, dated 04 / 24 / 2025, page 28 / 120 20 / 77 aspect. BRIEF DESCRIPTION OF THE DRAWINGS

[0067] Figure 1 is a schematic flowchart of encoding a left-channel signal and a right-channel signal in the state of the art; Figure 2 is a schematic flowchart for decoding a left-channel signal and a right-channel signal in the state of the art; Figure 3 is a schematic flowchart of a multichannel signal encoding method according to one embodiment of this application; Figure 4 is a schematic flowchart of a multichannel signal decoding method according to one embodiment of this application; Figure 5 is a schematic flowchart of a multichannel signal encoding method according to one embodiment of this application; Figure 6 is a schematic flowchart of a multichannel signal decoding method according to one embodiment of this application; Figure 7 is a schematic flowchart of a multichannel signal encoding method according to one embodiment of this application; Figure 8 is a schematic flowchart of a multichannel signal decoding method according to one embodiment of this application; Figure 9 is a schematic flowchart of a multichannel signal encoding method according to one embodiment of this application; Figure 10 is a schematic flowchart of a multichannel signal decoding method according to one embodiment of this application; Figure 11 is a schematic block diagram of a Petition 870250032735, dated 04 / 24 / 2025, page 29 / 120 21 / 77 encoder in accordance with a modality of this request; Figure 12 is a schematic block diagram of a decoder according to one embodiment of this application; Figure 13 is a schematic block diagram of an encoder according to one embodiment of this application; Figure 14 is a schematic block diagram of a decoder according to one embodiment of this application; Figure 15 is a schematic block diagram of an encoder according to one embodiment of this application; Figure 16 is a schematic block diagram of a decoder according to one embodiment of this application; Figure 17 is a schematic block diagram of an encoder according to an embodiment of this application; and Figure 18 is a schematic block diagram of a decoder according to an embodiment of this application. DESCRIPTION OF THE MODALITIES

[0068] 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 Figure 1 and Figure 2.

[0069] Figure 1 shows a state-of-the-art encoding process for a left-channel signal and a right-channel signal. The encoding process shown in Figure 1 specifically includes the following steps.

[0070] 110. Perform spatial parameter analysis and reduction processing on a left-channel signal (represented by L in the figure) and on a right-channel signal (represented by R in the figure).

[0071] Specifically, step 110 includes: performing spatial parameter analysis on the left channel signal. Petition 870250032735, dated 04 / 24 / 2025, page 30 / 120 22 / 77 and on the right channel signal to obtain a spatial parameter of the left channel signal and a spatial parameter of the right channel signal; and perform reduction processing on the left channel signal and on the right channel signal to obtain a reduced signal (where the reduced signal obtained after reduction processing is a mono audio signal, and the two original audio signal channels are converted into one audio signal channel through reduction processing).

[0072] The spatial parameter (also called the spatial detection parameter) includes inter-channel coherence (IC), inter-channel level difference (ILD), inter-channel time difference (ITD), inter-channel phase difference (IPD), and the like.

[0073] IC describes cross-channel coherence or coherence. This parameter determines the detection of a range of the sound field 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 describe an intensity difference between channels, and 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 and 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 IPD can represent a similarity in the waveform of the left-channel signal and the right-channel signal of the stereo system after time alignment.ILD, ITD, and IPD can determine the human ear's detection of a sound source location, effectively pinpointing the sound source's location and playing a role. Petition 870250032735, dated 04 / 24 / 2025, page 31 / 120 23 / 77 is important in restoring the stereo signal.

[0074] 120. Encode the reduced signal to obtain a bit stream.

[0075] 130. Encode the spatial parameters to obtain a bitstream.

[0076] 140. Multiplex the bit stream obtained by encoding the reduced signal and the bit stream obtained by encoding the spatial parameters to obtain a bit stream.

[0077] The bit stream obtained through encoding can be stored or transmitted to a device on the decoder side.

[0078] Figure 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 Figure 2 specifically includes the following steps.

[0079] 210. Demultiplex a bit stream to obtain separately a bit stream obtained by encoding a reduced signal and a bit stream obtained by encoding a spatial parameter.

[0080] The reduced signal and spatial parameter are obtained by decoding based on a demultiplexed bitstream.

[0081] In step 210, one side of the decoder can separately decode the reduced signal and the spatial parameter.

[0082] The spatial parameter is used to indicate an IC of the left channel signal and the right channel signal.

[0083] 220. Obtain a decoherence signal.

[0084] In addition, the left channel signal and the right channel signal are obtained based on a decoded reduced signal and the decoherence signal of a current frame.

[0085] 230. Finally, obtain the left-channel and right-channel output signals (representatively shown by L' and R' in Figure 2) based on the parameters Petition 870250032735, dated 04 / 24 / 2025, page 32 / 120 24 / 77 spatial, on the left channel signal and on 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 Figure 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 downslung signal can be filtered and then an inter-channel coherence parameter is used to correct a filtered downslung signal to obtain a decoherence signal.

[0088] One objective of generating the decoherence 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, such as reflecting and refracting an original audio signal differently and then superimposing the reflected and refracted audio signals onto the original audio signal to enter the human ear.

[0089] In the prior art, when a multichannel signal is encoded, the multichannel signal is generally divided into a plurality of sub-bands, a corresponding IC for each sub-band is determined, and the IC corresponding to each sub-band is subsequently encoded. However, encoding the IC corresponding to each sub-band definitely increases the number of bits occupied during encoding. In some cases, for example, when the coherence between a plurality of channel signals is relatively low, high-frequency parts of the plurality of channel signals are relatively different. In this case, if the ICs corresponding to the high-frequency parts Petition 870250032735, dated 04 / 24 / 2025, page 33 / 120 If the 25 / 77 frequency of the channel plurality signals are still encoded, and the decoder side performs reverb processing on the high-frequency parts of the channel plurality signals based on the ICs corresponding to the high-frequency parts of the channel plurality signals, a restored channel plurality signal is quite distorted.

[0090] Therefore, one embodiment of this application provides a multichannel signal encoding method, such that the reverb gain parameters of some sub-bands in a multichannel signal can be adaptably selected for encoding, to effectively use the bits. What follows describes in detail the multichannel signal encoding method in this embodiment of this application with reference to the attached drawings.

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

[0092] 310. Determine a reduced signal of a first channel signal and a second channel signal in a multichannel signal and reverb gain parameters corresponding to different sub-bands of the first channel signal and the second channel signal.

[0093] The multichannel signal can be a plurality of channel signals. Furthermore, prior to step 310, the method may include obtaining the first channel signal and the second channel signal within the multichannel signal.

[0094] This modality of this application does not define a limitation in a sequence between a process of determining the reduced signal and a process of determining the reverberation gain parameters corresponding to the different sub-bands of Petition 870250032735, dated 04 / 24 / 2025, page 34 / 120 26 / 77 first channel signal and second channel signal. The processes can be performed simultaneously or sequentially.

[0095] Specifically, the reduced signal can be obtained by performing reduction processing on the first channel signal and the second channel signal. The spatial parameters of the first channel signal and the second channel signal are obtained through spatial parameter analysis on the first channel signal and the second channel signal. The spatial parameters include the reverberation gain parameters corresponding to the different sub-bands of the first channel signal and the second channel signal, and other spatial parameters such as an IC, an ILD, an ITD, and an IPD.

[0096] It should be understood that the first channel signal and the second channel signal 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 an initial reverberation gain parameter of the first channel signal and an initial reverberation gain parameter of the second channel signal are the same.

[0097] Furthermore, assuming that each of the first channel signal and the second channel signal 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 are the same.

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

[0099] 320. Determine a target reverb gain parameter that needs to be encoded into the reverb gain parameters corresponding to the different sub-bands of Petition 870250032735, dated 04 / 24 / 2025, page 35 / 120 27 / 77 first channel signal and second channel signal.

[00100] 330. Generate parameter indication information, where parameter indication information is used to indicate a sub-band corresponding to the target reverb gain parameter.

[00101] The parameter indication information can indicate, using a flag bit, the sub-band corresponding to the target reverb gain parameter. For example, each of the first channel signal and the second channel signal includes 10 sub-bands (the sub-band index numbers are 0 to 9), the parameter indication information includes 10 flag bits, and the 10 flag bits successively correspond to the 10 sub-bands of each of the first channel signal and the second channel signal. When a flag bit corresponding to a sub-band is 1, a reverb gain parameter corresponding to the sub-band is a target reverb gain parameter that needs to be encoded. However, if a flag bit corresponding to a sub-band is 0, a reverb gain parameter corresponding to the sub-band will not be a target reverb gain parameter.In this way, when performing the encoding, one side of the encoder encodes only one reverb gain parameter corresponding to a sub-band whose flag bit is 1.

[00102] Alternatively, the parameter indication information needs to include only one flag bit, and the flag bit is either 1 or 0. When the flag bit is 1, it indicates that a reverb gain parameter of a selected target sub-band should be encoded. When the flag bit is 0, it indicates that the reverb gain parameters of all sub-bands should be encoded.

[00103] Specifically, the index numbers of all sub-bands of the first channel signal and the second channel signal are from 0 to 9, and the sub-bands whose index numbers are 0 Petition 870250032735, dated 04 / 24 / 2025, page 36 / 120 28 / 77 to 5 are target sub-bands. In this case, when the flag bit of the parameter indication information is 1, the reverb gain parameters of the sub-bands whose index numbers are 0 to 5 should be encoded. When the flag bit of the parameter indication information is 0, the reverb gain parameters of the sub-bands whose index numbers are 0 to 9 should be encoded.

[00104] 340. Encode the target reverb gain parameter, parameter indication information, and reduced signal to generate a bitstream.

[00105] In this application, when the first channel signal and the second channel signal are being encoded, the reverb gain parameters corresponding to only some sub-bands of the first channel signal and the second channel signal can be encoded. Compared with a prior art method, in which the reverb gain parameters corresponding to all sub-bands of the first channel signal and the second channel signal need to be encoded, bit overheads can be reduced to some extent and encoding efficiency can be improved.

[00106] Specifically, a quantity of saved bits can be used to encode another parameter or allocate more bits to the reduced signal if the reverb gain parameters corresponding to some sub-bands are encoded, thus improving the overall encoding performance.

