JVET-AN0178 VVC multilayer extension for an external base layer [F. Urban, Y. Chen, F. Galpin, E. François, P. de Lagrange, P. Bordes (InterDigital)]
Multilayer coding with an external base layer is a functionality that is available in SHVC but not yet in VVC. It is proposed to add this functionality to VVC.
Uses cases such as enhancing an HEVC or AVC legacy bitstream with a VVC enhancement layer are considered. To this end, it is proposed to follow a syntax similar to SHVC, adding an extension to the VPS to describe the format of the external base layer image, and adapt the decoding process to load the external pictures in the DPB.
In terms of reference software, it is noted that an implementation is already available in the NNVC software.
Was presented in JVET main track Friday 10 Oct. 1045 (chaired by JRO).
Inheritance of motion information from base layer would need to be switched off.
Signalling to be done similar as in SHVC, a change in VPS is proposed. This would require definition of a new profile.
No conformance could be defined in this context.
One expert reports that in terms of hardware, implementers of her company don’t see problems to extend chips that have multiple standards implemented.
Several experts expressed support.
More evidence would be requested about market needs to go into defining new VVC profile(s).
It should also be clarified if it would be necessary/beneficial to define at least a minimum level of conformance for the enhancement layer.
It was commented that this might be beneficial in a transition phase towards a new standard (one reference might be found in JVET-AK0236)
Also information would be beneficial about compression advantage, e.g. using a VVC enhancement layer on top of HEVC instead of using SHVC.
Conformance was defined in SHVC, and might be similarly done here.
Further study on those aspects.
Plenary meetings, joint meetings, BoG reports, and liaison communications
General
The following topics were discussed in JVET plenary Wednesday 8 Oct. 1115–1245:
- Liaison communication
- No incoming liaison statements had been received until late in the meeting when a late letter was made available from JPEG. See further notes in 7.5.
- Scheduling for the remaining week was discussed (further detail on scheduling is recorded in section 2.12)
- Joint meetings
- Review status from main track
- All EE1/EE2 reviewed, few revisits
- Many 4.x categories not reviewed yet, planned for today and tomorrow
- JVET main will not meet during ITU workshop on Friday afternoon, and during the MPEG information sharing sessions Thursday 9-10, Saturday afternoon
- Review status from HLS track and discussion on potential open issues
- First pass on all contributions related to VSEIv4, VVC, HEVC, nothing critical, waiting for some input on revisits after offline activities
- Initial review of ballot comments VSEI, review of DoCRs on Saturday morning
- Integration into JVET-AN2006 started, needs to be integrated into H.274, FDIS can have editing period. Same for HEVC (integration already started), VVC not yet touched (to be clarified with Gary)
- AVC related changes in JVET-AN1017 with editing period
- Around 40% first pass on TuC and new messages
- There are four contributions on support for Gaussian splat coding. As in parallel GS is also a topic of defining compression standards currently in WG 4 and WG 7, and they are still in the process of assessment of suitable technology, it would be premature to define such SEI messages in JVET. The contributions can be reviewed in terms of identifying syntactic correctness, to potentially help proponents to submit in a more mature shape for consideration in another WG. If proponents are not getting appropriate opportunity of presenting their idea in the other WGs, or having it assessed/compared with other technology that is investigated there, they should inform the JVET chair.
It was suggested to send a liaison to JPEG, to be reviewed on Sunday.
An initial review of modifications to be implemented in HEVC, VVC, VSEI and TuC was conducted in JVET at 1245 on Friday 11 Oct. No objections were raised. Final approval to be done on Sunday.
It was commented that for some SEI messages in TuC software implementation may be missing.
MPEG information sharing meetings
Information sharing sessions with other WGs and AGs of the MPEG community were held on Tuesday 7 Oct. 0900–1230 (the JVET meeting continued during that session, where only the JVET chair gave a brief report about achievements so far), Thursday 9 Oct. 0900–1000, and Saturday 11 Oct. 1400–1550.
The status and plans for the work in the MPEG WGs and AGs was reviewed at these information sharing sessions.
Joint meetings
Joint session 0830-1255 Wednesday 8 Oct. on next generation video standardization CfE / CfP: MPEG WG 2 / Requirements, MPEG WG 5 / JVET, MPEG AG 5 Visual Quality Assessment, and VCEG (ITU-T Q6/21)
This joint session was chaired by Jens-Rainer Ohm (JVET Chair and WG 5 Convenor), Gary Sullivan (VCEG Rapporteur and SC 29 Chair), Mathias Wien (AG 5 Convenor), and Jörn Ostermann (AG 2 Convenor), on behalf of Igor Curcio (WG 2 Convenor).
A joint meeting of Q6/21 with JVET, MPEG WG 2 Requirements and MPEG AG 5 Visual quality assessment was held on Wednesday 8 October 2025 to discuss the potential development of a next-generation video coding standard. A joint “Call for Evidence” (CfE) for potential development of such a standard had been issued from the interim JVET meeting of July 2025 (as JVET-AM2026). This section describes the discussions held in this joint meeting.
Notes were taken by G. J. Sullivan.
Submissions responding to the CfE
Submissions responding to the CfE were summarized as follows:
- All submissions were based on the VTM, ECM or NNVC software codebases developed in JVET.
- For the compression efficiency test case (CP), the evaluated cases were described as:
- ECM + 4 submissions + anchor
- All but one submission in all test categories
- No additional coding tools were submitted that had not been previously studied in JVET (e.g. in the ECM of NNVC studies)
- For the runtime test case (RT), schemes were targeting 0.2× to 5× VTM encoder runtimes, and the responses were described as:
- ECM_2x + 15 submission variants + anchor
- All submissions responded to all test categories
- Evaluated on subset of test sequences
- For the functionality test (FC) (error concealment) test case, the responses were described as:
- One submission was submitted with subset of test sequences
JVET document JVET-AN0361 reported visual results:
- Many test cases ~76/120 had at least one submission that had a non-overlapping confidence interval with the VVC VTM.
- Some show improved compression with substantially less encoder complexity.
- Many cases had neural network technology showing a clear visual benefit (beyond the measured PSNR benefit)
- One submission with 0.2× encoder runtime had visual benefit and ~1.4× decoder runtime.
- The test methodology used absolute category rating (ACR) with a hidden reference. There were 873 viewers, 2 131 test cases and 50 146 votes.
- Testing was generally according to ITU-R BT.500, and few outliers were found.
JVET-AN0056 (C334) On Next Generation Video Codec Call for Proposal Timing [S. Wenger (Tencent)])
The proponent suggested that the relevant groups should target a CfP issue date no earlier than the July 2026 meeting, with a CfP evaluation no earlier than the spring 2027 meeting, following the WP3/21 meeting cadence. The proponent perceived no immediate business need and expressed a desire for time for industry to clarify the direction of intended work.
A participant commented that there is competition and advocated that we should provide a competitive standard in response. Others said they did not see urgency and readiness for the type of content that is highest priority.
It was commented that July 2026 vs April 2027 seem to be the two primary requested timelines for CfP response deadlines, and it was suggested that January 2027 is a reasonable compromise time. Not proceeding too quickly was said to be justified by the need to study template methods and neural network-based methods, which need time for study in preparation of a good CfP proposal.