US-20260129213-A1 - THREE-DIMENSIONAL MESH INTER-FRAME PREDICTION ENCODING METHOD, DECODING METHOD, AND APPARATUS, AND ELECTRONIC DEVICE

Abstract

This application discloses a encoding method performed by an encoder side, including: performing first processing on a to-be-encoded three-dimensional mesh, to obtain a basemesh; performing submesh division on the basemesh, to obtain a P submesh; determining a target encoding mode of a to-be-encoded mesh vertex in the P submesh and a first target motion vector prediction MVP value, where the first target MVP value is one of N MVP values included in a first candidate list, each MVP value in the first candidate list corresponds to one index, and N is an integer greater than 1; and encoding the target encoding mode and an index corresponding to the first target MVP value, to obtain a bitstream including first information, where the first information is used to indicate the target encoding mode and the index corresponding to the first target MVP value.

Inventors

• Wenjie ZOU
• Wei Zhang
• Fuzheng Yang
• Zhuoyi Lv

Assignees

• VIVO MOBILE COMMUNICATION CO., LTD.

Dates

Publication Date

20260507

Application Date

20251230

Priority Date

20230630

Claims (20)

1. 1 . A three-dimensional mesh inter-frame prediction encoding method, comprising: performing, by an encoder side, first processing on a to-be-encoded three-dimensional mesh, to obtain a basemesh; performing, by the encoder side, submesh division on the basemesh, to obtain a P submesh; determining, by the encoder side, a target encoding mode of a to-be-encoded mesh vertex in the P submesh and a first target motion vector prediction (MVP) value, wherein the first target MVP value is one of N MVP values comprised in a first candidate list, each MVP value in the first candidate list corresponds to one index, and N is an integer greater than 1; and encoding, by the encoder side, the target encoding mode and an index corresponding to the first target MVP value, to obtain a bitstream comprising first information, wherein the first information is used to indicate the target encoding mode and the index corresponding to the first target MVP value.
2. 2 . The method according to claim 1 , wherein before the determining, by the encoder side, a target encoding mode of a to-be-encoded mesh vertex in the P submesh and a first target MVP value, the method further comprises: constructing, by the encoder side, the first candidate list based on a neighboring encoded mesh vertex of the to-be-encoded mesh vertex in the P submesh.
3. 3 . The method according to claim 2 , wherein the constructing, by the encoder side, the first candidate list based on a neighboring encoded mesh vertex of the to-be-encoded mesh vertex in the P submesh comprises: obtaining, by the encoder side, L neighboring encoded mesh vertexes and M neighboring encoded mesh vertexes of the to-be-encoded mesh vertex in the P submesh, wherein L and M are integers greater than 1; obtaining, by the encoder side, a motion vector (MV) value of each of the L neighboring encoded mesh vertexes, and determining L first MVP values of a to-be-encoded mesh vertex based on the MV values of the L encoded mesh vertexes; determining, by the encoder side, a second MVP value based on MV values respectively corresponding to the M encoded mesh vertexes; and constructing, by the encoder side, the first candidate list based on the L first MVP values and the second MVP value, wherein L+1≤N.
4. 4 . The method according to claim 3 , wherein the determining, by the encoder side, a second MVP value based on MV values respectively corresponding to the M encoded mesh vertexes comprises: obtaining, by the encoder side, the MV values respectively corresponding to the M encoded mesh vertexes, and determining an average value of the M MV values as the second MVP value; or obtaining, by the encoder side, the MV values respectively corresponding to the M encoded mesh vertexes, performing weighted average calculation on the M MV values, and determining a calculation result as the second MVP value.
5. 5 . An electronic device, comprising a processor and a memory, wherein the memory stores a program or instructions executable on the processor, and when the program or the instructions are executed by the processor, steps of the method according to claim 1 are implemented.
6. 6 . A three-dimensional mesh inter-frame prediction decoding method, comprising: obtaining, by a decoder side, a bitstream sent by an encoder side, wherein the bitstream comprises a basemesh bitstream; decoding, by the decoder side, a basemesh type of the basemesh bitstream, to obtain a P submesh bitstream comprising first information, wherein the first information is used to indicate a target encoding manner and an index corresponding to a first target motion vector prediction (MVP) value; determining, by the decoder side, a target encoding mode according to the first information, and determining the first target MVP value from a first candidate list according to the index corresponding to the first target MVP value, wherein the first candidate list comprises N MVP values and an index corresponding to each MVP value, the first target MVP value is one of the N MVP values, and N is an integer greater than 1; and decoding, by the decoder side, the P submesh bitstream according to the target encoding mode and the first target MVP value, to obtain a motion vector (MV) value of a to-be-decoded mesh vertex in a P submesh.
7. 7 . The method according to claim 6 , wherein before the determining the first target MVP value from a first candidate list according to the index corresponding to the first target MVP value, the method further comprises: constructing, by the decoder side, the first candidate list based on a neighboring decoded mesh vertex of the to-be-decoded mesh vertex in the P submesh.
8. 8 . The method according to claim 7 , wherein the constructing, by the decoder side, the first candidate list based on a neighboring decoded mesh vertex of the to-be-decoded mesh vertex in the P submesh comprises: obtaining, by the decoder side, L neighboring decoded mesh vertexes and M neighboring decoded mesh vertexes of the to-be-decoded mesh vertex in the P submesh, wherein L and M are integers greater than 1; obtaining, by the decoder side, an MV value of each of the L neighboring decoded mesh vertexes, and determining L first MVP values of the to-be-decoded mesh vertex based on the MV values of the L neighboring decoded mesh vertexes; determining, by the decoder side, a second MVP value based on MV values respectively corresponding to the M decoded mesh vertexes; and constructing, by the decoder side, the first candidate list based on the L first MVP values and the second MVP value, wherein L+1≤N.