[00107] For example, reverb gain parameters corresponding to sub-bands of a low-frequency portion of the first channel signal and the second channel signal can be selected as target reverb gain parameters that need to be encoded, and reverb gain parameters corresponding to sub-bands of a high-frequency portion of the first channel signal and the second channel signal should not be encoded. Petition 870250032735, dated 04 / 24 / 2025, page 37 / 120 29 / 77

[00108] Optionally, when the reverb gain parameters corresponding to the different sub-bands of the first channel signal and second channel signal are being generated, the reverb gain parameters corresponding to all sub-bands of the first channel signal and second channel signal can be generated, i.e., all reverb gain parameters of the first channel signal and second channel signal are generated and then only the target reverb gain parameter in all reverb gain parameters is encoded during encoding.

[00109] Alternatively, to further improve coding efficiency, when spatial parameter analysis is performed on the first channel signal and the second channel signal, only the target reverberation gain parameter needs to be generated, but a remaining reverberation gain parameter that is not coded is not generated. Specifically, if the target reverberation gain parameter corresponds to a target sub-band of the first channel signal and the second channel signal, when spatial parameter analysis is performed on the first channel signal and the second channel signal, only a reverberation gain parameter corresponding to the target sub-band of the first channel signal and the second channel signal needs to be determined, and a reverberation gain parameter corresponding to another sub-band of the first channel signal and the second channel signal does not need to be determined. In this way, coding efficiency can be further improved.

[00110] Optionally, in one embodiment, the determination of a target reverberation gain parameter that needs to be encoded in the reverberation gain parameters corresponding to the different sub-bands of the first channel signal and the second channel signal includes: determining the target reverberation gain parameter based on at least one of: Petition 870250032735, dated 04 / 24 / 2025, page 38 / 120 30 / 77 energy of the first channel signal and energy of the second channel signal, an IC between the first channel signal and the second channel signal, magnitude of the energy of different sub-bands of the reduced signal, and an ILD between the first channel signal and the second channel signal.

[00111] Specifically, the coherence between the first channel signal and the second channel signal can be determined based on the energy of the first channel signal and the energy of the second channel signal or the energy of the reduced signal, the inter-channel coherence between the first channel signal and the second channel signal, and the inter-channel level difference between the first channel signal and the second channel signal. Furthermore, the target reverb gain parameters that need to be encoded are appropriately determined based on the coherence between the first channel signal and the second channel signal of the reverb gain parameters corresponding to all sub-bands of the first channel signal and the second channel signal, so that bits can be saved to some extent and the coding efficiency can be improved.

[00112] For example, when the coherence between the first channel signal and the second channel signal is relatively low, only the reverberation gain parameters corresponding to the low-frequency sub-bands of the first and second channel signals can be encoded. When the coherence between the first and second channel signals is relatively high, in addition to the reverberation gain parameters corresponding to the low-frequency sub-bands of the first and second channel signals, the reverberation gain parameters corresponding to the high-frequency sub-bands of the first and second channel signals can also be encoded. That is, when the coherence between the first and second channel signals is relatively high, the parameters of Petition 870250032735, dated 04 / 24 / 2025, page 39 / 120 31 / 77 reverb gain corresponding to all sub-bands of the first channel signal and the second channel signal can be encoded.

[00113] When the target reverb gain parameter is determined based on the IC between the first channel signal and the second channel signal, a size of an IC value between the first channel signal and the second channel signal can be determined, and the coherence between the first channel signal and the second channel signal is determined based on the size of the IC value. For example, when the IC value between the first channel signal and the second channel signal is relatively small (in this case, the coherence between the first channel signal and the second channel signal can be considered relatively low), the reverb gain parameters corresponding to the low-frequency subbands of the first channel signal and the second channel signal can be determined as target reverb gain parameters.When the IC value between the first channel signal and the second channel signal is relatively large (in this case, the coherence between the first channel signal and the second channel signal can be considered relatively high), the reverberation gain parameters corresponding to the low-frequency sub-bands and the high-frequency sub-bands of the first channel signal and the second channel signal (or the sub-bands of all frequency bands of the first channel signal and the second channel signal) can be determined as target reverberation gain parameters.

[00114] Optionally, in one embodiment, the determination of a target reverberation gain parameter that needs to be encoded in the reverberation gain parameters corresponding to the different sub-bands of the first channel signal and the second channel signal includes: determining the target reverberation gain parameter based on at least one of Petition 870250032735, dated 04 / 24 / 2025, page 40 / 120 32 / 77 coherence between the energy of the first channel signal and the energy of the reduced signal and coherence between the energy of the second channel signal and the energy of the reduced signal.

[00115] That is, when the target reverberation gain parameter is being determined, the target reverberation gain parameter can be determined separately based on the coherence between the energy of the first channel signal and the energy of the reduced signal or the coherence between the energy of the second channel signal and the energy of the reduced signal, or the target reverberation gain parameter can be determined jointly based on the coherence between the energy of the first channel signal and the energy of the reduced signal and the coherence between the energy of the second channel signal and the energy of the reduced signal.

[00116] Specifically, in some embodiments, each of the first channel signal and the second channel signal includes a plurality of frequency boxes, and the determination of the target reverberation gain parameter based on at least one coherence between the energy of the first channel signal and the energy of the reduced signal and the coherence between the energy of the second channel signal and the energy of the reduced signal includes: determining a first difference value between the energy of the first channel signal and the energy of the reduced signal, wherein the first difference value is used to indicate a sum of the absolute values ​​of the difference values ​​between the energy of the first channel signal and the energy of the reduced signal in the plurality of frequency boxes;and when the first difference value is greater than a first limit, determine that a reverberation gain parameter corresponding to a subband of a first frequency band is the target reverberation gain parameter, where the first frequency band is part of all frequency bands of each of the first channel signal and the second channel signal.

[00117] In other modalities, each of the first sign of Petition 870250032735, dated 04 / 24 / 2025, p. 41 / 120 33 / 77 channel and the second channel signal includes a plurality of frequency boxes, and the determination of the target reverberation gain parameter based on at least one coherence between the energy of the first channel signal and the energy of the reduced signal and the coherence between the energy of the second channel signal and the energy of the reduced signal includes: determining a second difference value between the energy of the second channel signal and the energy of the reduced signal, where the second difference value is used to indicate a sum of absolute values ​​of difference values ​​between the energy of the second channel signal and the energy of the reduced signal in the plurality of frequency boxes;and when the second difference value is greater than a second threshold, determine that a reverberation gain parameter corresponding to a sub-band of a first frequency band is the target reverberation gain parameter, where the first frequency band is part of all frequency bands of each of the first channel signal and the second channel signal.

[00118] In other embodiments, each of the first channel signal and the second channel signal includes a plurality of frequency boxes, and the determination of the target reverberation gain parameter based on at least one coherence between the energy of the first channel signal and the energy of the reduced signal and the coherence between the energy of the second channel signal and the energy of the reduced signal includes: determining a first difference value between the energy of the first channel signal and the energy of the reduced signal, wherein the first difference value is used to indicate a sum of absolute values ​​of difference values ​​between the energy of the first channel signal and the energy of the reduced signal in the plurality of frequency boxes; determining a second difference value between the energy of the second channel signal and the energy of the reduced signal, wherein the second difference value is used to indicate a sum of Petition 870250032735, dated 04 / 24 / 2025, page 42 / 120 34 / 77 absolute values ​​of the difference values ​​between the energy of the second channel signal and the energy of the reduced signal in the frequency box plurality; and when the first difference value is greater than a first limit and the second difference value is greater than a second limit, determine that a reverberation gain parameter corresponding to a subband of a first frequency band is the target reverberation gain parameter, where the first frequency band is a part of all frequency bands of each of the first channel signal and the second channel signal.

[00119] The difference values ​​between the energy of the first channel signal and the energy of the reduced signal in the frequency box plurality, and the difference values ​​between the energy of the second channel signal and the energy of the reduced signal in the frequency box plurality, can be obtained after normalization processing.

[00120] The first limit and the second limit can be predefined. The first limit and the second limit can be the same or different.

[00121] The coherence between the first channel signal and the second channel signal and the reduced signal can be conveniently measured based on the energy of the channel signals, i.e., the target reverb gain parameter that needs to be encoded can be conveniently determined by comparing the differences between the energy of the channel signals and the energy of the reduced signal.

[00122] For example, when the difference between the energy of the first channel signal and the energy of the reduced signal is relatively large, the coherence between the first channel signal and the reduced signal can be considered to be relatively low, and in that case, only the reverberation gain parameters corresponding to the low-frequency sub-bands of the first channel signal can be encoded. Petition 870250032735, dated 04 / 24 / 2025, page 43 / 120 35 / 77

[00123] It should be understood that when the coherence between the first channel signal or the second channel signal and the reduced signal is relatively high, the first channel signal and the second channel signal can be considered to be two channel signals that are relatively similar to each other (when the two channel signals are relatively similar, a mixed signal obtained by mixing the two channel signals is relatively similar to the two channel signals before mixing). When the coherence between the first channel signal or the second channel signal and the reduced signal is relatively low, the first channel signal and the second channel signal can be considered to be two channel signals that are relatively different from each other.

[00124] The coherence between the first channel signal and the reduced signal is used as an example. The coherence between the first channel signal and the reduced signal can be measured using the first difference value between the energy of the first channel signal and the energy of the reduced signal. When the first difference value is relatively large, the coherence between the first channel signal and the reduced signal can be considered relatively low. When the first difference value is relatively small, the coherence between the first channel signal and the reduced signal can be considered relatively high.

[00125] When at least one of the first difference values ​​and the second difference values ​​exceeds the corresponding limit, the coherence between the first channel signal and the second channel signal can be considered relatively low. In this case, the reverb gain parameters corresponding to sub-bands of some frequency bands of the first channel signal and the second channel signal are encoded, which can not only save bits to some extent but also improve encoding performance. However, in this case, in the state of the art, the corresponding reverb gain parameters Petition 870250032735, dated 04 / 24 / 2025, page 44 / 120 36 / 77 to the sub-bands of all frequency bands of the first channel signal and the second channel signal are still encoded. In this case, because the difference between the first channel signal and the second channel signal is relatively large, if the reverb gain parameters corresponding to the sub-bands of all frequency bands are still encoded, and the reverb processing is performed based on the reverb gain parameters of all frequency bands, finally the restored first channel signal and the second channel signal exhibit a relatively large distortion compared to the original signals.

