Multi-Channel Signal Encoding Method, Multi-Channel Signal Decoding Method, Encoder, and Decoder

An encoder, comprising:

• one or more memories configured to store programming instructions;
• and
• at least one processor coupled to the one or more memories and configured to execute the programming instructions to cause the encoder to:
• obtain a downmixed signal of a first channel signal in a multi-channel signal and a second channel signal in the multi-channel signal;
• obtain first reverberation gain parameters that correspond to different subbands of the first channel signal and the second channel signal, wherein the first reverberation gain parameters belong to at least two reverberation gain parameter groups;
• select, from the at least two reverberation gain parameter groups, a target reverberation gain parameter group;
• generate parameter indication information that indicates the target reverberation gain parameter group;
• and
• encode second reverberation gain parameters that correspond to the target reverberation gain parameter group, the parameter indication information, and the downmixed signal to obtain a bitstream.

A computer program product comprising computer-executable instructions that are stored on a non-transitory computer-readable medium and that, when executed by a processor, cause an encoder to:

• obtain a downmixed signal of a first channel signal in a multi-channel signal and a second channel signal in the multi-channel signal;
• obtain first reverberation gain parameters that correspond to different subbands of the first channel signal and the second channel signal, wherein the first reverberation gain parameters belong to at least two reverberation gain parameter groups;
• select, from the at least two reverberation gain parameter groups, a target reverberation gain parameter group;
• generate parameter indication information that indicates the target reverberation gain parameter group;
• and
• encode second reverberation gain parameters that correspond to the target reverberation gain parameter group, the parameter indication information, and the downmixed signal to obtain a bitstream.