Coding of transform coefficients in video coding

A computing device comprising:

• one or more processors;
• a non-transitory storage coupled to the one or more processors;
• and
• a plurality of programs stored in the non-transitory storage that, when executed by the one or more processors, cause the computing device to perform acts comprising:
• determining, for a current luma transform block in a coding unit, whether a first variable indicating an intra subpartition (ISP) split type is equal to ISP_NO_SPLIT;
• in response to determining that the first variable is equal to ISP_NO_SPLIT, determining a luma block flag context index for a luma block flag of the current luma transform block as being equal to zero or one without determining whether the current luma transform block is smaller than the coding unit, wherein the luma block flag of the current luma transform block specifies whether the current luma transform block comprises one or more transform coefficient levels not equal to zero;
• and
• in response to determining that the first variable is not equal to ISP_NO_SPLIT, determining the luma block flag context index based on a second variable of a previous luma transform unit in the coding unit.

A non-transitory computer readable storage medium storing a bitstream to be decoded by a method for video coding comprising:

• determining, for a current luma transform block in a coding unit, whether a first variable indicating an intra subpartition (ISP) split type is equal to ISP_NO_SPLIT;
• in response to determining that the first variable is equal to ISP_NO_SPLIT, determining a luma block flag context index for a luma block flag of the current luma transform block as being equal to zero or one without determining whether the current luma transform block is smaller than the coding unit, wherein the luma block flag of the current luma transform block specifies whether the current luma transform block comprises one or more transform coefficient levels not equal to zero;
• and
• in response to determining that the first variable is not equal to ISP_NO_SPLIT, determining the luma block flag context index based on a second variable of a previous luma transform unit in the coding unit.