[00126] Certainly, alternatively, only when the first difference value and the second difference value are greater than the corresponding limits, the reverberation gain parameter corresponding to the sub-band of the first frequency band of the first channel signal and the second channel signal can be determined as the target reverberation gain parameter.

[00127] A frequency in the first frequency band may be lower than the frequency of another frequency band different from the first frequency band in the first channel signal and in the second channel signal. Specifically, the first frequency band may be a frequency band with a lower frequency in the first channel signal and in the second channel signal. That is, a reverb gain parameter corresponding to a sub-band of a lower frequency band in the first channel signal and in the second channel signal may be determined as the target reverb gain parameter.

[00128] Alternatively, the first frequency band may be a frequency band with an intermediate frequency value in the first channel signal and the second channel signal (the frequencies of a portion of all the bands of Petition 870250032735, dated 04 / 24 / 2025, page 45 / 120 37 / 77 (frequency of the first channel signal and the second channel signal are greater than a frequency of the first frequency band and frequencies of another part of all frequency bands are less than the frequency of the first frequency band), that is, a reverberation gain parameter corresponding to a sub-band of the intermediate frequency value of the first channel signal and the second channel signal can be determined as the target reverberation gain parameter.

[00129] Optionally, the frequency box plurality is in a second frequency band of each of the first channel signal and the second channel, and a frequency of the second frequency band is higher than the frequency of another frequency band, different from the second frequency band, in the first channel signal and the second channel signal.

[00130] That is, the frequency box plurality is located in the second frequency band with a relatively high frequency. Therefore, the values ​​of the differences between the energy of the first channel signal and the energy of the second channel signal and the energy of the reduced signal can be conveniently determined by comparing the differences between the energy of the first channel signal and the energy of the second channel signal and the energy of the reduced signal in the frequency box plurality in the high-frequency part. Therefore, it is unnecessary to compare the differences between the energy of the first channel signal and the energy of the second channel signal and the energy of the reduced signal across the entire frequency band, thus simplifying the calculation process.

[00131] The values ​​of the differences between the energy of the first channel signal and the energy of the second channel signal and the energy of the reduced signal can be conveniently determined by comparing the differences between the energy of the first channel signal and the energy of the second channel signal and the energy of the reduced signal in the frequency plurality. Furthermore, the Petition 870250032735, dated 04 / 24 / 2025, page 46 / 120 The 38 / 77 target reverb gain parameter is determined based on the differences between the energy of the first channel signal and the energy of the second channel signal and the energy of the reduced signal, and it is unnecessary to compare the differences between both the energies of the first channel signal and the energy of the second channel signal and the energy of the reduced signal in all frequency bands.

[00132] Optionally, in one embodiment, the method in Figure 3 further includes: when the first difference value is less than or equal to the first limit, and the second difference value is less than or equal to the second limit, determine the reverberation gain parameters corresponding to all sub-bands of the first channel signal and the second channel signal as target reverberation gain parameters.

[00133] When the first difference value is less than or equal to the first limit, and the second difference value is less than or equal to the second limit, the differences between the energy of the first channel signal and the energy of the second channel signal and the energy of the reduced signal are relatively small. In this case, the coherence between the first channel signal and the second channel signal can be considered relatively large. To improve the reverberation sense of an output channel signal, the reverberation gain parameters corresponding to all sub-bands can be encoded.

[00134] When the differences between the energy of the first channel signal and the energy of the second channel signal and the energy of the reduced signal are relatively large, only the reverb gain parameters corresponding to some sub-bands can be encoded, to reduce bit overheads during encoding, and to avoid signal distortion caused during reverb processing as much as possible. When the differences between the energy of the first channel signal and the energy of the second channel signal and the energy of the signal Petition 870250032735, dated 04 / 24 / 2025, page 47 / 120 39 / 77 reduced frequencies are relatively small, and the signal distortion caused by reverb processing in the channel signal is very small. To obtain a better listening effect, the reverb gain parameters corresponding to all sub-bands can be encoded.

[00135] 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 based on the following formulas: diff_l_h = ΣΜ2Μ 1\mag_l[k] — mag_dmx[k]l (1) díff_r_h = ΣΜ2μi lmag_r[k] — mag_dmx[k] | (2) 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 an initial frequency box of the high frequency part, M2 is an final frequency box of the low frequency part, mag_l[k] is energy or an amplitude value of the left channel signal in a frequency box with an index k between M1 and M2, mag_r[k] is energy or an amplitude value of the right channel signal in the frequency box with an index k between M1 and M2, mag_dmx[k] is energy or an amplitude value of the reduced signal in the frequency box with an index k between M1 and M2, and mag_dmx[k] can be calculated using the reduced signal itself,Or it can be calculated based on the energy or amplitude values ​​of the right-channel signal and the left-channel signal.

[00136] After the first difference value and the second difference value are calculated based on formulas (1) and (2), frame-by-frame smoothing processing can be performed additionally on the first difference value and the second difference value (smoothing processing can be performed on the first difference value, the second difference value Petition 870250032735, dated 04 / 24 / 2025, page 48 / 120 40 / 77 difference and the difference values ​​calculated in a previous table) and then the target reverb gain parameter is determined using relationships between the first difference value and the second difference value obtained through smoothing processing and the predefined limits.

[00137] Optionally, in one embodiment, the determination of a target reverberation gain parameter that needs to be encoded in the reverberation gain parameters corresponding to the different sub-bands of the first channel signal and the second channel signal includes: determining the energy of N sub-bands of the reduced signal; determining M sub-bands from the N sub-bands, wherein the energy of any sub-band in the M sub-bands is greater than the energy of any sub-band in the NM sub-bands in the N sub-bands, except the M sub-bands, both M and N are integers greater than 0 and M is less than N; and determining the target reverberation gain parameter based on a magnitude ratio between the energy of the M sub-bands and the energy of the NM sub-bands.

[00138] The coherence between the first channel signal and the second channel signal can be determined based on the energy of different sub-bands of the reduced signal, and further the target reverb gain parameter that needs to be encoded is determined based on the coherence between the first channel signal and the second channel signal.

[00139] Specifically, determining the target reverberation gain parameter based on a magnitude relationship between the energy of the M sub-bands of the reduced signal and the energy of the NM sub-bands of the reduced signal includes: when a sum of the energy of the M sub-bands is greater than K times the sum of the energy of the NM sub-bands, determine that a reverberation gain parameter corresponding to a sub-band of a first frequency band of the first channel signal and the second channel signal is the target reverberation gain parameter, where K is a Petition 870250032735, dated 04 / 24 / 2025, page 49 / 120 41 / 77 is a real number greater than 0.

[00140] Determining the target reverberation gain parameter based on a magnitude relationship between the energy of the M sub-bands of the reduced signal and the energy of the NM sub-bands of the reduced signal includes: when an average value of the energy of the M sub-bands is greater than L times the average value of the energy of the NM sub-bands, determine that a reverberation gain parameter corresponding to a sub-band of a first frequency band of the first channel signal and the second channel signal is the target reverberation gain parameter, where L is a real number greater than 0.

[00141] It should be understood that K and L can have different values. More specifically, when M is greater than NM, K can be less than L, and when M is less than NM, K can be greater than L.

[00142] The energy of the N sub-bands of the reduced signal and the energy of the NM sub-bands of the reduced signal can be compared by comparing the average value of the energy of the M sub-bands of the reduced signal with the average value of the energy of the NM sub-bands of the reduced signal. To further reduce the complexity of the calculation, the sum of the energy of the M sub-bands of the reduced signal and the sum of the energy of the NM sub-bands of the reduced signal can be directly compared. In this way, a calculation process is simplified to a certain extent, and efficiency is improved.

[00143] When the energy differences between the M subbands of the reduced signal, with relatively high energy, and another subband with relatively low energy are relatively large, the difference between the first channel signal and the second channel signal can be considered relatively large. In this case, the reverberation gain parameters corresponding to subbands of some frequency bands in the first channel signal and the second channel signal can be determined as reverberation gain parameters. Petition 870250032735, dated 04 / 24 / 2025, page 50 / 120 42 / 77 target that need to be encoded. Specifically, the first frequency band can be a frequency band in the low-frequency portion of the first channel signal and the second channel signal, or it can be a frequency band in an intermediate-frequency portion of the first channel signal and the second channel signal.

[00144] Optionally, in one embodiment, the determination of a target reverberation gain parameter that needs to be encoded in the reverberation gain parameters corresponding to the different sub-bands of the first channel signal and the second channel signal includes: determining the energy of N sub-bands of the reduced signal; determining M sub-bands of the N sub-bands, wherein the energy of any sub-band in the M sub-bands is greater than the energy of any sub-band in the NM sub-bands in the N sub-bands, except the M sub-bands;and when an index value of a first sub-band in the M sub-bands is less than a predefined index value, determine that a reverberation gain parameter corresponding to a sub-band of a first frequency band of the first channel signal and the second channel signal is the target reverberation gain parameter, wherein a frequency of any frequency box of the first sub-band is greater than the frequency of any frequency box of another sub-band in the M sub-bands, except the first sub-band, and the first frequency band is part of all frequency bands of each of the first channel signals and the second channel signals.

[00145] When an index value of a maximum frequency sub-band in the M sub-bands with relatively high energy is less than the predefined index value, it can be considered that the energy distribution of the M sub-bands of the reduced signal is uneven, that is, the coherence between the first channel signal and the second channel signal is relatively small. In this case, only the gain parameters of Petition 870250032735, dated 04 / 24 / 2025, page 51 / 120 43 / 77 reverberation corresponding to sub-bands of some frequency bands needs to be encoded.

[00146] The reduced signal can be a broadband signal or an ultra-wideband signal. When the reduced signal is a broadband signal, the N sub-bands can all be sub-bands of the reduced signal, and when the reduced signal is an ultra-wideband signal, the N sub-bands can be sub-bands of the reduced signal in a broadband portion.

