JVET-AP0019 JAhG on GSC Report [W. Husak, J. Jung]

The image below provides an overall representation of the contributions to this meeting (boxes on a white background), along with a brief historical reminder.

An SEI message contribution (JVET-AP0194) to support Gaussian splats representation was made in January, and an update is proposed at this meeting, suggesting a common format with V-PCC.

Another contribution (JVET-AP0213) reports usage of implicit representation through SEI message, for Gaussian splats; it comes with a cross check and a demo (JVET-AP0220).

The SEI message for Gaussian Splats representation was initiated by ByteDance at the July 2025 meeting. This contribution was updated and submitted by a group of companies at the next two meetings, and then again at this meeting (JVET-AP0100). This contribution comes with a proposal for reference software, which has received two cross checks, and experimental results.

In addition, six contributions build on the syntax proposed in JVET-AP0100 to suggest technical updates. In particular, contribution JVET-AP0079 establishes a link with the implicit representation proposals.

List of contributions

The contributions are listed below, separated into categories:

• First, the contributions that include the implicit representation, the connection with the joint format with V-PCC, and the generic SEI contribution JVET-AP0100.
• The second category includes all the proposed improvements based on JVET-AP0100.
• The third category concerns software, results and demos.

Contributions related to proposed SEI messages:

• m76464 / JVET-AP0194 (Nokia): [GSC][JEE6.9] Common picture format for Gaussian splats coding
• JVET-AP0195 (Nokia): AHG9: Splatting information SEI with patches
• m76926 / JVET-AP0100 (Qualcomm, Tencent, Bytedance): [GSC][JEE6.9] Gaussian splatting information SEI message
• m76927 / JVETAP0101 (Qualcomm, Tencent, Bytedance): [GSC][JEE6.9] GSI SEI message workflow and packing examples
• m76929 / JVET-AP0213 (HHI): [GSC][JEE6.9] On implicit representations with the Gaussian splatting information SEI message
• JVET-AP0256 (SKKU): Crosscheck of JVET-AP0213 (AHG9: On implicit representations with the Gaussian splatting information SEI message)

Contributions related to updates of JVET-AP0100:

• m76701 / JVET-AP0225 (Tencent): [GSC][JEE6.9] Extended gaussian splatting information SEI message with SH non-uniform quantization and 2D transforms
• m76702 / JVET-AP0227 (Tencent): [GSC][JEE6.9] Content-adaptive packing order optimization for 3D Gaussian splatting video coding
• m76839 / JVET-AP0108 (ETRI): [GSC][JEE6.9] On Gaussian Splatting Information SEI message
• m76840 / JVET-AP0109 (ETRI): [GSC][JEE6.9] Enhancements to the Gaussian Splatting Information SEI message
• m76855 / JVET-AP0079 (Dolby): [GSC][JEE6.9] Triplane video-based implicit Gaussian splatting with a scaffold-based anchor point framework
• m76928 / JVET-AP0205 (Qualcomm, Tencent): [GSC][JEE6.9] On the GSI SEI message for spatial random access

Contributions related to software, experimental results, demos:

• m76091(Tencent, Qualcomm): [GSC][JEE6.9] VSEI-based software availability – Already presented.
• m76700 / JVET-AP0223 (Tencent): [GSC][JEE6.9] Software implementation and results of the GSI SEI message with HM, HM-SCM, and VTM
  • m76675 (ETRI): [GSC][JEE6.9] Cross-check Report on VSEI-based software
  • m76932 (Nokia): [GSC][JEE6.9] Crosscheck of m76700 Software implementation and results of the GSI SEI message with HM, HM-SCM, and VTM
• JVET-AP0220 (HHI): AHG9: Showcase for Real-time Decoding using Video-based Implicit Representations for 4DGS

Misc:

• m76944 (Qualcomm, Dolby): [GSC][JEE6.9] Summary report of JEE6.9 on evaluation of encapsulation methods for Gaussian Splats

Recommendations

• Determine whether the scope should include topics such as image or video, format such as I-3DGS or another format, and fast track or not.
• Include the designed SEI from one or more SEI’s (based on AP0100) into the TuC of VSEI for more study to support the scope. Base the SEI on the common picture format (AP0194).
• Establish a software codebase for experimentation to allow study of encapsulation of metadata related to Gaussian Splat packing in video streams in SEI messages.
• Define the next JEEs such that improved methods of GS packing in video streams can be assessed independent of the metadata packing.

The report of the Joint AhG on Gaussian splats JVET-AP0019 was verbally presented after the Sunday JAhG meeting during the JVET plenary on Monday, and the written report was shortly presented during the JVET plenary on Friday

Project development (42)

AHG1: Deployment and advertisement of standards (2)

Contributions in this area were discussed during 1530–1545 on Monday 27 April 2026 (chaired by JRO).