Method and apparatus for performing arithmetic coding on basis of concatenated ROM-RAM table
AssigneeLG Electronics Inc.
InventorsAmir Said, Abo Talib Mahfoodh
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Abstract
Disclosed herein is a method of performing an arithmetic decoding for data symbols, comprising: creating a decoding table index; obtaining an upper bound value and a lower bound value of a ratio between an interval length and a point within an interval assigned to a symbol from a ROM table; obtaining initial values for a bisection search from a RAM table based on the upper bound value and the lower bound value; and searching a value of sequence in the interval, wherein the interval is determined based on the initial values.
Claims8
A method of performing an arithmetic decoding for a data symbol that is defined by a ratio (Dk/Lk) between an interval length and a point within an interval assigned to the data symbol, comprising:
- creating, by a processor, a decoding table index by:
- combining, by the processor, a most significant bit of the interval length and a most significant bit of the point within the interval assigned to the data symbol;
- determining, by the processor, a position of a most significant 1 bit of the interval length;
- extracting, by the processor, a most significant bit of the interval length after the most significant 1 bit by starting from the position plus 1 bit;
- and
- extracting, by the processor, a most significant bit of an interval base by starting from the position;
- obtaining, by the processor, an upper bound value (Emax) and a lower bound value (Emin) of the ratio (Dk/Lk) from a decoding table stored in a ROM;
- obtaining, by the processor, initial values for a bisection search from a RAM table based on the upper bound value and the lower bound value;
- and
- decoding, by the processor, the data symbol in the interval,
- wherein the interval is determined based on the initial values.
An apparatus of performing an arithmetic decoding for a data symbol which is defined by a ratio (Dk/Lk) between an interval length and a point within an interval assigned to the data symbol, comprising:
- a processor configured to:
- create a decoding table index by combining a most significant bit of the interval length and a most significant bit of the point within the interval assigned to the data symbol;
- determine a position of a most significant 1 bit of the interval length;
- extract a most significant bit of the interval length after the most significant 1 bit by starting from the position plus 1 bit;
- extract a most significant bit of an interval base by starting from the position;
- obtain an upper bound value and a lower bound value of ratio (Dk/Lk) from a decoding table stored in ROM, and obtain initial values for a bisection search from a decoding table stored in a RAM based on the upper bound value and the lower bound value;
- search a value of sequence in the interval;
- and
- decode the data symbol corresponding to the value of sequence,
- wherein the interval is determined based on the initial values.
Dependencies are inferred from the claim text.