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39th Meeting: Daejeon, KR, June 2025 2025-05-30 01:20
AHG9: Miscellaneous changes for VSEI
Authors: Ye-Kui Wang ByteDance Jizheng Xu ByteDance
Abstract
This document contains the draft text for changes to the versatile supplemental enhancement information messages for coded video bitstreams (VSEI) standard (Rec. ITU-T H.274 | ISO/IEC 23002-7), to specify 15 additional SEI messages, namely 1) SEI processing order, 2) processing order nesting, 3) encoder optimization information, 4) source picture timing information, 5) object mask information, 6) modality information, 7) text description information, 8) digitally signed content initialization, 9) digitally signed content selection, 10) digitally signed content verification, 11) generative face video, 12) generative face video enhancement, 13) AI usage restrictions, 14) packed regions information, and 15) image format metadata. The changes also include updates to some of the existing SEI messages, including the two neural-network post-filter (NNPF) SEI messages, as well as some corrections to the previous version of the VSEI standard.
Meeting Notes
JVET-AM0047 AHG9: Miscellaneous changes for VSEI [Y.-K. Wang, J. Xu (Bytedance)]

JVET-AM0047 also relates to modality information, digital signed content, and NNPFC SEI messages

This contribution proposes the following changes for VSEI:

  1. Since SEI messages in the VSEI spec already have an extension mechanism to add extension data to the end of any SEI message syntax, for the modality information SEI message the extension mechanism through the syntax elements mi_modality_type_extension_bits and mi_reserved_modality_type_extension is asserted to be redundant and is thus proposed to be removed.
  2. When dsci_vss_implicit_association_mode_flag is equal to 1, dscs_verification_substream_id is inferred to be equal to MaxNumSubLrs * LayerId + SubLrId. However, currently dscs_verification_substream_id is coded as u(8), while it is asserted that a reasonably inferred value of dscs_verification_substream_id can easily be greater than 255. Therefore, it is proposed to
    1. Change the value range of dsci_num_verification_substreams_minus1 from 0..255 to 0..65 535.
    2. Change the coding of dscs_verification_substream_id and dscv_verification_substream_id from u(8) to u(16).
    3. Add the following constraint: The value of dscv_verification_substream_id shall be in the range of 0 to dsci_num_verification_substreams_minus1, inclusive. Note that such a constraint already exists for dscs_verification_substream_id.
  3. Since the semantics of the value 2 for nnpfc_scan_type_idc is specified, as an asserted bug fix, change "The value of nnpfc_scan_type_idc shall not be equal to 2." to be "The value of nnpfc_scan_type_idc shall not be equal to 3."
  4. Some asserted minor, purely editorial changes.

The detailed proposed text changes, marked relative to JVET-AL2006-v4, are included in an attachment to this contribution.

For aspect 1, it is noted that the modality information SEI message is new for VSEI v4.

Decision: Adopt item 1, item 3. Refer item 4 to editors.

Further discussion requested on item 2.

Further discussed 27 June 2025.

Side activity included discussion on items 2a and 2b. It was noted that JVET-AM0210 item 5 is related.

Decision: Adopt item 2c, constraint on value of dscv_verification_substream_id

JVET-AM0047 AHG9: Miscellaneous changes for VSEI

ARCHIVE :
JVET-AM0047-v1.docx JVET-AM0047-v1_VseiTextChanges.docx
Decisions
adopted
Adopt item 2c, constraint on value of dscv_verification_substream_id
JVET-AM0047 AHG9: Miscellaneous changes for VSEI
Citation