9. 9 . The method according to claim 8 , wherein the determining, by the decoder side, a second MVP value based on MV values respectively corresponding to the M decoded mesh vertexes comprises: obtaining, by the decoder side, the MV values respectively corresponding to the M decoded mesh vertexes, and determining an average value of the M MV values as the second MVP value; or obtaining, by the decoder side, the MV values respectively corresponding to the M decoded mesh vertexes, performing weighted average calculation on the M MV values, and determining a calculation result as the second MVP value.
10. 10 . The method according to claim 8 , wherein a sorting order of the L first MVP values in the first candidate list is related to first distances, wherein the first distance is a distance between a decoded mesh vertex corresponding to the first MVP value and the to-be-decoded mesh vertex.
11. 11 . The method according to claim 10 , wherein the L first MVP values are sorted in ascending order of the first distances.
12. 12 . The method according to claim 8 , wherein when L+1≤N, the constructing, by the decoder side, the first candidate list based on the L first MVP values and the second MVP value comprises: constructing, by the decoder side, a sub-candidate list based on the L first MVP values and the second MVP value; and performing, by the decoder side, a zero-padding operation on the sub-candidate list, to obtain the first candidate list comprising the N MVP values.
13. 13 . The method according to claim 7 , wherein after the constructing, by the decoder side, the first candidate list based on a neighboring decoded mesh vertex of a to-be-decoded mesh vertex in the P submesh, the method further comprises: resorting, by the decoder side, the N MVP values in the first candidate list, to obtain a resorted first candidate list; and the determining the first target MVP value from a first candidate list according to the index corresponding to the first target MVP value comprises: determining, by the decoder side according to the index corresponding to the first target MVP value, the first target MVP value from the resorted first candidate list.
14. 14 . The method according to claim 13 , wherein the resorting, by the decoder side, the N MVP values in the first candidate list comprises: obtaining, by the decoder side, a sum of errors between a second target MVP value and an MV value of the neighboring decoded mesh vertex of the to-be-decoded mesh vertex, wherein the second target MVP value is one of the N MVP values; and resorting, by the decoder side, the N MVP values based on a sum of errors corresponding to each MVP value in the first candidate list.
15. 15 . The method according to claim 14 , wherein the N MVP values in the resorted first candidate list are sorted in ascending order of the corresponding sum of errors.
16. 16 . The method according to claim 6 , wherein the target encoding mode is a first encoding mode or a second encoding mode, the first encoding mode is a mode in which encoding is directly performed based on the MVP value, and the second encoding mode is a mode in which encoding is performed based on the MVP value and an MVD value.
17. 17 . The method according to claim 16 , wherein when the target encoding mode is the second encoding mode, the P submesh bitstream further comprises the MVD value, and the method further comprises: performing, by the decoder side, MVD decoding on the P submesh bitstream, to obtain an MVD value corresponding to the to-be-decoded mesh vertex in the P submesh; and the obtaining an MV value of a to-be-decoded mesh vertex in a P submesh comprises: determining, according to the MVD value corresponding to the to-be-decoded mesh vertex in the P submesh and the first target MVP value, the MV value corresponding to the to-be-decoded mesh vertex.
18. 18 . An electronic device, comprising a processor and a memory, wherein the memory stores a program or instructions executable on the processor, and when the program or the instructions are executed by the processor, causes the processor to: obtain a bitstream sent by an encoder side, wherein the bitstream comprises a basemesh bitstream; decode a basemesh type of the basemesh bitstream, to obtain a P submesh bitstream comprising first information, wherein the first information is used to indicate a target encoding manner and an index corresponding to a first target motion vector prediction (MVP) value; determine a target encoding mode according to the first information, and determining the first target MVP value from a first candidate list according to the index corresponding to the first target MVP value, wherein the first candidate list comprises N MVP values and an index corresponding to each MVP value, the first target MVP value is one of the N MVP values, and N is an integer greater than 1; and decode the P submesh bitstream according to the target encoding mode and the first target MVP value, to obtain an MV value of a to-be-decoded mesh vertex in a P submesh.
19. 19 . The electronic device according to claim 18 , wherein the processor is further caused to: construct the first candidate list based on a neighboring decoded mesh vertex of the to-be-decoded mesh vertex in the P submesh.
20. 20 . The electronic device according to claim 19 , wherein the processor is further caused to: obtain L neighboring decoded mesh vertexes and M neighboring decoded mesh vertexes of the to-be-decoded mesh vertex in the P submesh, wherein L and M are integers greater than 1; obtain a motion vector (MV) value of each of the L neighboring decoded mesh vertexes, and determining L first MVP values of the to-be-decoded mesh vertex based on the MV values of the L neighboring decoded mesh vertexes; determine a second MVP value based on MV values respectively corresponding to the M decoded mesh vertexes; and construct the first candidate list based on the L first MVP values and the second MVP value, wherein L+1≤N.

