VPSG summary report to FES-TF - draft 2013/9/11

Transcription

1 VPSG summary report to FES-TF - draft 2013/9/11

2 Video Performance Study Group (VPSG) Charter To study input from members and invited experts and provide a r ecommendation to FEST on The video parameters, outlined in the FEST Proposal for Study Groups and the corresponding Studio and 8C Position documents, to be implemented in the FE to enable the best video performance that the format can effectively deliver. The impact of graphics blending for QuadHD support The recommendations should consider the benefits and drawba cks as well as the cost and schedule for implementation of the f eatures.

3 VPSG Status 1. Activities: 8 weekly telcos, 2 days F2F August 7th & 8th including demos, many break out small gp discussions 2. Participants: BoD member companies Invited experts: MediaTek 3. Topics discussed: Comparison Criteria: Eval metrics, Subjective evaluation Test Color subsampling: 422/444 vs XYZ subsampling - YDxDz Bit depth: 12bit vs. 10bit WCG: XYZ vs. BT.2020 HDR Metadata: WCG/HDR Gfx blending DCSG request on peak bitrate High Frame Rates: HDMI support

4 High Level Summary of Discussions (1/2) Subjective Evaluation Tests Many members stressed importance of basing decisions on subjective evaluation tests. However, given the V PSG group s 2 month+ schedule, there was not adequate time for conducting subjective evaluation tests. Me mbers should take note of following difficulties for any further studies: Preparation of Critical but not unduly so content : Finding content satisfying such characteristics content is time consuming. Clip license issues In some cases test content needs to be created which requires budget and time. Conducting BT.500 tests requires careful preparation Planning, cross coordination, is both resource and time consuming. Many of the test items were interrelated, leading to a large matrix of comparison items. Involving third party organizations comes with a cost. Lack of Test Environments Some of the tests were critically limited by the availability of equipment. For example displays with high luminance, and >12bit bit depth are limited to on e companies lab, leading to difficulty to cross examination results. Within the given timeframe, VPSG was limited to conducting a picture quality viewing test session at the Augu st F2F in LA to compare the following (conclusions in following slides): Color subsampling: Baseband signal comparison of 420/422/444 Bit depth: Baseband signal comparison of 10 vs 12bit HDR PQ peak 10Knit (both XYZ and BT.2020)

5 High Level Summary of Discussions (2/2) Other input was provided for comparison studies: Evaluation Metrics: de2000, PSNR Pros/Cons analysis consolidated from all members Workflow comparisons Straw Polls: Conducted 2 Straw Polls for the following items 1st on 9/5, 2nd on 9/11 (see attached results for details) Bit Depth: 12bit vs 10bit => majority supported 10bit. No super majority reached. WCG: XYZ vs BT.2020 => majority supported BT No super majority reached. Color subsampling: 422/444 vs 420 => super majority voted for 420 and to vote down 422/444 A 3rd Straw Poll was conducted based on Studios/Dolby request: Results TBD. Open Issues: WCG and bit depth: As noted above, majority support for BT.2020 and 10bit, but did not reach super majority. Further discussion needed to conclude recommendation. There was insufficient time to discuss the following topics in detail to reach a conclusion. Recommendation is for successor gp to continue study. HDR Metadata Frame Rate Gfx blending Further peak bitrate study for DCSG

6 Study Items List summary (1/3) Item Evaluation Metrics Subjective Evaluation Tests Color Subsampling 420/422/444 Sampling Bit Depth 10/12bit: Study items Subjective Quality - ITU-R BT Double Stimulus Continuous Quality Scale (DSCQS) => Not conducted due to insufficient time Compression efficiency PSNR => Used for SDR compression tests Color difference and bit efficiency - Delta E2000 => utilized with JND Patch from Dolby. Many comments to base decisions on subjective evaluation. Identified tests environments, such as ref displays etc. Conducted picture quality viewing tests for color subsampling and bit depth. Insufficient time to conduct subjective evaluation tests. Compression efficiency => Sony/Dolby conducted tests but were not able to conclude in time. General comments from both companies were that 420 does provide better compression efficiency and that 422/444 would require a higher bitrate. Cost impact => Detailed analysis from MediaTek describing cost increase and design complexity increase for 422/444. XYZ subsampling => studios introduced YDzDx for subsampling. Subjective quality eval => Performed for baseband signal. Difference subtle. Pros/Cons => Consolidated from all members. Contouring w HDR/WCG => DE2000 results from Dolby JND Cross test indicates 10bit 10Knit PQ XYZ banding more evident than current BD for critical nit area. 10Knit 10bit PQ 2020 shows improvement over current BD for most of nit area. 12bit 10Knit PQ shows further improvement with XYZ having larger DE2000 than Compression efficiency => Not studied. Cost impact (including tone/gamut mapping 3D LUTs) => Analysis from MediaTek describing cost increase for 12bit over 10bit. CE mfrs provided further input on areas of cost increase. Gfx related cost impact not studied. Dolby provided input on EDR (dual coding) implementation cost studies. Subjective quality eval => Performed at F2F but difficulty in finding critical content. For critical content, differences were seen, but varying impressions on what is good enough and inconclusive. Pros/Cons => Consolidated from all members.

