Granted Patent B2

US 12,244,806 · App. 17/700,904 · Granted Mar 4, 2025

Inventors: Roman Igorevich Chernyak (Moscow, RU); Sergey Yurievich Ikonin (Moscow, RU); Timofey Mikhailovich Solovyev (Moscow, RU); Alexander Alexandrovich Karabutov (Moscow, RU); Elena Alexandrovna Alshina (Munich, DE)

Assignee: HUAWEI TECHNOLOGIES CO., LTD.

H04N19/124H04N19/176H04N19/186H04N19/70

Abstract

Claims (39)

1. A method for inverse quantization of a current chrominance block of a picture, wherein the method is performed by a decoder, and the method comprising:

receiving a bitstream;

obtaining a value of a joint chrominance component residual (JCCR) control flag from the bitstream, wherein the JCCR control flag specifies whether joint coding of a cb chrominance component and a cr chrominance component is enabled or disabled;

obtaining a chrominance mapping information from the bitstream directly dependent on the value of the JCCR control flag;

obtaining at least one chrominance quantization parameter (QP) offset from the bitstream directly dependent on the value of the JCCR control flag;

obtaining a QP value for the current chrominance block based on the obtained chrominance mapping information and the at least one obtained chrominance QP offset; and

performing inverse quantization on the current chrominance block by using the obtained QP value.

2. The method according to claim 1 , wherein the bitstream comprises a sequence parameter set (SPS) level syntax, and the JCCR control flag is obtained from the SPS level syntax.

3. The method according to claim 1 , wherein the JCCR control flag is the sps_joint_cbcr_enabled_flag.

4. The method according to claim 3 , wherein if a value of the sps_joint_cbcr_enabled_flag is 1, the at least one obtained chrominance QP offset is specified by slice_joint_cbcr_qp_offset.

5. The method according to claim 1 , wherein the chrominance mapping information comprises delta_qp_in_val_minus1 and delta_qp_out_val, and the chrominance mapping information is obtained from an SPS level syntax comprised in the bitstream.

6. The method according to claim 1 , wherein the obtaining the at least one chrominance QP offset from the bitstream based on the JCCR control flag comprises:

obtaining, based on the JCCR control flag, the at least one chrominance QP offset from a picture parameter set (PPS) level syntax of the bitstream.

7. A method for encoding a current block of a picture, wherein the method is performed by an encoder, the method comprising:

encoding a value of a joint chrominance component residual (JCCR) control flag into a bitstream, wherein the JCCR control flag specifies whether joint coding of a cb chrominance component and a cr chrominance component is enabled or disabled;

encoding a chrominance mapping information into the bitstream directly dependent on the value of the JCCR control flag;

encoding at least one chrominance quantization parameter (QP) offset into the bitstream directly dependent on the value of the JCCR control flag;

providing the bitstream.

8. The method according to claim 7 , wherein the bitstream comprises a sequence parameter set (SPS) level syntax, and the JCCR control flag is encoded into the SPS level syntax.

9. The method according to claim 7 , wherein the JCCR control flag is the sps_joint_cbcr_enabled_flag.

10. The method according to claim 9 , wherein if a value of the sps_joint_cbcr_enabled_flag is 1, the at least one encoded chrominance QP offset is specified by slice_joint_cbcr_qp_offset.

11. The method according to claim 7 , wherein the chrominance mapping information comprises delta_qp_in_val_minus1 and delta_qp_out_val, and the chrominance mapping information is encoded into an SPS level syntax comprised in the bitstream.

12. The method according to claim 7 , wherein the encoding the at least one chrominance QP offset into the bitstream based on the JCCR control flag comprises:

encoding, based on the JCCR control flag, the at least one chrominance QP offset into a picture parameter set (PPS) level syntax of the bitstream.

13. A video decoding device, comprising:

a non-transitory memory storage, configured to store video data in a form of a bitstream; and

a video decoder, configured to:

receive the bitstream;

obtain a value of a joint chrominance component residual (JCCR) control flag from the bitstream, wherein the JCCR control flag specifies whether joint coding of a cb chrominance component and a cr chrominance component is enabled or disabled;

obtain a chrominance mapping information from the bitstream directly dependent on the value of the JCCR control flag;

obtain at least one chrominance quantization parameter (QP) offset from the bitstream directly dependent on the value of the JCCR control flag;

obtain a QP value for a current chrominance block based on the obtained chrominance mapping information and the at least one obtained chrominance QP offset; and

performing inverse quantization on the current chrominance block by using the determined QP value.

14. The video decoding device according to claim 13 , wherein the bitstream comprises a sequence parameter set (SPS) level syntax, and the JCCR control flag is obtained from the SPS level syntax.

15. The video decoding device according to claim 13 , wherein the JCCR control flag is the sps_joint_cbcr_enabled_flag.

16. The video decoding device according to claim 15 , wherein if a value of the sps_joint_cbcr_enabled_flag is 1, the at least one obtained chrominance QP offset is specified by slice_joint_cbcr_qp_offset.

17. The video decoding device according to claim 13 , wherein the chrominance mapping information comprises delta_qp_in_val_minus1 and delta_qp_out_val, and the chrominance mapping information is obtained from an SPS level syntax comprised in the bitstream.

18. The video decoding device according to claim 13 , wherein the video decoding device is further configured to:

obtaining, based on the JCCR control flag, the at least one chrominance QP offset from a picture parameter set (PPS) level syntax of the bitstream.

Assignments (1)

Priority Claims (1)

Continuity (2)

References Cited (37)