QUALCOMM Incorporated
Low-frequency non-separable transform signaling based on zero-out patterns for video coding

Abstract:

A video decoder is configured to determine a position of a last significant coefficient in a transform block of video data. The video decoder may then determine a value of a low-frequency non-separable transform (LFNST) index for the transform block based on the position of the last significant coefficient relative to a zero-out region of the transform block, wherein the zero-out region of the transform block includes both a first region within an LFNST region of the transform block and a second region of the transform block outside the LFNST region. The video decoder may then inverse transform the transform block in accordance with the value of the LFNST index.