Luma mapping with chroma scaling adaptation parameter set in video coding
A video coding mechanism is disclosed. The mechanism includes receiving a bitstream comprising a slice and a luma mapping with chroma scaling (LMCS) adaptation parameter set (APS) including LMCS parameters. The mechanism further includes determining that the LMCS APS is referenced in data related to the slice. The mechanism further includes decoding the slice using LMCS parameters from the LMCS APS based on the reference to the LMCS APS. The mechanism further includes forwarding the slice for display as part of a decoded video sequence.
1. A method implemented by a decoder, the method comprising:
receiving a bitstream comprising a luma mapping with chroma scaling (LMCS) adaptation parameter set (APS) including LMCS parameters associated with a coded slice;
obtaining LMCS parameters from the LMCS APS associated with the coded slice; and
decoding the coded slice using the LMCS parameters from the LMCS APS,
wherein the bitstream further comprises an adaptive loop filter (ALF) APS containing ALF parameters,
wherein each APS includes an APS identifier (ID) selected from a predefined range,
wherein the predefined range is determined based on a parameter type of each APS, and
wherein APSs of a particular type share the same value space for the APS IDs and different types of APSs use different value spaces of the APS IDs.
2. The method of claim 1 , wherein the bitstream further comprises a header related to the coded slice, and wherein the data related to the coded slice contains an APS ID in the header.
3. The method of claim 1 , wherein the bitstream further comprises a scaling list APS containing scaling list parameters, and wherein the scaling list parameters are included in a scaling list for a transform process.
4. The method of claim 3 , wherein each APS includes an APS parameter type (aps_params_type) set to a predefined value indicating a type of parameters included in each APS.
5. The method of claim 3 , wherein each APS is identified by a combination of a parameter type and an APS ID.
6. The method of claim 1 , wherein the bitstream further comprises a sequence parameter set (SPS) including a flag set to indicate LMCS is enabled for an encoded video sequence including the coded slice, and wherein the LMCS parameters from the LMCS APS are obtained based on the flag.
7. A method implemented by an encoder, the method comprising:
determining luma mapping with chroma scaling (LMCS) parameters for a slice;
encoding the slice into a bitstream as a coded slice;
encoding the LMCS parameters into a LMCS adaptation parameter set (APS) of the bitstream; and
encoding into the bitstream data related to the coded slice that references the LMCS APS,
wherein the bitstream further comprises an adaptive loop filter (ALF) APS containing ALF parameters,
wherein each APS includes an APS identifier (ID) selected from a predefined range, wherein the predefined range is determined based on a parameter type of each APS, and
wherein APSs of a particular type share the same value space for the APS IDs and different types of APSs use different value spaces of the APS IDs.
8. The method of claim 7 , wherein the data related to the coded slice MCS contains an APS ID in a header related to the coded slice.
9. The method of claim 7 , wherein the bitstream further comprises a scaling list APS containing scaling list parameters, and wherein the scaling list parameters are included in a scaling list for a transform process.
10. The method of claim 9 , wherein each APS includes an APS parameter type (aps_params_type) code set to a predefined value indicating a type of parameters included in each APS.
11. The method of claim 9 , wherein each APS is identified by a combination of a parameter type and an APS identifier (ID).
12. The method of claim 7 , further comprising encoding a sequence parameter set (SPS) into the bitstream, wherein the SPS includes a flag set to indicate LMCS is enabled for an encoded video sequence including the coded slice.
13. A video coding device comprising:
a receiver configured to receive a bitstream comprising a luma mapping with chroma scaling (LMCS) adaptation parameter set (APS) including LMCS parameters associated with a coded slice; and
a processor coupled to the receiver and configured to:
obtain LMCS parameters from the LMCS APS associated with the coded slice; and
decode the coded slice using the LMCS parameters from the LMCS APS,
wherein the bitstream further comprises an adaptive loop filter (ALF) APS containing ALF parameters,
wherein each APS includes an APS identifier (ID) selected from a predefined range,
wherein the predefined range is determined based on a parameter type of each APS, and
wherein APSs of a particular type share the same value space for the APS IDs and different types of APSs use different value spaces of the APS IDs.
14. The video coding device of claim 13 , wherein the bitstream further comprises a scaling list APS containing scaling list parameters, and wherein the scaling list parameters are included in a scaling list for a transform process.
15. The video coding device of claim 14 , wherein each APS includes an APS parameter type (aps_params_type) set to a predefined value indicating a type of parameters included in each APS.
16. The video coding device of claim 14 , wherein each APS is identified by a combination of a parameter type and an APS ID.
17. The video coding device of claim 13 , wherein the bitstream further comprises a sequence parameter set (SPS) including a flag set to indicate LMCS is enabled for an encoded video sequence including the coded slice, and wherein the LMCS parameters from the LMCS APS are obtained based on the flag.