[00147] The M sub-bands can be determined from the N sub-bands based on the amplitude of each sub-band of the reduced signal, in addition to the magnitude of the energy of each sub-band of the reduced signal. Specifically, the M sub-bands can be determined based on the amplitude of each sub-band of the reduced signal, such that the amplitude of any sub-band in the M sub-bands is greater than the amplitude of any sub-band in the NM sub-bands.

[00148] A value of M can be a predefined value before encoding. For example, the reduced signal includes a total of 10 sub-bands. In this case, four sub-groups with maximum energy or amplitudes can be selected. When the energy or amplitude values ​​of the four sub-bands of the reduced signal (which can be a sum of the energy or amplitude values, or an average value of the energy or amplitude values) are greater than a predetermined multiple of the energy or amplitude values ​​of the six remaining sub-bands of the reduced signal, it is determined that the reverberation gain parameter corresponding to the first frequency band of the first channel signal and the second channel signal is the target reverberation gain parameter.

[00149] It should be understood that, in this embodiment of this application, the target reverberation gain parameter can be determined based on at least one of the following conditions. When at least one of the following conditions is valid, some Petition 870250032735, dated 04 / 24 / 2025, page 52 / 120 44 / 77 reverb gain parameters can be determined as target reverb gain parameters.

[00150] Condition 1: A difference value or difference values ​​between the energy of the first channel signal and / or the energy of the second channel signal and the energy of the reduced signal is / are greater than a predefined limit or limits.

[00151] Condition 2: The energy of the M sub-bands of the reduced signal is greater than a predetermined multiple of the energy of the NM sub-bands of the reduced signal.

[00152] Condition 3: The index value of the first sub-band in the M sub-bands is greater than the predefined index value.

[00153] A frequency of any spectral coefficient in the first sub-band is greater than the frequency of any spectral coefficient of another sub-band in the M sub-bands, except the first sub-band.

[00154] Optionally, in one embodiment, the determination of a target reverb gain parameter that needs to be encoded in the reverb gain parameters corresponding to the different sub-bands of the first channel signal and the second channel signal includes: determining the energy of N sub-bands of the reduced signal; determining J target sub-bands from the N sub-bands based on the energy of the N sub-bands, where the energy of any sub-band in the J target sub-bands is greater than the energy of another sub-band different from the J target sub-bands, N and J are integers greater than 0 and J is less than N; and determining reverb gain parameters corresponding to the J target sub-bands as target reverb gain parameters. J may be a predefined predetermined quantity.

[00155] A predetermined number of sub-bands is selected directly from all sub-bands based on the energy of each sub-band of the reduced signal, and the reverb gain parameters corresponding to the predetermined number of sub-bands are determined as parameters of Petition 870250032735, dated 04 / 24 / 2025, page 53 / 120 45 / 77 target reverb gain, so that a reverb gain parameter that needs to be encoded can be selected more flexibly.

[00156] Compared with a way of determining a reverberation gain parameter corresponding to a sub-band of a fixed frequency band as a target reverberation gain parameter, reverberation gain parameters corresponding to some sub-bands that may not be adjacent in the frequency domain can be selected directly and flexibly as target reverberation gain parameters.

[00157] Optionally, in one embodiment, the energy of the reduced signal is determined based on the energy of the first channel signal and the energy of the second channel signal. The energy of the reduced signal can be calculated based on the reduced signal itself, or it can be estimated or deduced using the energy of the first channel signal and the energy of the second channel signal. When the energy of the reduced signal is determined using the energy of the first channel signal and the energy of the second channel signal, a calculation process can be simplified to a certain extent.

[00158] Figure 4 is a schematic flowchart of a multichannel signal decoding method according to one embodiment of this application. The method in Figure 4 can be performed by a decoder-side device or a decoder. The decoding method in Figure 4 corresponds to the encoding method in Figure 3. The decoding method in Figure 4 can be used to decode the bitstream obtained by encoding the first channel signal and the second channel signal in the encoding method in Figure 3. The method shown in Figure 4 includes the following steps.

[00159] 410. Receive a bit stream.

[00160] 420. Obtain a reduced signal from a first channel signal and a second channel signal in a data source. Petition 870250032735, dated 04 / 24 / 2025, page 54 / 120 46 / 77 parameter indication and multichannel signal based on bitstream, where parameter indication information is used to indicate a target reverb gain parameter encoded in the corresponding reverb gain parameters for different sub-bands of the first channel signal and the second channel signal.

[00161] The parameter indication information can indicate, using a flag bit, a sub-band corresponding to the target reverb gain parameter. For example, each of the first channel signal and the second channel signal includes 10 sub-bands (sub-bands whose index numbers are 0 to 9), the parameter indication information includes 10 flag bits, and the 10 flag bits successively correspond to the 10 sub-bands of each multichannel signal. When a flag bit corresponding to a sub-band is 1, a reverb gain parameter corresponding to the sub-band is a target reverb gain parameter that needs to be encoded. If a flag bit corresponding to a sub-band is 0, a reverb gain parameter corresponding to the sub-band is not a target reverb gain parameter.Specifically, if the signaling bits corresponding to the sub-bands whose index numbers are 0 to 5 are 1, and the signaling bits corresponding to the sub-bands whose index numbers are 6 to 9 are 0, the decoder side only decodes the reverb gain parameters corresponding to the sub-bands whose index numbers are 1 to 5 during decoding.

[00162] 430. Obtain the target reverb gain parameter in the bitstream, according to the parameter indication information.

[00163] 440. Determine the first channel signal and the second channel signal based on the reduced signal and the target reverb gain parameter. Petition 870250032735, dated 04 / 24 / 2025, page 55 / 120 47 / 77

[00164] In this application, the target reverb gain parameter encoded by an encoder can be determined using the parameter indication information, and then reverb processing is performed on a corresponding sub-band of the first channel signal and second channel signal based on the target reverb gain parameter.

[00165] It should be understood that, before reverb processing is performed on the first channel signal and the second channel signal based on the target reverb gain parameter, the decoder side still obtains a decoherence signal, and corrects the decoherence signal using the target reverb gain parameter. Then, reverb processing can be further performed on the first channel signal and the second channel signal using the corrected decoherence signal.If each of the first and second channel signals includes 10 sub-bands (sub-bands with index numbers 0 to 9), and the reverb gain parameters corresponding to the sub-bands with index numbers 0 to 5 are the target reverb gain parameters, the decoder side obtains only the reverb gain parameters corresponding to the sub-bands with index numbers 0 to 5 and does not obtain reverb gain parameters corresponding to the sub-bands with index numbers 6 to 10. Therefore, the decoder side performs reverb processing only on the sub-bands with index numbers 0 to 5 of the first and second channel signals, and does not perform reverb processing on the sub-bands with index numbers 6 to 10 of the first and second channel signals.

[00166] When the first channel signal and the second channel signal include a left channel signal and a right channel signal, the determination of the first channel signal and the second channel signal based on the reduced signal and the gain parameter. Petition 870250032735, dated 04 / 24 / 2025, page 56 / 120 48 / 77 target reverb includes: determining a coherence signal based on a reduced signal and a target reverb gain parameter from a frame prior to the current frame; and determining the left channel signal and the right channel signal based on the decoherence signal and a reduced signal from the current frame.

[00167] For example, the first channel signal and the second channel signal include a left channel signal and a right channel signal. The reduced signal of the current frame is dmx, the reduced signal of the frame prior to the current frame is dmx_pred, and a target reduced gain parameter is the gain. Then, a coherence signal tmp is first obtained based on dmx_pred and the gain. Next, the left channel signal L = dmx + tmp and the right channel signal R = dmx - tmp are obtained based on the reduced signal of the current frame and the decoherence signal.

[00168] With reference to Figure 5 and Figure 6, the following describes in detail an entire process of the multichannel signal encoding method and decoding method in the modes of this application using an example of a left channel signal and a right channel signal.

[00169] Figure 6 is a schematic flowchart of a multichannel signal coding method according to an embodiment of this application. In Figure 5, a multichannel signal includes 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.

[00170] 510. Calculate a spatial parameter of the left channel signal and a spatial parameter of the right channel signal.

[00171] Spatial parameters include reverberation gain parameters corresponding to sub-bands of the left channel signal and the right channel signal, and other spatial parameters (such as an IC, an ILD, an ITD and an IPD).

[00172] 520. Perform signal reduction processing. Petition 870250032735, dated 04 / 24 / 2025, page 57 / 120 49 / 77 left channel (represented by L in the figure) and in the right channel signal (represented by R in the figure) to obtain a reduced signal.

[00173] 530. Adaptively select a target reverb gain parameter that needs to be encoded into the reverb gain parameters corresponding to the subbands of the left channel signal and the right channel signal.

[00174] 540. Quantize separately the target reverb gain parameter and the reduced signal to obtain a bitstream.

[00175] Figure 6 is a schematic flowchart of a multichannel signal decoding method according to one embodiment of this application. In Figure 6, a multichannel signal includes a left-channel signal and a right-channel signal. The bitstream generated through encoding in Figure 5 can be decoded in Figure 6. A decoding process in Figure 6 specifically includes the following steps: 610. Obtain a bitstream of the left-channel and right-channel signals. 620. Decode the bit stream to obtain a reduced signal. 630. Obtain flag information from the bitstream and determine, based on a flag bit, a target reverb gain parameter that needs to be decoded. 640. Decode the reverb gain parameters corresponding to the sub-bands, for reverb processing, in the left channel signal and the right channel signal, and other spatial parameters (such as an IC, an ILD, an ITD and an IPD). 640. Perform subsequent processing (e.g., soft filtering) on ​​the spatial parameters obtained by decoding. 650. Perform signal-based augmentation processing. Petition 870250032735, dated 04 / 24 / 2025, page 58 / 120 50 / 77 reduced and in the reverberation gain parameters that are obtained by decoding, to obtain the left channel signal and the right channel signal.

[00176] After the augmentation processing is performed to obtain the left channel signal and the right channel signal, reverb processing can be performed separately on the left channel signal and the right channel signal based on a coherence signal.

[00177] In the method shown in Figure 6, reverb processing is performed on the left channel signal and the right channel signal based on the target reverb gain parameter obtained by decoding, and reverb processing can be performed on some sub-bands of the left channel signal and the right channel signal based on the target reverb gain parameter, thus ensuring the quality of a channel signal obtained after reverb processing.

