Method and apparatus for determining a context model for transform coefficient level entropy encoding and decoding

A method of determining a context model for entropy decoding, the method comprising:

• determining a current transform unit based on size information of a transform unit, wherein the size information is obtained from a bitstream;
• when the current transform unit is a transform unit of a chroma component, determining a context set of a current sub-block in the current transform unit independently of a position of the current sub-block;
• when the current transform unit is a transform unit of a luminance component, determining the context set of the current sub-block in the current transform unit based on the position of current sub-block;
• determining a context model for obtaining first threshold value information based on the context set of the current sub-block;
• and
• determining a context model for obtaining second threshold value information based on the context set of the current sub-block,
• wherein the first threshold value information indicates whether a current transformation coefficient in the current sub-block is greater than a first threshold value, and the second threshold value information indicates whether a current transformation coefficient in the current sub-block is greater than a second threshold value.