JVET-AP0056 AHG9: Bug fixes for the FGRC SEI message [Y.-K. Wang, J. Xu, K. Zhang (Bytedance)]

This contribution reports some asserted bugs for the film grain regions characteristics (FGRC) SEI message in JVET-AO2032-v2 and proposes changes for fixing those asserted bugs.

Below is a summary of the asserted bugs:

1. Use of fgr_comp_model_present_flag[ ][ ] in a syntax condition
2. Use of fgr_comp_model_value[ ][ ][ ][ ] in Equations 28, 30, and 33 and in NOTE 8
3. Use of fgr_num_intensity_intervals_minus1[ ][ ] in a value range specification
4. Use of fgr_num_intensity_intervals_minus1[ ][ ] for deriving intensityIntervalMax[ c ][ x ][ y ]
5. On a superfluous square bracket in Equation 27
6. On the regional film grain synthesis operation

Further discussion requested.

Further discussed at 1700 on Wednesday 29 Apri 2026 chaired by J. Boyce.

The group agreed on items 1, 2, 3, 4, 5, item 6 (exact wording delegated to editors.)

JVET-AP0056 AHG9: Bug fixes for the FGRC SEI message