7 Item WCG - BT.2020 vs XYZ: Study items Study Items List summary (2/3) Color volume => Dolby provided info for study. XYZ volume extends significantly beyond visible locus. Metadata => Proposal by studios to carry ref display parameters. Studied in small gp. and generally positive comments on supporting ref display peak luminance, color primaries and white point information. Details to be studied in successor gp. Workflow => Sony provided workflow study. Color space conversion 3x3 matrix, mapping to legacy 709 => ITU-R BT.2250 specified conversion. Gamut mapping 3D LUT? Mapping to legacy 709 => SMPTE introduced by studios for how to utilize metadata. Gamut mapping needs to be studied further. Player, TV & interface processing limitations => CE mrfs and MTK provided study results explaining limitations on interface and codec support Cost impact. => CE mfrs and MTK provided study results on XYZ impact. Many issues listed including additional bit depth, memory, Xfm circuitry, design/dev cost for additional modules/algorithms for XYZ. Standardization TBD, compression concerns, practical constraints, SoC complexity. Pros/Cons => Consolidated from all members. XYZ proponents pitch is that it covers all perceivable colors and is future proof, and that it fosters innovation. Arguments against it are that it introduces further quantization errors, and has no commercial value when displays are not expected to cover even BT.2020 for the foreseeable future. BT.2020 proponents pitch is that it is defined as the ITU UHDTV standard with expectation to be adopted by numerous UHDTV standards, and alignment for UHDTV standards will be beneficial to the industry. Arguments against it are that it does not cover the entire human visible locus and the format may need to be revisited when exploring beyond BT HDR Metadata - artistic intent, how to interface with player and/or display => Pending study for HDR scheme. Workflow => Presented Dolby reference workflow, and Sony provided study on differences for XYZ vs Peak brightness/luminance visual preference, display limitations, bit depth.. => Dolby provided internal results from HDR experiments. Successor gp to study further. OETF/EOTF transfer curve 709/1886, PQ, => Dolby and Philips EOTF proposals. Philips/Dolby conducted comparisons, where performance results were similar. Recommendation was to wait for ITU-R Rapporteur Gp study results. Tone mapping mapping to various peak brightness displays and legacy 709, 3D LUT? => Not studied yet. Successor gp to study futher.

8 Item Study Items List summary (3/3) Study items Frame rates (fps) HDMI status w 48fps prepare letter to HDMI (need BoD vote). Confirm HDMI2.0 release timing. => Initial liaison letter sent. Liaison Ian Harvey FES-TF Chair. Awaiting response. HDMI 2.0 announcement was made Sept 4th. 48fps not supported. Recommended proponents to contact HDMI forum, and also study work around for legacy displays that do not support 48fps. TV implementation concerns => Not studied Peak Bitrate DCSG request As many of the video parameters were not finalized, was not possible to provide additional info above bitrate numbers discussed in FEST and provided by Technicolor, Sony. Past FEST numbers were forwarded to DCSG. Further studies on peak bitrate to be conducted by successor gp. Gfx Plane Blending Determine Requirements => Oracle presentation on BD-J related Gfx blending impact. Further studies in successor gp.

9 Open Issues summary WCG and bit depth: As noted above, majority support for BT.2020 and 10bit, but did not reach super majority. Further discussion needed to conclude recommendation. Metadata Study WCG/HDR metadata details and discuss approach to relevant standardization bodies. Details summarized in VPSG HDMI Conclusions_ b.pptx. HDR Create successor Gp to study following scope: EOTF VPSG recommendation is to wait for ITU-R Rapporteur Group study results on HDR EOTF. Dolby indicated that study results could be as early as Nov Subjective Evaluation Tests Peak Luminance Tone Mapping Gamut Mapping Other Gfx Blending Video parameters need to be fixed first. Where to discuss? - FEST or successor Gp? Frame Rates HDMI p missing. HDMI soliciting input and proposal for next version. Recommended proponents to: Contact HDMI regarding 48p Study a solution to work around legacy displays that do not support 48p signaling; e.g. convert to 60P/24P, etc. Peak Bitrate studies for DCSG To continue in successor group

10 2013/9/5 VPSG Straw poll #1 RESULTS

11 Straw poll items Straw Poll instructions Take straw polls for the following features. Members are expected to take into account all the information/data points /demo results discussed in VPSG. Bit depth: 12 or 10bit WCG: XYZ or BT.2020 Color sub-sampling: 420 or 422/444 Opinions can be cast as follows by BOD companies. Vote is not A or B, so can vote for A and B independently. Yes No Abstain If poll exceeds Super Majority (66.7%), it will be considered as the VPSG recommendation to FEST. 1st Straw Poll will be conducted in Telco-7. If super majority is not reached on the items, a 2nd straw poll will be con ducted on Sept 11 Wrap Up telco. If super majority is not reached at that point, the study report to FES-TF will be th at no recommendation was reached on that item. Study results will be submitted to FES-TF.

