Methods and Apparatuses for Coding Video Data with Adaptive Secondary Transform Signaling

• Main Authors: CHUANG, Tzu-Der, CHEN, Ching-Yeh, HSU, Chih-Wei, CHIANG, Man-Shu
• Format: Patent
• Language: English
• Published: 14.07.2022
• Subjects: ELECTRIC COMMUNICATION TECHNIQUE; ELECTRICITY; PICTORIAL COMMUNICATION, e.g. TELEVISION

Video processing methods and apparatuses implemented in a video encoding or decoding system with conditional secondary transform signaling. The video encoding system determines and applies a transform operation to residuals of one or more transform blocks to generate final transform coefficients, and skip signaling a secondary transform index if a position of a last significant coefficient in each considered transform block is less than or equal to a predefined position; otherwise, the video encoding system signals a secondary transform index according to the transform operation. The video decoding system parses last significant coefficient position syntax of each considered transform block to determine a position of a last significant coefficient, and infers inverse secondary transform is not applied if the positions of the last significant coefficients are less than or equal to the predefined position; otherwise, the video decoding system determines an inverse transform operation by parsing a secondary transform index.