Methods and systems for signaling and performing secondary transforms

Abstract

Methods and systems for encoding and decoding video are described. In one aspect, a method of video decoding includes receiving video data that includes a first block and a first syntax element from a video bitstream. The method also includes determining a secondary transform kernel type value for the first block based on the first syntax element. In accordance with a determination that the secondary transform kernel type has a first value, a secondary transform set identifier is determined based on a second syntax element from the video bitstream, and an inverse secondary transform is performed on the first block using the determined secondary transform kernel type and determined secondary transform set identifier. In accordance with a determination that the secondary transform kernel type has a second value, the inverse secondary transform is not performed on the first block.