METHOD, COMPUTER PROGRAM PRODUCT AND DEVICE FOR DECODING CBF FLAGS

A method of coding implemented by a decoding device or encoding device, the method comprising obtaining a bitstream, the bitstream comprises a transform unit syntax, (in an example, the transform unit syntax element can be either coded for a whole block or coded for multiple sub-transform units that are obtained by Sub-Block Transform for inter block (SBT), or in order to satisfy maximal transform unit size restrictions); the syntax comprises at least two cbf flags for chroma blocks (in an example, transform unit syntax correspond to either transform unit or sub-transform units which include two chroma cbf flags: tu_cbf_cb and tu_cbf_cb - one flag for each chroma plane), a chroma cbf flag specifies whether certain block has residue in correspondent color plane; deriving a value of a luma cbf flag tu_cbf_luma based on one or any combination of a value of a cu_cbf flag, values of two chroma cbf flags corresponding to a current transform unit or sub-transform unit, location of the sub-transform unit within transform unit, values of luma and chroma cbf flags correspondent to previous sub-transform units in the current transform unit.