[00178] Figure 7 is a schematic flowchart of a multichannel signal encoding method according to one embodiment of this application. The method in Figure 7 can be implemented by an encoder-side device or an encoder. The method shown in Figure 7 includes the following steps.

[00179] 710. Determine a reduced signal of a first channel signal and a second channel signal in a multichannel signal, and reverb gain parameters corresponding to different sub-bands of the first channel signal and the second channel signal.

[00180] This application does not limit a sequence between a reduced signal generation process and a process for generating the reverberation gain parameters corresponding to the different sub-bands of the first channel signal and the second channel signal. The processes can be performed simultaneously or sequentially.

[00181] Specifically, the reduced signal can be obtained Petition 870250032735, dated 04 / 24 / 2025, page 59 / 120 51 / 77 through performing reduction processing on the first channel signal and the second channel signal. Spatial parameter analysis is performed on the first channel signal and the second channel signal to obtain spatial parameters of the first channel signal and the second channel signal. The spatial parameters include a reverberation gain parameter corresponding to each sub-band of the first channel signal and the second channel signal, and an IC, an ILD, an ITD, an IPD and the like between the first channel signal and the second channel signal.

[00182] 720. Determine, based on the energy of N sub-bands of the reduced signal, a target reverberation gain parameter that needs to be encoded into the reverberation gain parameters corresponding to the different sub-bands of the first channel signal and the second channel signal, where N is an integer greater than 0.

[00183] The energy of a plurality of sub-bands of the reduced signal can be calculated based on the reduced signal itself, or the energy of the reduced signal can be estimated or deduced using the energy of the first channel signal and the energy of the second channel signal. When the energy of the reduced signal is determined using the energy of the first channel signal and the energy of the second channel signal, a calculation process can be simplified to a certain extent.

[00184] Specifically, the J target sub-bands can be determined from the N sub-bands based on the energy of the N sub-bands of the reduced signal. The energy of any sub-band in the J target sub-bands is greater than the energy of another sub-band different from the J target sub-bands, N and J are integers greater than 0, and J is less than N. Reverb gain parameters corresponding to the J target sub-bands are determined as target reverb gain parameters.

[00185] A predetermined number of sub-bands is Petition 870250032735, dated 04 / 24 / 2025, page 60 / 120 52 / 77 is selected directly from all sub-bands based on the energy of each sub-band of the reduced signal, and the reverb gain parameters corresponding to the predetermined number of sub-bands are determined as target reverb gain parameters, so that a reverb gain parameter that needs to be encoded can be selected more flexibly.

[00186] 730. Encode the reduced signal and the target reverb gain parameter.

[00187] Furthermore, the reduced signal can be a broadband signal or an ultra-wideband signal. When the reduced signal is a broadband signal, the plurality of sub-bands can be all the sub-bands of the reduced signal, and when the reduced signal is an ultra-wideband signal, the plurality of sub-bands can be sub-bands of the reduced signal in a broadband portion.

[00188] In this application, a specific number of sub-bands are selected directly from all sub-bands based on the energy of each sub-band of the reduced signal, so that a reverb gain parameter that needs to be encoded can be selected more flexibly. Furthermore, compared to a method of determining a reverb gain parameter corresponding to a sub-band of a fixed frequency band as a target reverb gain parameter, reverb gain parameters corresponding to some sub-bands that may not be adjacent in the frequency domain can be directly selected as target reverb gain parameters.

[00189] Figure 8 is a schematic flowchart of a multichannel signal decoding method according to an embodiment of this application. The method in Figure 8 can be implemented by a decoder-side device or a decoder. The decoding method in Figure 8 corresponds to the method Petition 870250032735, dated 04 / 24 / 2025, page 61 / 120 53 / 77 encoding in Figure 7. The decoding method in Figure 8 can be used to decode the bitstream obtained by encoding the first channel signal and the second channel signal in the encoding method in Figure 7. The method in Figure 8 includes the following steps.

[00190] 810. Receive a bit stream.

[00191] 820. Obtain a reduced signal from a first channel signal and a second channel signal into a multichannel signal based on the bit stream.

[00192] Specifically, the bit stream of the first channel signal and the second channel signal can be demultiplexed first, and then the bit stream corresponding to the reduced signal can be decoded to obtain the reduced signal.

[00193] 830. Determine, based on the energy of N sub-bands of the reduced signal, a target reverberation gain parameter encoded in reverberation gain parameters corresponding to different sub-bands of the first channel signal and the second channel signal, where N is an integer greater than 0.

[00194] Specifically, J target sub-bands can be determined from the N sub-bands based on the energy of the N sub-bands. The energy of any sub-band in the J target sub-bands is greater than the energy of another sub-band different from the J target sub-bands, N and J are integers greater than 0 and J is less than N. Reverb gain parameters corresponding to the J target sub-bands are determined as target reverb gain parameters.

[00195] It should be understood that both the encoder and decoder sides can determine, according to the same rule based on the energy of a plurality of sub-bands of the reduced signal, the target reverberation gain parameter encoded in the reverberation gain parameters corresponding to the different sub-bands of the first signal. Petition 870250032735, dated 04 / 24 / 2025, page 62 / 120 54 / 77 channel and the second channel signal. In this way, the encoder side may not need to specify a reverb gain parameter encoded in the bitstream, but the decoder side can determine the reverb gain parameter encoded using the same rule.

[00196] For example, the encoder side determines, based on the energy of the sub-band plurality of the reduced signal, that the reverberation gain parameters corresponding to the sub-bands whose index numbers are 0 to 5 are the target reverberation gain parameters, and the encoder side quantizes the reverberation gain parameters corresponding to the sub-bands whose index numbers are 0 to 5, records the quantized reverberation gain parameters in the bitstream, and transmits the bitstream to the decoder side.After receiving the bit stream, the decoder side determines, also based on the energy of the sub-band plurality of the reduced signal, that the reverberation gain parameters corresponding to the sub-bands whose index numbers are from 0 to 5 are the target reverberation gain parameters, and then the decoder side decodes the reverberation gain parameters corresponding to the sub-bands whose index numbers are from 0 to 5.

[00197] 840. Determine the target reverb gain parameter based on the bit stream.

[00198] Other encoded spatial parameters can be obtained from the bitstream, such as an IC, an ILD, an ITD, and an IPD, in addition to the target reverb gain parameter.

[00199] 850. Determine the first channel signal and the second channel signal based on the reduced signal and the target reverb gain parameter.

[00200] In this request, the decoder side can directly determine, based on the energy of the plurality of sub-bands of Petition 870250032735, dated 04 / 24 / 2025, page 63 / 120 55 / 77 reduced signal, the target reverberation gain parameter encoded in the reverberation gain parameters corresponding to the different sub-bands of the first channel signal and the second channel signal, so that the bits occupied by the decoder side to transmit indication information to indicate the encoded target reverberation gain parameter are reduced and the signaling overheads can be reduced to some extent.

[00201] Specifically, before reverb processing is performed on the first channel signal and the second channel signal based on the target reverb gain parameter, the decoder side still obtains a decoherence signal, and corrects the decoherence signal using the target reverb gain parameter (the decoherence signal can be obtained by delaying the reduced signal). Then, reverb processing can still be performed on the first channel signal and the second channel signal using the corrected decoherence signal.If each of the first and second channel signals includes 10 sub-bands, and the reverb gain parameters corresponding to the sub-bands with index numbers 1, 3, 5, and 7 are the target reverb gain parameters, the decoder side obtains only the reverb gain parameters corresponding to the sub-bands with index numbers 1, 3, 5, and 7, and does not obtain reverb gain parameters corresponding to the sub-bands with index numbers 2, 4, 6, 8, 9, and 10. Therefore, the decoder side performs the reverb processing only on the sub-bands with index numbers 1, 3, 5, and 7 of the first and second channel signals, and does not perform reverb processing on the sub-bands with index numbers 2, 4, 6, 8, 9, and 10 of the first and second channel signals.

[00202] When the first channel signal and the second signal Petition 870250032735, dated 04 / 24 / 2025, page 64 / 120 56 / 77 channel includes a left channel signal and a right channel signal, the determination of the first channel signal and the second channel signal based on the reduced signal and the target reverberation gain parameter includes: determining a decoherence signal based on a reduced signal and a target reverberation gain parameter from a frame prior to a current frame; and determining the left channel signal and the right channel signal based on the decoherence signal and a reduced signal from the current frame.

[00203] With reference to Figure 9 and Figure 10, the following describes in detail an entire process of the multichannel signal encoding method and decoding method in the modalities of this application, using an example of a left channel signal and a right channel signal.

[00204] Figure 9 is a schematic flowchart of a multichannel signal coding method according to an embodiment of this application. In Figure 9, a multichannel signal includes 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.

[00205] 910. Calculate a spatial parameter of the left channel signal and a spatial parameter of the right channel signal.

[00206] Spatial parameters include reverberation gain parameters corresponding to sub-bands of the left channel signal and the right channel signal, and other spatial parameters (such as an IC, an ILD, an ITD and an IPD).

[00207] 920. Perform reduction 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 reduced signal.

[00208] 930. Determine the energy of different sub-bands of the reduced signal.

[00209] The energy of the reduced signal can be calculated with Petition 870250032735, dated 04 / 24 / 2025, page 65 / 120 57 / 77 based on the reduced signal itself, or it can be estimated or deduced based on the left channel signal energy and the right channel signal energy.

[00210] 940. Adaptively select, based on the energy of the different sub-bands of the reduced signal, a target reverb gain parameter that needs to be encoded in the reverb gain parameters corresponding to the sub-bands of the left channel signal and the right channel signal.

[00211] 950. Quantize the target reverb gain parameter and the reduced signal to obtain a bitstream.

[00212] Figure 10 is a schematic flowchart of a multichannel signal decoding method according to one embodiment of this application. In Figure 10, a multichannel signal includes a left-channel signal and a right-channel signal. The bitstream generated through encoding in Figure 9 can be decoded in Figure 10. A decoding process in Figure 10 specifically includes the following steps: 1010. Obtain a bitstream of the left-channel and right-channel signals. 1020. Decode the bit stream to obtain a reduced signal. 1030. Determine the energy of different sub-bands of the reduced signal.

