Method and Apparatus for Entropy Coding of Source Samples with Large Alphabet

A method of entropy decoding for source symbols in a decoder comprising:

• receiving an input coded bitstream including compressed data for a current source symbol;
• decoding the input coded bitstream to recover a first binary string, a second binary string and any third binary string;
• recovering a first prefix part related to a prefix part for a current symbol by decoding the first binary string using a first variable length code if a test value related to the prefix part is greater than or equal to a threshold;
• recovering a second prefix part related to the prefix part for the current symbol by decoding the second binary string using a second variable length code or a first fixed-length code if the test value related to the prefix part is less than the threshold;
• recovering a suffix part for the current symbol by decoding the third binary string using a second fixed-length code or a first truncated binary code if any third binary string exists;
• and
• recovering the current source symbol based on the prefix part and any suffix part of the current symbol if any suffix part exists, wherein the prefix part consists of the first prefix part and the second prefix part.