Adaptive colour transform related signalling for both of CU level and TU level
There is included a method and apparatus comprising computer code configured to cause a processor or processors to perform obtaining video data, obtaining a coding unit (CU) block, determining whether a flag of the CU block is set to a predetermined flag condition, determining whether a tree type of the CU block is set to a predetermined tree type, determining whether to signal an adaptive color transform (ACT) flag based on any of whether the flag of the CU block is set to the predetermined flag condition and whether the tree type of the CU block is set to the predetermined tree type, and coding the video data based on a whether the ACT flag is signaled.
1. A method for video decoding performed by at least one processor, the method comprising:
obtaining video data comprising a coding unit (CU);
determining whether an adaptive color transform (ACT) flag is signaled based on both of values of a flag of the CU and a tree type of the CU; and
decoding the video data based on a whether the ACT flag is signaled, and
wherein the ACT flag comprises a syntax of at least “act_enabled_flag”.
2. The method according to claim 1 , further comprising:
determining whether the flag of the CU is set to a predetermined flag condition; and
determining whether the tree type of the CU is set to a predetermined tree type, and
wherein the ACT flag is further based on whether the flag of the CU is set to the predetermined flag condition and whether the tree type of the CU is set to the predetermined tree type.
3. The method according to claim 2 , wherein the ACT flag is based on whether the flag of the CU is set to the predetermined flag condition.
4. The method according to claim 2 , wherein the predetermined tree type indicates a single tree type, and wherein the predetermined flag condition comprises sps_act_enabled_flag being equal to 1.
5. The method according to claim 1 , wherein the ACT flag is signaled when a prediction mode of the CU is an intra mode.
6. The method according to claim 1 , further comprises determining whether transform unit (TU) coded flags are both zero and whether the CU is coded with an ACT mode.
7. The method according to claim 6 , wherein the TU coded flags are flags of chrominance channels.
8. A method for video encoding performed by at least one processor, the method comprising:
obtaining video data;
determining whether an adaptive color transform (ACT) flag is to be signaled based on both of values of a flag of a coding unit (CU) of the video data and a tree type of the CU; and
encoding the video data based on a whether the ACT flag is to be signaled, and
wherein the ACT flag comprises a syntax of at least “act_enabled_flag”.
9. The method according to claim 8 , further comprising:
determining whether the flag of the CU is to be set to a predetermined flag condition; and
determining whether the tree type of the CU is to be set to a predetermined tree type, and
wherein the ACT flag is further based on whether the flag of the CU is to be set to the predetermined flag condition and whether the tree type of the CU is set to the predetermined tree type.
10. The method according to claim 9 , wherein the ACT flag is based on whether the flag of the CU is to be set to the predetermined flag condition.
11. The method according to claim 9 , wherein the predetermined tree type indicates a single tree type, and wherein the predetermined flag condition comprises sps_act_enabled_flag being equal to 1.
12. The method according to claim 8 , wherein the ACT flag is to be signaled when a prediction mode of the CU is to be an intra mode.
13. The method according to claim 8 , further comprises determining whether transform unit (TU) coded flags are to be both zero and whether the CU is to be coded with an ACT mode.
14. The method according to claim 13 , wherein the TU coded flags are flags of chrominance channels.
15. A method of processing visual media data, comprising:
performing a conversion between a visual media file and a bitstream of a visual media data according to a format rule based on:
determining whether an adaptive color transform (ACT) flag is signaled or is to be signaled based on both of values of a flag of a coding unit (CU) and a tree type of the CU; and
performing the conversion based on a whether the ACT flag is or is to be signaled, and
wherein the ACT flag comprises a syntax of at least “act_enabled_flag”.
16. The method according to claim 15 , the format rule is further based on:
determining whether the flag of the CU is set or is to be set to a predetermined flag condition; and
determining whether the tree type of the CU is set or is to be set to a predetermined tree type, and
wherein the ACT flag is further based on whether the flag of the CU is set or is to be set to the predetermined flag condition and whether the tree type of the CU is set to the predetermined tree type.
17. The method according to claim 16 , wherein the ACT flag is based on whether the flag of the CU is set or is to be set to the predetermined flag condition.
18. The method according to claim 16 , wherein the predetermined tree type indicates a single tree type, and wherein the predetermined flag condition comprises sps_act_enabled_flag being equal to 1.
19. The method according to claim 15 , wherein the ACT flag is signaled when a prediction mode of the CU is an intra mode.
20. The method according to claim 15 , wherein the format rule is further based on determining whether transform unit (TU) coded flags are both zero and whether the CU is coded with an ACT mode.
21. The method according to claim 20 , wherein the TU coded flags are flags of chrominance channels.