lmcs enabled flag need to be updated in decoding process

[taoranlu]

Q0346 proposed to add back slice level on/off control of LMCS. The slice header syntax has been added in Q2001-vA but the controls in low level decoding process haven't been updated properly. To be specific:

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In 8.5.6.7: When cIdx is equal to 0 and ph_lmcs_enabled_flag is equal to 1, ...

should be: When cIdx is equal to 0 and slice_lmcs_enabled_flag is equal to 1, ...

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In 8.7.5.1:
Depending on the value of ph_lmcs_enabled_flag, the following applies:
– If ph_lmcs_enabled_flag is equal to 0, ....
– Otherwise (ph_lmcs_enabled_flag is equal to 1),....

should be:
Depending on the value of slice_lmcs_enabled_flag, the following applies:
– If slice_lmcs_enabled_flag is equal to 0, ....
– Otherwise (slice_lmcs_enabled_flag is equal to 1),....

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In 8.7.5.3:
– ph_chroma_residual_scale_flag is equal to 0.

should be
– ph_chroma_residual_scale_flag is equal to 0 or slice_lmcs_enabled_flag is equal to 0.

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In 8.8.2.2: If ph_lmcs_enabled_flag of the slice that ...

should be: If slice_lmcs_enabled_flag of the slice that ...

[yk]

Thanks for the detailed suggestions. Will be fixed in JVET-Q2001-vB.