Description

CROSS-REFERENCE TO RELATED APPLICATIONS This application is a continuation application of International Application No. PCT/CN2024/100840, filed on Jun. 24, 2024, which claims priority to Chinese Patent Application No. 202310795698.X, filed in China on Jun. 30, 2023, which is incorporated herein by reference in its entirety. TECHNICAL FIELD This application belongs to the field of three-dimensional dynamic mesh encoding and decoding technologies, and specifically, to a three-dimensional mesh inter-frame prediction encoding method, decoding method, and apparatus, and an electronic device. BACKGROUND Over recent years, with the rapid development of multimedia technologies, a three-dimensional model becomes a new generation of digital media following audio, an image, and a video, and a three-dimensional mesh is a common three-dimensional model representation manner. Mesh decimation, mesh parameterization, and subdivision and deformation are performed on the three-dimensional mesh to obtain a basemesh. When the basemesh is encoded, the basemesh is divided into three types, namely, an I submesh, a P submesh, and a skip submesh. For the P submesh, an inter-frame encoding mode is used, and submesh reference information and a motion vector (MV) of each vertex need to be encoded. SUMMARY Embodiments of this application provide a three-dimensional mesh inter-frame prediction encoding method, decoding method, and apparatus, and an electronic device. According to a first aspect, a three-dimensional mesh inter-frame prediction encoding method is provided, performed by an encoder side, and including: performing, by the encoder side, first processing on a to-be-encoded three-dimensional mesh, to obtain a basemesh;performing, by the encoder side, submesh division on the basemesh, to obtain a P submesh;determining, by the encoder side, a target encoding mode of a to-be-encoded mesh vertex in the P submesh and a first target motion vector prediction (MVP) value, where the first target MVP value is one of N MVP values included in a first candidate list, each MVP value in the first candidate list corresponds to one index, and N is an integer greater than 1; andencoding, by the encoder side, the target encoding mode and an index corresponding to the first target MVP value, to obtain a bitstream including first information, where the first information is used to indicate the target encoding mode and the index corresponding to the first target MVP value. According to a second aspect, a three-dimensional mesh inter-frame prediction decoding method is provided, performed by a decoder side, and including: obtaining, by the decoder side, a bitstream sent by an encoder side, where the bitstream includes a basemesh bitstream;decoding, by the decoder side, a basemesh type of the basemesh bitstream, to obtain a P submesh bitstream including first information, where the first information is used to indicate a target encoding manner and an index corresponding to a first target MVP value;determining, by the decoder side, a target encoding mode according to the first information, and determining the first target MVP value from a first candidate list according to the index corresponding to the first target MVP value, where the first candidate list includes N MVP values and an index corresponding to each MVP value, the first target MVP value is one of the N MVP values, and N is an integer greater than 1; anddecoding, by the decoder side, the P submesh bitstream according to the target encoding mode and the first target MVP value, to obtain an MV value of a to-be-decoded mesh vertex in a P submesh. According to a third aspect, a three-dimensional mesh inter-frame prediction encoding apparatus is provided, including: a processing module, configured to perform first processing on a to-be-encoded three-dimensional mesh, to obtain a basemesh;a division module, configured to perform submesh division on the basemesh, to obtain a P submesh;a first determining module, configured to determine a target encoding mode of a to-be-encoded mesh vertex in the P submesh and a first target motion vector prediction MVP value, where the first target MVP value is one of N MVP values included in a first candidate list, each MVP value in the first candidate list corresponds to one index, and N is an integer greater than 1; andan encoding module, configured to encode the target encoding mode and an index corresponding to the first target MVP value, to obtain a bitstream including first information, where the first information is used to indicate the target encoding mode and the index corresponding to the first target MVP value. According to a fourth aspect, a three-dimensional mesh inter-frame prediction decoding apparatus is provided, including: an obtaining module, configured to obtain a bitstream sent by an encoder side, where the bitstream includes a basemesh bitstream;a first decoding module, configured to decode a basemesh type of the basemesh bitstream, to obta