JVET-AM0165 AHG9: On value range and reserved values for syntax elements in VSEI v4 [J. Nam, H. Tan, J. Lee, C. Kim, J. Lim, S. Kim (LGE)]

JVET-AM0165 also relates to the EOI, MI, TDI, and IFM messages

(Related to SPTI SEI message)

1. On value range of spti_source_type in SPTI SEI

(Related to MI SEI message)

2. On value range of mi_modality_type in MI SEI

3. On reserved value of mi_modality_type in MI SEI

(Related to EOI SEI message)

4. On reserved value of eoi_type in EOI SEI

5. On reserved value of eoi_object_based_idc in EOI SEI

6. On reserved value of eoi_privacy_protection_method_idc in EOI SEI

7. On reserved value of eoi_privacy_info_type in EOI SEI

(Related to IFM SEI message)

8. On reserved value of ifm_type_id[ i ] in IFM SEI

(Related to TDI SEI message)

9. On reserved value of tdi_descr_purpose in TDI SEI

10. On reserved value of tdi_descr_id in TDI SEI

Regarding item 1, in the current design of source picture timing information (SPTI) SEI message, the syntax element spti_source_type is defined using bitmask operations in the range of 0x01 to 0x80, which means there are 8 bits out of the 16 bits allocated for this signalling have been specified. However, the current semantics of spti_source_type specify that its value range is from 0 to 127, and the decoder is designed to ignore spti_source_type values from 128 to 255.

Item 2 is related to JVET-AM0047 item 1. No action.

Item 3 proposes typical language regarding reserve values, which was missing.

Item 4 clarifies the behavior of decoders regarding reserved values of eoi_type.

Item 5 clarifies the behavior of decoders regarding reserved values of eoi_object_based_idc.

Item 6 fixes a bug in the reserved range of values of eoi_privacy_protection_method_idc to be 65535 rather than 255, since the syntax element is u(16), and also clarifies the behavior of decoders regarding reserved values.

Item 7 clarifies the behavior of decoders regarding reserved values of eoi_privacy_info_type

Item 8 proposes the following for ifm_type_id[ i ]:

When the value of ifm_type_id[ i ] is in the range of 7 to 255, inclusive, decoders conforming to this version of this document shall ignore all information for the i-th loop of the image format metadataifm_type_id[ i ].

It was suggested that the “i-th loop” language is imprecise.

The spirit of the proposal is to ignore the i-th entry, which is agreed. It was suggested to use “i-th image format metadata payload” .

Item 9 proposes the following text for tdi_descr_purpose : When the value of tdi_descr_purpose is in the range of 7 to 255, inclusive, dDecoders conforming to this version of this document shall ignore the text description information SEI message.allow any value of text_descr_purpose in the range of 0 to 255, inclusive.

Item 10 proposes to reserve some values of tdi_descr_id.

It was suggested to remove the “with the tdi_descr_id” in the proposed text.

Decision (Bug fix): Adopt item 1 for SPTI, item 3 for modality reserved value, item 4 for eoi_type, item 5 for eoi_object_based_idc, item 6 for eoi_privacy_protection_method_idc, item 7 for eoi_privacy_info_type, item 8 with replacing “i-th loop” with “i-th image format metadata payload”, item 9 or tdi_descr_purpose., item 10 with removing “with the tdi_descr_id” wording.

Modality information SEI message (1)

Contributions in this area were discussed during 1900–1930 on Friday 27 June 2025 (chaired by J. Boyce).

JVET-AM0165 AHG9: On value range and reserved values for syntax elements in VSEI v4

SEI processing order (SPO) and processing order nesting (PON)