Methods of palette mode coding in video coding

An apparatus for coding a current palette for a current block in a picture using a palette predictor list, comprising one or more electronic circuits configured to:

• receive input data associated with the current block in the picture;
• determine the current palette for the current block in the picture;
• receive the palette predictor list for the current palette;
• for a current position in the palette predictor list that corresponds to a current predictor entry of the palette predictor list reused by the current palette, determine a current palette predictor run that indicates a distance between the current position in the palette predictor list and a next position that corresponds to a next predictor entry of the palette predictor list reused by the current palette, no predictor entry at a position in the palette predictor list between the current position and the next position being reused by the current palette;
• constrain a syntax element value representing the current palette predictor run to a range of values to cause the next position to be within the palette predictor list;
• and
• signal or parse the syntax element in a bitstream for the current block.

A non-transitory computer readable storage medium storing instructions, which, when being executed by processing circuitry of a device, cause the processing circuitry to perform a method comprising:

• receiving input data associated with a current block in a picture;
• determining a current palette for the current block in the picture;
• receiving a palette predictor list for the current palette;
• for a current position in the palette predictor list that corresponds to a current predictor entry of the palette predictor list reused by the current palette, determining a current palette predictor run that indicates a distance between the current position in the palette predictor list and a next position that corresponds to a next predictor entry of the palette predictor list reused by the current palette, no predictor entry at a position in the palette predictor list between the current position and the next position being reused by the current palette;
• constraining a syntax element Value representing the current palette predictor run to a range of values to cause the next position to be within the palette predictor list;
• and
• signaling or parsing the syntax element in a bitstream for the current block.