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US 7,113,646 B2Granted
Decoding of predicted AC coefficient without division
AssigneeEquator Technologies, Inc.
InventorJeongnam Youn
Life of this patent
Estimating the term…
Abstract
A technique for eliminating the division in decoding a predicted AC coefficient includes calculating and storing the values of I//AC_stepsize in a table. This allows one to convert a division into a multiplication.
Claims13
A processing circuit comprising:
- a storage circuit operable to store a lookup table;
- and
- a processor operable to:
- calculate all possible values for an inverted variable in the equation for decoding predicted non zero frequency transform coefficients;
- and
- store all said values in said lookup table.
3 more elements
A processing circuit comprising:
- a storage circuit operable to store a lookup table of all one hundred and twenty-two possible values for the inverted scalar value of a quantization parameter for a macro block;
- and
- a processor operable to calculate the non-zero-frequency coefficient for a macro block using a said table to avoid using a division rounding results to the nearest integer value.
A processing circuit comprising:
- a storage circuit operable to store a lookup table of all one hundred and twenty-two values of the inverted scalar value of a quantization parameter for a macro block calculated off-line;
- and
- a processor operable to calculate the non-zero-frequency coefficients for any number of macro blocks being decoded without using the divide unit of said processor by repeatedly using said stored look up table.
A processing circuit comprising:
- a storage circuit operable to store a lookup table;
- and
- a processor operable to receive encoded images, each in a standard format, and to decode said received encoded bit stream using said lookup table wherein a divide unit of the processor is not used when decoding predicted non-zero-frequency transform coefficients.
A method comprising:
- generating a lookup table of one hundred and twenty-two values of an inverted scalar value of a quantization parameter for a macro block;
- and
- calculating the non-zero-frequency coefficient for a macro block using said table to avoid using rounding division.
A method comprising:
- storing a lookup table of one hundred and twenty-two values of an inverted scalar value of a quantization parameter for a macro block;
- and
- decoding a received encoded-image bit stream with said lookup table wherein a division operation is not used when decoding predicted non-zero-frequency transform coefficients.
A method comprising:
- receiving encoded images, each in a standard format;
- and
- decoding predicted non-zero-frequency transform coefficients using values from a look-up table and without division.
Dependencies are inferred from the claim text.