12 Panasonic x Panasonic x Voting item: Agree to recommend FES-TF/BoD to create BDFE format with a bit depth of 12bit as discussed in FES-TF/VPSG. Straw Poll #1 results - Bit Depth For 1st straw poll no super majority reached on both items. 2nd straw poll to be conducted on Sept 11 VPSG wrap up call. Voting item: Agree to recommend FES-TF/BoD to create BDFE format with a bit depth of 10bit as discussed in FES-TF/VPSG. Yes No Abstain Yes No Abstain Disney x Disney x Dolby x Dolby x DTS x DTS x Fox x Fox x Hitachi x Hitachi x Intel x Intel x LGE x LGE x Mitsubishi x Mitsubishi x Oracle x Oracle x

13 Straw Poll #1 results - Wide Color Gamut For 1st straw poll no super majority reached on both items. 2nd straw poll to be conducted on Sept 11 VPSG wrap up call. Voting item: Agree to recommend FES-TF/BoD to create BDFE format with an XYZ color gamut (EOTF TBD) as discussed in FES- TF/VPSG. Voting item: Agree to recommend FES-TF/BoD to create BDFE format with a BT.2020 color gamut (EOTF TBD) as discussed in FES-TF/VPSG. Yes No Abstain Yes No Abstain Disney x Disney x Dolby x Dolby x DTS x DTS x Fox x Fox x Hitachi x Hitachi x Intel x Intel x LGE x LGE x Mitsubishi x Mitsubishi x Oracle x Oracle x

14 Panasonic x Panasonic x Straw Poll #1 results - Color Sub-sampling 420 reached super majority and will be VPSG recommendation to FEST for color sub-sampling. 422/444 was voted down with super majority. Voting item: Agree to recommend FES-TF/BoD to create BDFE format with 422/444 color sub-sampling as discussed in FES-TF/VPSG. Voting item: Agree to recommend FES-TF/BoD to create BDFE format with 420 color sub-sampling as discussed in FES-TF/VPSG. Yes No Abstain Yes No Abstain Disney x Disney x Dolby x Dolby x DTS x DTS x Fox x Fox x Hitachi x Hitachi x Intel x Intel x LGE x LGE x Mitsubishi x Mitsubishi x Oracle x Oracle x

15 2013/9/11 VPSG Straw poll #2 RESULTS

16 Panasonic x Panasonic x Voting item: Agree to recommend FES-TF/BoD to create BDFE format with a bit depth of 12bit as discussed in FES-TF/VPSG. Straw Poll #2 results - Bit Depth For 2nd straw poll majority voted for 10bit but no super majority reached on both items. Voting item: Agree to recommend FES-TF/BoD to create BDFE format with a bit depth of 10bit as discussed in FES-TF/VPSG. Yes No Abstain Yes No Abstain Disney x Disney x Dolby x Dolby x DTS x DTS x Fox x Fox x Hitachi x Hitachi x Intel x Intel x LGE x LGE x Mitsubishi x Mitsubishi x Oracle x Oracle x

17 Straw Poll #2 results - Wide Color Gamut For 2nd straw poll majority voted for BT.2020 but no super majority reached on both items. Voting item: Agree to recommend FES-TF/BoD to create BDFE format with an XYZ color gamut (EOTF TBD) as discussed in FES- TF/VPSG. Voting item: Agree to recommend FES-TF/BoD to create BDFE format with a BT.2020 color gamut (EOTF TBD) as discussed in FES-TF/VPSG. Yes No Abstain Yes No Abstain Disney x Disney x Dolby x Dolby x DTS x DTS x Fox x Fox x Hitachi x Hitachi x Intel x Intel x LGE x LGE x Mitsubishi x Mitsubishi x Oracle x Oracle x

18 2013/9/11 VPSG Straw poll #3 RESULTS

19 Straw Poll #3 results - Bit Depth TBD (pending straw poll at 3:15pm, Sept 11, CEDT ) Voting item: TBD Yes No Abstain Disney Dolby DTS Fox Hitachi Intel LGE Mitsubishi Oracle Panasonic Philips

20 Recommendation to FES-TF Topic Recommendation Comments Color Subsampling 420 Super majority voted on 420. Super majority voted down 422/444. Bit Depth TBD Majority voted for 10bit. However, no super majority reached. WCG TBD Majority voted for BT However, no super majority reached. HDR Metadata Gfx blending High Frame Rates Peak bitrate for DCSG Successor Gp to continue study as described in this report Successor Gp to continue study as described in this report Successor Gp to continue study as described in this report Successor Gp to continue study as described in this report Successor Gp to continue study as described in this report

21 EOF