[00213] The energy of the reduced signal can be calculated based on the reduced signal itself, or it can be estimated or deduced based on the energy of the left channel signal and the energy of the right channel signal.

[00214] 1040. Adaptively select, based on the energy of the different sub-bands of the reduced signal, sub-bands for reverb processing, from the left channel signal and the right channel signal.

[00215] 1050. Decode the gain parameters of Petition 870250032735, dated 04 / 24 / 2025, page 66 / 120 58 / 77 reverberation corresponding to the selected sub-bands, for reverberation processing, of the left channel signal and the right channel signal, and other spatial parameters (such as an IC, an ILD, an ITD and an IPD).

[00216] 1060. Perform boost processing based on the reduced signal and reverb gain parameters obtained by decoding (the reverb gain parameter is a reverb gain parameter adjusted by the encoder side), to obtain the left channel signal and the right channel signal.

[00217] After the augmentation processing is performed to obtain the left channel signal and the right channel signal, reverb processing can be performed separately on the left channel signal and the right channel signal based on a coherence signal.

[00218] In the method shown in Figure 10, reverb processing is performed on the left channel signal and the right channel signal based on the target reverb gain parameter obtained by decoding, and reverb processing can be performed on some sub-bands of the left channel signal and the right channel signal based on the target reverb gain parameter, thus ensuring the quality of a channel signal obtained after reverb processing.

[00219] The preceding descriptions describe the multichannel signal encoding method and the multichannel signal decoding method in the embodiments of this application in detail with reference to Figures 3 to 10. The following describes an encoder and a decoder in the embodiments of this application with reference to Figures 11 to 18. It should be understood that the encoder and decoder in Figures 8 to 13 may implement the steps performed by the encoder and decoder in the encoding method and the decoding method in the embodiments of this application. For reasons of Petition 870250032735, dated 04 / 24 / 2025, page 67 / 120 59 / 77 For brevity, repeated descriptions are correctly omitted below.

[00220] Figure 11 is a schematic block diagram of an encoder according to an embodiment of this application. An 1100 encoder in Figure 11 includes: a processing unit 1110, configured to determine a reduced signal of a first channel signal and a second channel signal into a multichannel signal, and reverb gain parameters corresponding to different sub-bands of the first channel signal and the second channel signal, wherein the processing unit 1110 is further configured to determine a target reverb gain parameter that needs to be encoded into the reverb gain parameters corresponding to the different sub-bands of the first channel signal and the second channel signal; and the processing unit 1110 is further configured to generate parameter indication information, wherein the parameter indication information is used to indicate a sub-band corresponding to the target reverb gain parameter;and an 1120 encoding unit, configured to encode the target reverb gain parameter, the parameter indication information, and the reduced signal to generate a bitstream.

[00221] In this application, when the first channel signal and the second channel signal are being encoded, the reverb gain parameters corresponding to only some subbands of the first channel signal and the second channel signal can be encoded. Compared to a prior art method, in which the reverb gain parameters corresponding to all subbands of the first channel signal and the second channel signal need to be encoded, bit overheads can be reduced to some extent and encoding efficiency can be improved. Specifically, Petition 870250032735, dated 04 / 24 / 2025, page 68 / 120 60 / 77 a number of saved bits can be used to encode another parameter or allocate more bits to the reduced signal if the reverb gain parameters corresponding to some sub-bands are encoded, thus improving the overall encoding performance.

[00222] The 1100 encoder can match the multichannel signal encoding method in Figure 3, and the 1100 encoder can perform the multichannel signal encoding method in Figure 3.

[00223] Optionally, in one embodiment, the processing unit 1110 is specifically configured to determine the target reverb gain parameter based on at least one coherence between the energy of the first channel signal and the energy of the reduced signal and coherence between the energy of the second channel signal and the energy of the reduced signal.

[00224] Optionally, in one embodiment, each of the first channel signal and the second channel signal includes a plurality of frequency boxes, and the processing unit 1110 is specifically configured to: determine a first difference value between the energy of the first channel signal and the energy of the reduced signal, wherein the first difference value is used to indicate a sum of the absolute values ​​of the difference values ​​between the energy of the first channel signal and the energy of the reduced signal in the plurality of frequency boxes; and when the first difference value is greater than a first threshold, determine that a reverberation gain parameter corresponding to a sub-band of a first frequency band is the target reverberation gain parameter, wherein the first frequency band is part of all frequency bands of each of the first channel signal and the second channel signal.

[00225] Optionally, in one embodiment, each of the first channel signal and the second channel signal includes a plurality Petition 870250032735, dated 04 / 24 / 2025, page 69 / 120 61 / 77 of frequency boxes, and processing unit 1110 is specifically configured to: determine a second difference value between the energy of the second channel signal and the energy of the reduced signal, wherein the second difference value is used to indicate a sum of the absolute values ​​of the difference values ​​between the energy of the second channel signal and the energy of the reduced signal in the plurality of frequency boxes; and when the second difference value is greater than a second threshold, determine that a reverberation gain parameter corresponding to a sub-band of a first frequency band is the target reverberation gain parameter, wherein the first frequency band is part of all frequency bands of each of the first channel signal and the second channel signal.

[00226] Optionally, in one embodiment, each of the first channel signal and the second channel signal includes a plurality of frequency boxes, and the processing unit 1110 is specifically configured to: determine a first difference value between the energy of the first channel signal and the energy of the reduced signal, wherein the first difference value is used to indicate a sum of the absolute values ​​of the difference values ​​between the energy of the first channel signal and the energy of the reduced signal in the plurality of frequency boxes; determine a second difference value between the energy of the second channel signal and the energy of the reduced signal, wherein the second difference value is used to indicate a sum of the absolute values ​​of the difference values ​​between the energy of the second channel signal and the energy of the reduced signal in the plurality of frequency boxes;and when the first difference value is greater than a first limit and the second difference value is greater than a second limit, determine that a reverberation gain parameter corresponding to a subband of a first frequency band is the gain parameter; Petition 870250032735, dated 04 / 24 / 2025, pp. 70 / 120 62 / 77 target reverberation, where the first frequency band is a part of all the frequency bands of each of the first channel signal and the second channel.

[00227] Optionally, in one embodiment, a frequency in the first frequency band is lower than the frequency in another frequency band different from the first frequency band in the first channel signal and in the second channel signal.

[00228] Optionally, in one embodiment, the frequency box plurality is in a second frequency band of each of the first channel signal and second channel signal, and a frequency of the second frequency band is higher than the frequency of another frequency band, different from the second frequency band, in the first channel signal and in the second channel signal.

[00229] Optionally, in one embodiment, the processing unit 1110 is specifically configured to: determine the energy of N sub-bands of the reduced signal; determine M sub-bands of the N sub-bands, where the energy of any sub-band in the M sub-bands is greater than the energy of any sub-band in the NM sub-bands in the N sub-bands, except the M sub-bands, both M and N are integers greater than 0 and M is less than N; and determine the target reverberation gain parameter based on a magnitude ratio between the energy of the M sub-bands of the reduced signal and the energy of the NM sub-bands of the reduced signal.

[00230] Optionally, in one embodiment, the processing unit 1110 is specifically configured to: when the sum of the energy of the M sub-bands is greater than L times the sum of the energy of the NM sub-bands, determine that a reverberation gain parameter corresponding to a sub-band of a first frequency band of the first channel signal and the second channel signal is the target reverberation gain parameter, wherein the first frequency band is part of all Petition 870250032735, dated 04 / 24 / 2025, page 71 / 120 63 / 77 are the frequency bands of each of the first channel signal and the second channel, and L is a real number greater than 0.

[00231] Optionally, in one embodiment, the processing unit 1110 is specifically configured to: determine the energy of N sub-bands of the reduced signal; determine M sub-bands of the N sub-bands, where the energy of any sub-band in the M sub-bands is greater than the energy of any sub-band in the NM sub-bands in the N sub-bands, except the M sub-bands;and when an index value of a first sub-band in the M sub-bands is less than a predefined index value, determine that a reverberation gain parameter corresponding to a sub-band of a first frequency band of the first channel signal and the second channel signal is the target reverberation gain parameter, wherein a frequency of any frequency box in the first sub-band is greater than the frequency of any frequency box in another sub-band in the M sub-bands, except the first sub-band, and the first frequency band is part of all frequency bands of each of the first channel signal and the second channel signal.

[00232] Optionally, in one embodiment, the processing unit 1110 is specifically configured to: determine J target sub-bands from the N sub-bands, where the energy of any sub-band in the J target sub-bands is greater than the energy of another sub-band different from the J target sub-bands, both N and J are integers greater than 0 and J is less than N; and determine reverberation gain parameters corresponding to the J target sub-bands as target reverberation gain parameters.

[00233] Optionally, in one embodiment, the reduced signal energy is determined based on the energy of the first channel signal and the energy of the second channel signal.

[00234] Figure 12 is a schematic block diagram of a decoder according to an embodiment of this application. One Petition 870250032735, dated 04 / 24 / 2025, page 72 / 120 The 64 / 77 decoder 1200 in Figure 12 includes: A 1210 acquisition unit, configured to receive a bitstream, wherein the 1210 acquisition unit is further configured to obtain a reduced signal from a first channel signal and a second channel signal into a parameter indication information and multichannel signal based on the bitstream, wherein the parameter indication information is used to indicate a target reverberation gain parameter encoded in reverberation gain parameters corresponding to different sub-bands of the first channel signal and the second channel signal; and the 1210 acquisition unit is further configured to obtain the target reverberation gain parameter from the bitstream according to the parameter indication information; and a 1220 processing unit, configured to determine the first channel signal and the second channel signal based on the reduced signal and the target reverberation gain parameter.

[00235] In this application, the target reverb gain parameter encoded by an encoder can be determined using the parameter indication information, and then reverb processing is performed on a corresponding sub-band of the first channel signal and second channel signal based on the target reverb gain parameter.

[00236] The 1200 decoder can be matched to the multichannel signal decoding method in Figure 4, and the 1200 decoder can perform the multichannel signal decoding method in Figure 4.

