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39th Meeting: Daejeon, KR, March 2025 2025-03-19 22:00
AHG9: On DSCI content UUID
Authors: Yun Li SJTU Jizheng Xu ByteDance Ye-Kui Wang ByteDance K. Yang SJTU Y. Xu SJTU
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-AL0116 AHG9: On DSCI content UUID [Y. Li (SJTU), J. Xu, Y.-K. Wang (Bytedance), K. Yang, Y. Xu (SJTU)]

Currently, the content UUID is required to be present when there is at least one independent non-base layer (INBL). The motivation can be seen from the JVET-AK meeting minutes for JVET-AK0287: "For independent non-base layer, uuid is required to be included for verification to avoid tampering." However, if an INBL is depended by a higher layer, then tempering of the INBL can be detected. Therefore, it is asserted that dependency by higher layers should also be taken into consideration on requiring the presence of content UUID.

This contribution proposes such changes to the DSCI SEI message semantics.

The changes are summarized as follows:

  1. Replace the variable IndependentNonBaseSubstreams with NumFullyIndependentSubstreams, which is derived to be equal to the number of substreams that do not depend on other substreams and are not depended by other substreams.
  2. When dsci_key_retrieval_mode_idc is equal to 0 or NumFullyIndependentSubstreams is greater than 0, dsci_content_uuid_present_flag shall be equal to 1.

The detailed proposed text changes are provided in an attachment to this contribution. The changes are marked relative to the spec text provided in JVET-AL0103, which includes asserted purely editorial changes to the DSC SEI messages based on JVET-AK2006-v1.

A fully independent substream does not have any other substreams that depend on it, in addition to not depending on another substream.

It was suggested that the original design intent for requiring the UUID for independent non-base layers was to avoid tampering.

The proposal relaxes the requirements for presence of UUID so that it doesn’t apply in as many cases as the existing design.

No action was taken on this.

ARCHIVE :
JVET-AL0116-v1.docx JVET-AL0116_vseiSpecText-v1.docx
Decisions
No action was taken on this.
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