JVET-AN0167 AHG9: On localization and mapping SEI message [C. Kim, H. Tan, J. Lee, J. Nam, J. Lim, S. Kim (LGE)]
This contribution proposes miscellaneous modifications that are asserted to provide improvement to some aspects of LAM SEI messages in the TuC for future extensions of VSEI. The proposed modifications are as follows:
- On rotation representation – constraints and decoder behaviour options
- On revising the persistence mechanism
It is noted that the GRI SEI message uses a single presence flag, but derives a variable that is used in the inference to distinguish between a value that persists vs. a value that is not applicable.
It is noted that the parameters controlled by the presence and persistence flags are considered likely to change infrequently.suggested that the persistence flag should apply to an individual camera id. The semantics for the persistence flag needs to be updated to apply to an individual camera.
Agreed to option 2, subject to review of text with modified persistence language to apply to the camera id.noted that the cancel flag in the current design cancels all camera_id values. It was questioned if that was the desired behaviour. Further study on this aspect is encouraged.
Proposal on quaternion is considered unnecessary given the adoption in JVET-AN0075.
It is recognized that the problem described is indeed a problem. Further study on the best solution is encouraged. There is concern that it is difficult to impose strict requirements on floating point numbers.
Further discussion was held on 10 Oct. 2025.
The text was confirmed.
JVET-AN0167 AHG9: On localization and mapping SEI message