[00237] Figure 13 is a schematic block diagram of an encoder according to an embodiment of this application. An encoder 1300 in Figure 13 includes: a 1310 processing unit, configured to determine a reduced signal from a first channel signal and a Petition 870250032735, dated 04 / 24 / 2025, page 73 / 120 65 / 77 second channel signal in a multichannel signal and reverberation gain parameters corresponding to different sub-bands of the first channel signal and the second channel signal, wherein processing unit 1310 is further configured to determine, based on the energy of N sub-bands of the reduced signal, a target reverberation gain parameter that needs to be encoded into the reverberation gain parameters corresponding to the different sub-bands of the first channel signal and the second channel signal, where N is an integer greater than 0; and an encoding unit 1320, configured to encode the reduced signal and the target reverberation gain parameter. In this request, a specific number of sub-bands are selected directly from all sub-bands based on the energy of each sub-band of the reduced signal, so that a reverb gain parameter that needs to be encoded can be selected with more flexibility.

[00238] The 1300 encoder can be matched to the multichannel signal encoding method in Figure 7, and the 1300 encoder can perform the multichannel signal encoding method in Figure 7.

[00239] Optionally, in one embodiment, the processing unit 1310 is specifically configured to: determine J target sub-bands from the N sub-bands, where the energy of any sub-band in the J target sub-bands is greater than the energy of another sub-band different from the J target sub-bands, both N and J are integers greater than 0 and J is less than N; and determine reverberation gain parameters corresponding to the J target sub-bands as target reverberation gain parameters.

[00240] Figure 14 is a schematic block diagram of a decoder according to an embodiment of this application. A 1400 decoder in Figure 14 includes: a first acquisition unit 1410, configured for Petition 870250032735, dated 04 / 24 / 2025, page 74 / 120 66 / 77 receive a bit stream; a first 1420 processing unit, configured to determine a reduced signal from the first channel signal and a second channel signal into a multichannel signal based on the bit stream; a second processing unit 1430, configured to determine, based on the energy of N sub-bands of the reduced signal, a target reverberation gain parameter encoded in the reverberation gain parameters corresponding to different sub-bands of the first channel signal and the second channel signal, where N is an integer greater than 0; a third processing unit 1440, configured to determine the target reverb gain parameter based on the bit stream; and a fourth processing unit 1450, configured to determine the first channel signal and the second channel signal based on the reduced signal and the target reverb gain parameter.

[00241] In this application, one side of the decoder can directly determine, based on the energy of a plurality of sub-bands of the reduced signal, the target reverberation gain parameter encoded in the reverberation gain parameters corresponding to the different sub-bands of the first channel signal and the second channel signal, so that the bits occupied by the decoder side to transmit indication information to indicate the encoded target reverberation gain parameter are reduced, and the signaling overheads can be reduced to a certain extent.

[00242] The 1400 decoder can be matched to the multichannel signal decoding method in Figure 8, and the 1400 decoder can perform the multichannel signal decoding method in Figure 8.

[00243] Optionally, in one modality, the first unit Petition 870250032735, dated 04 / 24 / 2025, page 75 / 120 67 / 77 processing 1420 is specifically configured to: determine J target sub-bands from N sub-bands based on the energy of the N sub-bands, where the energy of any sub-band in the J target sub-bands is greater than the energy of another sub-band different from the J target sub-bands, N and J are integers greater than 0 and J is less than N; and determine reverb gain parameters corresponding to the J target sub-bands as target reverb gain parameters.

[00244] Figure 15 is a schematic block diagram of an encoder according to an embodiment of this application. An encoder 1500 in Figure 15 includes: A 1510 memory, configured to store a program; and a 1520 processor, configured to execute the program, and when the program is executed, the 1520 processor is configured to determine a reduced signal of a first channel signal and a second channel signal into a multichannel signal and reverb gain parameters corresponding to different sub-bands of the first channel signal and the second channel signal; determine a target reverb gain parameter that needs to be encoded into the reverb gain parameters corresponding to the different sub-bands of the first channel signal and the second channel signal; generate parameter indication information, wherein the parameter indication information is used to indicate a sub-band corresponding to the target reverb gain parameter; and encode the target reverb gain parameter, the parameter indication information, and the reduced signal to generate a bitstream.

[00245] In this application, when the first channel signal and the second channel signal are being encoded, the reverberation gain parameters corresponding to only a few subbands of the first channel signal and the second channel signal can be encoded. Compared with a method in the prior art, where the reverberation gain parameters Petition 870250032735, dated 04 / 24 / 2025, page 76 / 120 Since the 68 / 77 bits corresponding to all sub-bands of the first channel signal and the second channel signal need to be encoded, bit overheads can be reduced to some extent and encoding efficiency can be improved. Specifically, a number of bits saved can be used to encode another parameter or allocate more bits to the reduced signal if the reverb gain parameters corresponding to some sub-bands are encoded, thus improving the overall encoding performance.

[00246] The 1500 encoder can match the multichannel signal encoding method in Figure 3, and the 1500 encoder can perform the multichannel signal encoding method in Figure 3.

[00247] Optionally, in one embodiment, the 1520 processor is specifically configured to determine the target reverb gain parameter based on at least one coherence between the energy of the first channel signal and the energy of the reduced signal and coherence between the energy of the second channel signal and the energy of the reduced signal.

[00248] Optionally, in one embodiment, each of the first channel signal and the second channel signal includes a plurality of frequency boxes, and the 1520 processor is specifically configured to: determine a first difference value between the energy of the first channel signal and the energy of the reduced signal, wherein the first difference value is used to indicate a sum of the absolute values ​​of the difference values ​​between the energy of the first channel signal and the energy of the reduced signal in the plurality of frequency boxes; and when the first difference value is greater than a first threshold, determine that a reverberation gain parameter corresponding to a sub-band of a first frequency band is the target reverberation gain parameter, wherein the first frequency band is part of all bands of Petition 870250032735, dated 04 / 24 / 2025, p. 77 / 120 69 / 77 frequency of each of the first channel signal and the second channel signal.

[00249] Optionally, in one embodiment, each of the first channel signal and the second channel signal includes a plurality of frequency boxes, and the 1520 processor is specifically configured to: determine a second difference value between the energy of the second channel signal and the energy of the reduced signal, wherein the second difference value is used to indicate a sum of the absolute values ​​of the difference values ​​between the energy of the second channel signal and the energy of the reduced signal in the plurality of frequency boxes; and when the second difference value is greater than a second threshold, determine that a reverberation gain parameter corresponding to a sub-band of a first frequency band is the target reverberation gain parameter, wherein the first frequency band is part of all frequency bands of each of the first channel signal and the second channel signal.

[00250] Optionally, in one embodiment, each of the first channel signal and the second channel signal includes a plurality of frequency boxes, and the 1520 processor is specifically configured to: determine a first difference value between the energy of the first channel signal and the energy of the reduced signal, wherein the first difference value is used to indicate a sum of the absolute values ​​of the difference values ​​between the energy of the first channel signal and the energy of the reduced signal in the plurality of frequency boxes; determine a second difference value between the energy of the second channel signal and the energy of the reduced signal, wherein the second difference value is used to indicate a sum of the absolute values ​​of the difference values ​​between the energy of the second channel signal and the energy of the reduced signal in the plurality of frequency boxes; and when the first difference value is greater than Petition 870250032735, dated 04 / 24 / 2025, page 78 / 120 70 / 77 a first limit and the second difference value is greater than a second limit, determine that a reverberation gain parameter corresponding to a sub-band of a first frequency band is the target reverberation gain parameter, where the first frequency band is a part of all frequency bands of each of the first channel signal and the second channel.

[00251] Optionally, in one embodiment, a frequency in the first frequency band is lower than the frequency in another frequency band different from the first frequency band in the first channel signal and in the second channel signal.

[00252] Optionally, in one embodiment, the frequency box plurality is in a second frequency band of each of the first channel signal and second channel signal, and a frequency of the second frequency band is higher than the frequency of another frequency band, different from the second frequency band, in the first channel signal and in the second channel signal.

[00253] Optionally, in one embodiment, the 1520 processor is specifically configured to: determine the energy of N sub-bands of the reduced signal; determine M sub-bands of the N sub-bands, where the energy of any sub-band in the M sub-bands is greater than the energy of any sub-band in the NM sub-bands in the N sub-bands, except the M sub-bands, both M and N are integers greater than 0 and M is less than N; and determine the target reverb gain parameter based on a magnitude ratio between the energy of the M sub-bands and the energy of the NM sub-bands.

[00254] Optionally, in one embodiment, the 1520 processor is specifically configured to: when the sum of the energy of the M sub-bands is greater than L times the sum of the energy of the NM sub-bands, determine that a reverb gain parameter corresponding to a sub-band of a first Petition 870250032735, dated 04 / 24 / 2025, page 79 / 120 71 / 77 frequency band of the first channel signal and the second channel signal is the target reverberation gain parameter, where the first frequency band is part of all frequency bands of each of the first and second channel signals, and L is a real number greater than 0.

[00255] Optionally, in one embodiment, the 1520 processor is specifically configured to: determine the energy of N sub-bands of the reduced signal; determine M sub-bands of the N sub-bands, where the energy of any sub-band in the M sub-bands is greater than the energy of any sub-band in the NM sub-bands in the N sub-bands, except the M sub-bands;and when an index value of a first sub-band in the M sub-bands is less than a predefined index value, determine that a reverberation gain parameter corresponding to a sub-band of a first frequency band of the first channel signal and the second channel signal is the target reverberation gain parameter, wherein a frequency of any frequency box in the first sub-band is greater than the frequency of any frequency box in another sub-band in the M sub-bands, except the first sub-band, and the first frequency band is part of all frequency bands of each of the first channel signal and the second channel signal.

[00256] Optionally, in one embodiment, the 1520 processor is specifically configured to: determine the energy of N sub-bands of the reduced signal; determine J target sub-bands from the N sub-bands based on the energy of the N sub-bands, where the energy of any sub-band in the J sub-bands is greater than the energy of another sub-band different from the J target sub-bands, N and J are integers greater than 0 and J is less than N; and determine reverb gain parameters corresponding to the J target sub-bands as target reverb gain parameters.

[00257] Optionally, in one embodiment, the energy of the reduced signal is determined based on the energy of the first signal of Petition 870250032735, dated 04 / 24 / 2025, page 80 / 120 72 / 77 channel and in the energy of the second channel signal.

