JPWO2020060867A5

JPWO2020060867A5 -

Info

Publication number: JPWO2020060867A5
Application number: JP2021506651A
Authority: JP
Publication date: 2022-09-27

Claims

a method,
Entropy decoding a first set of parameters associated with a first transform coefficient in a block of a picture, wherein the first transform coefficient is, in decoding order, a second transform coefficient in the block of the picture. precedes the
entropy decoding a second parameter set associated with the second transform coefficients, wherein the first and second parameter sets are entropy encoded in a normal mode; Contextual modeling of at least parameters in a second parameter set depends on decoding the first transform coefficients, the first and second parameter sets are entropy decoded in a first scan pass of the block, and the A first scan pass is performed before one or more other scan passes on entropy-decoded transform coefficients of the block, the first and second parameter sets for the first and second transform coefficients. includes at least a first flag and a second flag, the first flag indicating whether the absolute value of the corresponding transform coefficient is greater than one, and the second flag indicating whether the indicating whether the absolute value of the corresponding transform coefficient is greater than 3;
reconstructing the block in response to the decoded transform coefficients;
A method.

2. The method of claim 1, wherein an inverse quantizer that inverse quantizes the second transform coefficients is selected from two or more quantizers based on the first transform coefficients.

3. The method of claim 2, wherein the inverse quantizer is selected based on the first parameter set of the first transform coefficients.

3. The method of claim 2, wherein the inverse quantizer is selected based on the SIG, a sum or an XOR function of first and second flags of the first parameter set.

The inverse quantizer is selected based on the first flag, the second flag, or another flag of the first parameter set, the another flag being the absolute value of the corresponding transform coefficient. 3. The method of claim 2, indicating whether is greater than x.

6. The method of claim 5, wherein context modeling of the SIG, first, second flag, or another flag is based on the state used in the quantizer or selection of the quantizer.

An apparatus comprising one or more processors, the one or more processors comprising:
entropy decoding a first set of parameters associated with a first transform coefficient in a block of a picture, the first transform coefficient preceding a second transform coefficient in the block of the picture in decoding order;
entropy decoding a second parameter set associated with the second transform coefficient, the first and second parameter sets being entropy encoded in a normal mode, the second parameter of the second transform coefficient; Contextual modeling of at least parameters in a set depends on decoding the first transform coefficients, the first and second parameter sets are entropy decoded in a first scan pass of the block, and the first scan pass is performed. A pass is performed before one or more other scan passes for entropy-decoded transform coefficients of said block, wherein each set of said first and second parameter sets for said first and second transform coefficients is , at least a first flag and a second flag, wherein the first flag indicates whether the absolute value of the corresponding transform coefficient is greater than 1, the second flag indicates whether the corresponding transform coefficient indicates whether the absolute value of is greater than 3,
Reconstructing the block in response to the decoded transform coefficients
A device configured to

8. The apparatus of claim 7, wherein an inverse quantizer that inverse quantizes the second transform coefficients is selected from two or more quantizers based on the first transform coefficients.

9. The apparatus of Claim 8, wherein the inverse quantizer is selected based on the first set of parameters for the first transform coefficients.

9. The apparatus of claim 8, wherein the inverse quantizer is selected based on the SIG, a sum or XOR function of first and second flags of the first parameter set.

The inverse quantizer is selected based on the first flag, the second flag, or another flag of the first parameter set, the another flag being the absolute value of the corresponding transform coefficient. 9. The apparatus of claim 8, indicating whether is greater than x.

9. The apparatus of claim 8, wherein context modeling of the SIG, first, second flag or another flag is based on the state used in the quantizer or selection of the quantizer.

a method,
accessing a first set of parameters associated with a first transform coefficient in a block of a picture, wherein the first transform coefficient is in coding order a second transform coefficient in the block of the picture; precedes the
accessing a second parameter set associated with the second transform coefficients, wherein the first and second parameter sets are entropy coded in a normal mode; contextual modeling of at least parameters of two parameter sets depending on the encoding of the first transform coefficients;
entropy coding the first and third parameter sets in a first scan pass of the block, wherein the first scan pass entropy-encodes one or more other of the entropy-coded transform coefficients of the block; wherein each set of said first and second parameter sets for said first and second transform coefficients comprises at least a first flag and a second flag, and said first indicates whether the absolute value of the corresponding transform coefficient is greater than 1, and the second flag indicates whether the absolute value of the corresponding transform coefficient is greater than 3;
A method.

14. The method of claim 13, wherein a quantizer that quantizes the second transform coefficients is selected from two or more quantizers based on the first transform coefficients.

15. The method of claim 14, wherein the quantizer is selected based on the SIG, a sum or an XOR function of first and second flags of the first parameter set.

16. The method of claim 15, wherein context modeling of the SIG, first and second flags is based on the quantizer or states used in selecting the quantizer.

An apparatus comprising one or more processors, the one or more processors comprising:
accessing a first set of parameters associated with a first transform coefficient in a block of a picture, wherein the first transform coefficient precedes a second transform coefficient in the block of the picture in coding order;
accessing a second parameter set associated with the second transform coefficients, wherein the first and second parameter sets are entropy coded in normal mode, the second parameter set of the second transform coefficients; contextual modeling of at least parameters of depends on the encoding of the first transform coefficients;
entropy encoding the first and third parameter sets in a first scan pass of the block, wherein the first scan pass precedes one or more other scan passes of entropy coded transform coefficients of the block; wherein each set of said first and second parameter sets for said first and second transform coefficients comprises at least a first flag and a second flag, wherein said first flag corresponds to indicates whether the absolute value of the corresponding transform coefficient is greater than one, and the second flag indicates whether the absolute value of the corresponding transform coefficient is greater than three.
A device configured to

18. The apparatus of claim 17, wherein a quantizer that quantizes the second transform coefficients is selected from two or more quantizers based on the first transform coefficients.

19. The apparatus of claim 18, wherein the quantizer is selected based on the SIG, a sum or an XOR function of first and second flags of the first parameter set.

19. The apparatus of claim 18, wherein the context modeling of the SIG, first and second flags is based on the quantizer or states used in selecting the quantizer.