Patent ID: 11962770
Assignee: BEIJING DAJIA INTERNET INFORMATION TECHNOLOGY CO., LTD.
Field: Audio-visual technology (Electrical engineering)
Classification: CPC H | IPC H

Claim 0:
1. An intra sub-partition (ISP) method of decoding a video signal, the method comprising:
partitioning a block of video data into a plurality of sub-partitions, wherein each sub-partition comprises N×M samples, where N and M are number of samples in horizontal or vertical direction;
obtaining a number of most probable intra predictions based on intra prediction modes of neighboring blocks of a current block and determining an intra prediction mode to predict the samples of the block sub-partitions;
selecting an optimal transform combination from discrete cosine transform II (DCT-II), discrete sine transform VII (DST-VII), and discrete cosine transform VIII (DCT-VIII) transform kernels for each sub-partition, wherein selecting the optimal transform combination comprises applying a multiple transform selection (MTS) mode to the ISP, wherein the optimal transform combination is indicated by one MTS flag and one MTS index;
obtaining residual coefficients of a first sub-partition and deriving dequantized residual coefficients of the first sub-partition by performing inverse-quantization of the residual coefficients of the first sub-partition;
deriving residual samples of the first sub-partition by performing inverse transforms on dequantized residual coefficients of the first sub-partition in horizontal and vertical directions, wherein the inverse transforms are based on the optimal transform combination of the first sub-partition;
deriving prediction samples of the first sub-partition by performing intra prediction of the first sub-partition based on reconstructed samples adjacent to the first sub-partition;
deriving the reconstructed samples of the first sub-partition by adding the residual samples of the first sub-partition to the prediction samples of the first sub-partition; and
deriving prediction samples of a second sub-partition by performing intra prediction of the second sub-partition based on the reconstructed samples of the first sub-partition,
wherein applying the MTS mode to the ISP comprises:
selecting horizontal and vertical transforms by receiving one MTS flag for the block and one MTS index for each sub-partition, wherein the MTS flag is shared by sub-partitions.