[00258] Figure 16 is a schematic block diagram of a decoder according to an embodiment of this application. A 1600 decoder in Figure 16 includes: A memory 1610, configured to store a program; and a processor 1620, configured to execute the program, and when the program is executed, the processor 1620 is configured to: receive a bitstream; obtain a reduced signal of a first channel signal and a second channel signal into a multichannel signal and parameter indication information based on the bitstream, where the parameter indication information is used to indicate a target reverberation gain parameter encoded in the reverberation gain parameters corresponding to different sub-bands of the first channel signal and the second channel signal; obtain the target reverberation gain parameter from the bitstream according to the parameter indication information; and determine the first channel signal and the second channel signal based on the reduced signal and the target reverberation gain parameter.

[00259] In this application, the target reverb gain parameter encoded by an encoder can be determined using the parameter indication information, and then reverb processing is performed on a corresponding sub-band of the first channel signal and second channel signal based on the target reverb gain parameter.

[00260] the 1600 decoder can be matched to the multichannel signal decoding method in Figure 4, and the 1600 decoder can perform the multichannel signal decoding method in Figure 4.

[00261] Figure 17 is a schematic block diagram of an encoder according to an embodiment of this application. An encoder 1700 in Figure 17 includes: a 1710 memory, configured to store a program; and Petition 870250032735, dated 04 / 24 / 2025, page 81 / 120 73 / 77 a 1720 processor, configured to execute the program, and when the program is executed, the 1720 processor is configured to: determine a reduced signal of a first channel signal and a second channel signal into a multichannel signal and corresponding reverb gain parameters for different subbands of the first channel signal and the second channel signal; determine, based on the energy of N sub-bands of the reduced signal, a target reverb gain parameter that needs to be encoded into the reverb gain parameters corresponding to the different subbands of the first channel signal and the second channel signal, where N is an integer greater than 0; and encode the reduced signal and the target reverb gain parameter.

[00262] In this request, a specific number of sub-bands are selected directly from all sub-bands based on the energy of each sub-band of the reduced signal, so that a reverb gain parameter that needs to be encoded can be selected with more flexibility.

[00263] The 1700 encoder can match the multichannel signal encoding method in Figure 7, and the 1700 encoder can perform the multichannel signal encoding method in Figure 7.

[00264] Optionally, in one embodiment, the 1720 processor is specifically configured to: determine J target sub-bands from the N sub-bands based on the energy of the N sub-bands, where the energy of any sub-band in the J target sub-bands is greater than the energy of another sub-band different from the J target sub-bands, N and J are integers greater than 0 and J is less than N; and determine reverb gain parameters corresponding to the J target sub-bands as target reverb gain parameters.

[00265] Figure 18 is a schematic block diagram of a decoder according to an embodiment of this application. One Petition 870250032735, dated 04 / 24 / 2025, page 82 / 120 The 74 / 77 1800 decoder in Figure 18 includes: A memory 1810, configured to store a program; and a processor 1820, configured to execute the program, and when the program is executed, the processor 1820 is configured to: receive a bitstream; determine a reduced signal of a first channel signal and a second channel signal into a multichannel signal based on the bitstream; determine, based on the energy of N sub-bands of the reduced signal, a target reverberation gain parameter encoded in the reverberation gain parameters corresponding to different sub-bands of the first channel signal and the second channel signal, where N is an integer greater than 0; determine the target reverberation gain parameter based on the bitstream; and determine the first channel signal and the second channel signal based on the reduced signal and the target reverberation gain parameter.

[00266] In this application, one side of the decoder can directly determine, based on the energy of a plurality of sub-bands of the reduced signal, the target reverberation gain parameter encoded in the reverberation gain parameters corresponding to the different sub-bands of the first channel signal and the second channel signal, so that the bits occupied by the decoder side to transmit indication information to indicate the encoded target reverberation gain parameter are reduced, and the signaling overheads can be reduced to a certain extent.

[00267] The 1800 decoder can be matched to the multichannel signal decoding method in Figure 8, and the 1800 decoder can perform the multichannel signal decoding method in Figure 8.

[00268] Optionally, in one embodiment, the 1820 processor is specifically configured to: determine J target sub-bands from the N sub-bands based on the energy of the N sub-bands, where the energy of any sub-band in the J target sub-bands is greater than Petition 870250032735, dated 04 / 24 / 2025, page 83 / 120 75 / 77 the energy of another sub-band different from the J target sub-bands, N and J are integers greater than 0 and J is less than N; and determine reverberation gain parameters corresponding to the J target sub-bands as target reverberation gain parameters.

[00269] One skilled in the art may be aware that, in combination with the examples described in the embodiments disclosed in this report, algorithm units and steps 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. One skilled in the art may use different methods to implement the described functions for each particular application, but it should not be considered that the implementation goes beyond the scope of this application.

[00270] It may be clearly understood by one skilled in the art that, for the purpose of convenient and brief description, for a detailed working process of the preceding system, apparatus and unit, reference may be made to a corresponding process in the preceding method embodiments, and details are not described here again.

[00271] 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 merely an example. For example, 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 ignored or not implemented. Furthermore, the mutual couplings shown or discussed, direct couplings, or communication connections may be implemented using some interfaces. Petition 870250032735, dated 04 / 24 / 2025, page 84 / 120 76 / 77 Indirect couplings or communication links between devices or units can be implemented in electronic, mechanical, or other forms.

[00272] 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 modal solutions.

[00273] In addition, the functional units in the modalities of this application 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.

[00274] When functions are implemented in the form of a functional software unit and sold or used as a standalone 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 that contributes 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.Previous storage media included: any medium that stores program code, such as a USB drive, a removable hard disk, read-only memory (ROM), random access memory (RAM), a magnetic disk, or an optical disc.

[00275] The preceding descriptions are merely Petition 870250032735, dated 04 / 24 / 2025, page 85 / 120 77 / 77 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 one 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 870250032735, dated 04 / 24 / 2025, page 86 / 120

Claims

1 / 4 CLAIMS 1. Multichannel signal encoding method, characterized in that it comprises: determining (310) a reduced signal of a first channel signal and a second channel signal into a multichannel signal, and reverberation gain parameters corresponding to different sub-bands of the first channel signal and the second channel signal; determining (320) a target reverberation gain parameter that needs to be encoded into the reverberation gain parameters corresponding to different sub-bands of the first channel signal and the second channel signal; generating (330) parameter indication information, wherein the parameter indication information is used to indicate a sub-band corresponding to the target reverberation gain parameter; and encoding (340) the target reverberation gain parameter, the parameter indication information and the reduced signal to generate a bitstream;wherein determining a target reverberation gain parameter that needs to be encoded in the reverberation gain parameters corresponding to the different subbands of the first channel signal and the second channel signal comprises: determining the target reverberation gain parameter based on at least one coherence between the energy of the first channel signal and the energy of the reduced signal and coherence between the energy of the second channel signal and the energy of the reduced signal; wherein each of the first channel signal and the second channel signal comprises a plurality of frequency cages;and determine the target reverberation gain parameter based on at least one coherence between the energy of the first channel signal and the energy of the reduced signal and coherence between Petition 870250032735, dated 04 / 24 / 2025, page 87 / 120 2 / 4 the energy of the second channel signal and the energy of the reduced signal comprises: determining a second difference value between the energy of the second channel signal and the energy of the reduced signal, wherein the second difference value is used to indicate a sum of absolute values ​​of difference values ​​between the energy of the second channel signal and the energy of the reduced signal in the frequency plurality;and when the second difference value is greater than a second threshold, determine that a reverberation gain parameter corresponding to a sub-band of a first frequency band is the target reverberation gain parameter, where the first frequency band is a part of all frequency bands of each of the first channel signal and the second channel signal.

2. A method according to claim 1, characterized in that a frequency in the first frequency band is lower than a frequency in another frequency band different from the first frequency band in the first channel signal and in the second channel signal.

3. A method according to claim 1 or 2, characterized in that the plurality of frequency boxes is in a second frequency band of each of the first channel signal and the second channel signal, and a frequency of the second frequency band is higher than a frequency of another frequency band, different from the second frequency band, in the first channel signal and the second channel signal.

4. Encoder (1100), characterized in that it comprises: a processing unit (1110), configured to determine a reduced signal of a first channel signal and a second channel signal into a multichannel signal, and reverberation gain parameters corresponding to different sub-bands of the first channel signal and the second channel signal, wherein the processing unit (1110) is further configured to determine a target reverberation gain parameter that needs to be encoded into the reverberation gain parameters corresponding to the different sub-bands of the first channel signal and the second channel signal; and the processing unit (1110) is further configured to generate parameter indication information, wherein the parameter indication information is used to indicate a sub-band corresponding to the target reverberation gain parameter;and an encoding unit (1120), configured to encode the target reverberation gain parameter, the parameter indication information and the reduced signal to generate a bitstream; wherein the processing unit is specifically configured to: determine the target reverberation gain parameter based on at least one coherence between the energy of the first channel signal and the energy of the reduced signal and coherence between the energy of the second channel signal and the energy of the reduced signal;wherein each of the first channel signal and the second channel signal comprises a plurality of frequency boxes, and the processing unit is specifically configured to determine a second difference value between the energy of the second channel signal and the energy of the reduced signal, wherein the second difference value is used to indicate a sum of absolute values ​​of difference values ​​between the energy of the second channel signal and the energy of the reduced signal in the plurality of frequency boxes; and when the second difference value is greater than a second threshold, determine that a reverberation gain parameter corresponding to a sub-band of a first frequency band is the target reverberation gain parameter, wherein the first frequency band is a part of all frequency bands of each of the first channel signal and the second channel signal.

5. Encoder, according to claim 4, characterized in that a frequency of the first frequency band is lower than the frequency of another frequency band different from the first frequency band in the first channel signal and in the second channel signal.

6. Encoder, according to claim 4 or 5, characterized in that the plurality of frequency boxes is in a second frequency band of each of the first channel signal and second channel signal, and a frequency of the second frequency band is higher than a frequency of another frequency band, different from the second frequency band, in the first channel signal and in the second channel signal. Petition 870250032735, dated 04 / 24 / 2025, pp. 90 / 120

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