Method and apparatus for reducing context models for entropy coding of transform coefficient valid flag

摘要

A video decoding method performed in a video decoder includes receiving a coded video bitstream including a current picture and at least one syntax element corresponding to transform coefficients of a transform block within the current picture. The method further includes determining an offset value based on the output of the monotonic non-reducing f(x) function performed on the sum (x) of the group of partially reconstructed transform coefficients. The method further includes determining the context model index based on the determined sum of the offset value and the base value. The method further includes, for at least one syntax of a current transform coefficient, selecting a context model from the plurality of context models based on the determined context model index.