Method of determining binary codewords for transform coefficients

摘要

A system is provided for creating binary codewords for transform coefficients used for relating transform units (TUs) divided into coding units (CUs) in a High Efficiency Video Coding (HEVC) system. The system provides binarization of the codewords and removes unnecessary operations to reduce system complexity and increase compression performance. The system generates transform coefficients that relate the TUs and begins by providing a parameter variable (cRiceParam) set to an initial value of zero. Significant transform coefficients are converted into binary codewords based on the current value of the parameter variable, and the parameter variable is then updated with a new current value after each transform coefficient has been converted. Updating can be provided with reference to table values or the values can be provided from combination logic.

主权项

1. A method of determining binary codewords for transform coefficients, comprising:
providing a transform unit comprising a first subset of transform coefficients and a second subset of transform coefficients, wherein the first and second subsets are non-overlapping, and each transform coefficient of the first and second groups has a quantized value; determining a symbol for each of the transform coefficients of the first subset that have a quantized value equal to or greater than a threshold value by subtracting said threshold value from the absolute value of said transform coefficient wherein said threshold value is three; initially setting a parameter variable to a value of zero; converting each symbol of the first subset into a binary codeword based on the value of said parameter variable; updating said parameter variable after each symbol of the first subset has been converted by setting said parameter variable to a new value, said new value being based at least in part on the value of said parameter variable preceding said updating and the value of the most recently converted symbol of the first subset, wherein the new value of said parameter variable is four; and resetting the parameter variable to the value of zero after a last symbol of the first subset has been converted and before converting a symbol for a first transform coefficient of the second subset, wherein each said binary codeword comprises a Truncated Rice portion having up to a predefined maximum number of bits that is no higher than 8 bits, and the value of each said parameter variable is respectively associated with a maximum symbol value for said symbol.