Encoding method and apparatus, decoding method and apparatus, and device

A decoding method, comprising:

• demultiplexing, by a decoder, an obtained target bitstream to obtain a first bitstream, a second bitstream, and a third bitstream, wherein the first bitstream is obtained based on a basemesh corresponding to a target three-dimensional mesh, the second bitstream is obtained based on mesh difference information, the mesh difference information is used to represent difference information between the basemesh and a to-be-encoded three-dimensional mesh, the target three-dimensional mesh is obtained based on the to-be-encoded three-dimensional mesh, and the third bitstream is obtained based on reconstructed texture map information;
• and
• in a case that the decoder determines that the first bitstream comprises reconstructed texture coordinate information, reconstructing a target three-dimensional mesh based on a first decoding result corresponding to the first bitstream, a second decoding result corresponding to the second bitstream, and a third decoding result corresponding to the third bitstream;
• and/or
• in a case that the decoder determines that the first bitstream does not comprise reconstructed texture coordinate information, generating reconstructed texture coordinate information, and reconstructing a target three-dimensional mesh based on the generated reconstructed texture coordinate information, a first decoding result corresponding to the first bitstream, a second decoding result corresponding to the second bitstream, and a third decoding result corresponding to the third bitstream.

A decoding device, comprising a processor and a memory, wherein the memory stores a program or instructions capable of running on the processor, wherein the program or instructions, when executed by the processor, cause the decoding device to perform:

• demultiplexing an obtained target bitstream to obtain a first bitstream, a second bitstream, and a third bitstream, wherein the first bitstream is obtained based on a basemesh corresponding to a target three-dimensional mesh, the second bitstream is obtained based on mesh difference information, the mesh difference information is used to represent difference information between the basemesh and a to-be-encoded three-dimensional mesh, the target three-dimensional mesh is obtained based on the to-be-encoded three-dimensional mesh, and the third bitstream is obtained based on reconstructed texture map information;
• and
• in a case that the decoding device determines that the first bitstream comprises reconstructed texture coordinate information, reconstructing a target three-dimensional mesh based on a first decoding result corresponding to the first bitstream, a second decoding result corresponding to the second bitstream, and a third decoding result corresponding to the third bitstream;
• and/or
• in a case that the decoding device determines that the first bitstream does not comprise reconstructed texture coordinate information, generating reconstructed texture coordinate information, and reconstructing a target three-dimensional mesh based on the generated reconstructed texture coordinate information, a first decoding result corresponding to the first bitstream, a second decoding result corresponding to the second bitstream, and a third decoding result corresponding to the third bitstream.