JVET-E0056 AHG8: An improvement on the compact OHP layout [H.-C. Lin, C.-C. Huang, C.-Y. Li, Y.-H. Lee, J.-L. Lin, S.-K. Chang (MediaTek)]

(Chaired by JB and JRO.)

This contribution proposes an improvement on the compact octahedron projection (OHP) layout by rotating 90-degree on the octahedron. As compared to the original compact OHP layout in the previous contribution JVET-D0142, the experimental results reportedly demonstrate that the BD-rate reduction provided by the proposed layout achieves 6.0%, 5.8%, 6.8% and 6.6% in S-PSNR-NN, WS-PSNR, S-PSNR-I, and CPP-PSNR, respectively, while the memory footprint of the line buffer is also reduced.

(The slide deck presented was different from the upload, and was requested to be updated.)

This new layout avoids discontinuities around the equator. It shows a 6% gain vs old COHP layouts (3% rate reduction in E2E-WSPSNR), and a 0.8% loss vs. ERP.

These layouts assume a 2:1 aspect ratio and a representation of the entire 360x180 sphere.

Decision (SW): Replace previous COHP1 by this; still keeping COHP2.

JVET-E0056 AHG8: An improvement on the compact OHP layout [H.-C. Lin, C.-C. Huang, C.-Y. Li, Y.-H. Lee, J.-L. Lin, S.-K. Chang (MediaTek)]

Replace previous COHP1 by this, still keep COHP2.

Project planning

JEM description drafting and software

The following agreement has been established: the editorial team has the discretion to not integrate recorded adoptions for which the available text is grossly inadequate (and cannot be fixed with a reasonable degree of effort), if such a situation hypothetically arises. In such an event, the text would record the intent expressed by the committee without including a full integration of the available inadequate text.

Plans for improved efficiency and contribution consideration

The group considered it important to have the full design of proposals documented to enable proper study.

Adoptions need to be based on properly drafted working draft text (on normative elements) and HM encoder algorithm descriptions – relative to the existing drafts. Proposal contributions should also provide a software implementation (or at least such software should be made available for study and testing by other participants at the meeting, and software must be made available to cross-checkers in EEs).

Suggestions for future meetings included the following generally-supported principles:

No review of normative contributions without draft specification text

JEM text is strongly encouraged for non-normative contributions

Early upload deadline to enable substantial study prior to the meeting

Using a clock timer to ensure efficient proposal presentations (5 min) and discussions

The document upload deadline for the next meeting was planned to be Thursday 23 March 2017.

As general guidance, it was suggested to avoid usage of company names in document titles, software modules etc., and not to describe a technology by using a company name.

General issues for Experiments

Note: This section was drafted during the second JVET meeting, and is kept here for information about the EE procedure.

Group coordinated experiments have been planned. These may generally fall into one category:

"Exploration experiments" (EEs) are the coordinated experiments on coding tools which are deemed to be interesting but require more investigation and could potentially become part of the main branch of JEM by the next meeting.

A description of each experiment is to be approved at the meeting at which the experiment plan is established. This should include the issues that were raised by other experts when the tool was presented, e.g., interference with other tools, contribution of different elements that are part of a package, etc. (E. Alshina will edit the document based on input from the proponents, review is performed in the plenary)

Software for tools investigated in EE is provided in a separate branch of the software repository

During the experiment, further improvements can be made

By the next meeting it is expected that at least one independent party will report a detailed analysis about the tool, confirms that the implementation is correct, and gives reasons to include the tool in JEM

As part of the experiment description, it should be captured whether performance relative to JEM as well as HM (with all other tools of JEM disabled) should be reported by the next meeting.

It is possible to define sub-experiments within particular EEs, for example designated as EEX.a, EEX.b, etc., where X is the basic EE number.

As a general rule, it was agreed that each EE should be run under the same testing conditions using one software codebase, which should be based on the JEM software codebase. An experiment is not to be established as a EE unless there is access given to the participants in (any part of) the TE to the software used to perform the experiments.

