Patent ID: 11968398
Assignee: LG ELECTRONICS INC.
Field: Audio-visual technology (Electrical engineering)
Classification: CPC H | IPC H

Claim 1:
2. An encoder for a video encoding, the encoder comprising:
a memory; and
at least one processor connected to the memory, the at least one processor configured to:
perform a primary transform on a transform block;
derive a secondary transform matrix to be applied to the transform block, wherein the secondary transform matrix is used for a secondary transform outputting L (L<N) coefficients (L×1 vector) based on inputted N coefficients (N×1 vector);
perform the secondary transform on the transform block based on the secondary transform matrix;
obtain transform coefficients based on the secondary transform;
derive quantized transform coefficients by performing a quantization on the transform coefficients and encode information related to the quantized transform coefficients; and
generate a secondary transform index corresponding to the secondary transform matrix,
wherein zero transform coefficients are at specific transform coefficient locations, and
wherein the specific transform coefficient locations are arranged in a diagonal scan order from a (L+1)th location to a 16th location in the transform coefficients of the block to which the secondary transform is applied, the block being a 4×4 block, N being 16, and L being 8.