The general agreed common conditions for single-layer coding efficiency experiments are described in the output document JVET-B1010.

Experiment descriptions should be written in a way such that it is understood as a JVET output document (written from an objective "third party perspective", not a company proponent perspective – e.g. not referring to methods as "improved", "optimized" etc.). The experiment descriptions should generally not express opinions or suggest conclusions – rather, they should just describe what technology will be tested, how it will be tested, who will participate, etc. Responsibilities for contributions to EE work should identify individuals in addition to company names.

EE descriptions should not contain excessively verbose descriptions of a technology (at least not unless the technology is not adequately documented elsewhere). Instead, the EE descriptions should refer to the relevant proposal contributions for any necessary further detail. However, the complete detail of what technology will be tested must be available – either in the CE description itself or in referenced documents that are also available in the JVET document archive.

Any technology must have at least one cross-check partner to establish an EE – a single proponent is not enough. It is highly desirable have more than just one proponent and one cross-checker.

Some agreements relating to EE activities were established as follows:

Only qualified JVET members can participate in an EE.

Participation in an EE is possible without a commitment of submitting an input document to the next meeting.

All software, results, documents produced in the EE should be announced and made available to all EE participants in a timely manner.

A separate branch under the experimental section will be created for each new tool include in the EE. The proponent of that tool is the gatekeeper for that separate software branch. (This differs from the main branch of the JEM, which is maintained by the software coordinators.)

New branches may be created which combine two or more tools included in the EE document or the JEM. Requests for new branches should be made to the software coordinators.

Don’t need to formally name cross-checkers in the EE document. To promote the tool to the JEM at the next meeting, we would like see comprehensive cross-checking done, with analysis that the description matches the software, and recommendation of value of the tool given tradeoffs.

Timeline:

T1 = JEM5.0 SW release + 4 weeks: Integration of all tools into separate EE branch of JEM is completed and announced to JVET reflector.

Initial study by cross-checkers can begin.

Proponents may continue to modify the software in this branch until T2

3rd parties encouraged to study and make contributions to the next meeting with proposed changes

T2: JVET-F meeting start – 3 weeks: Any changes to the exploration branch software must be frozen, so the cross-checkers can know exactly what they are cross-checking. An SVN tag should be created at this time and announced on the JVET reflector.

This procedure was again confirmed during the closing plenary of the third JVET meeting. It was further confirmed that the Common Test Conditions of JVET-B1010 are still valid, however the CTC encoder setting will be reflected in the config file that is attached to the JEM4.0 package.

Software development and anchor generation

Software coordinators will work out the detailed schedule with the proponents of adopted changes.

Any adopted proposals where software is not delivered by the scheduled date will be rejected.

The planned timeline for software releases was established as follows:

JEM5.0 including all adoptions from section 10.4 will be released by 2017-02-06.

The results about coding performance of JEM5.0 will be reported by 2017-02-17.

Further versions may be released for additional bug fixing, as appropriate

Encoder software optimized for luma-dependent quantizer adaptation will be ported as separate branch by the AHG on HDR/WCG within two weeks after JEM5.0 release.

A bug tracker for 360° video will be established as part of JEM bug tracker.

Timeline of 360Lib2.0: 4 weeks after the meeting (2017-02-17).

Further versions may be released as appropriate for bug fixing.

Timelines and volunteers for CfE anchors:

For SDR: See under BoG JVET-E0132

For 360° HM anchors: Samsung, InterDigital will provide them until Feb. 15, Qualcomm does cross-check. Generation of JEM anchors will be done under AHG mandates until next meeting.

For HDR, Qualcomm, Sharp, Technicolor and Netflix will provide/crosscheck HM anchors by Feb. 15. Generation of JEM anchors will be done under AHG mandates until next meeting.

As it is unlikely that HM 16.15 would be available in time, HM 16.14 should be used with appropriate config file changes.

Output documents and AHGs

The following documents were agreed to be produced or endorsed as outputs of the meeting. Names recorded below indicate the editors responsible for the document production.