Organisation internationale de normalisation

Liaisons

The following Liaison inputs were reviewed, and dispositions were prepared in coordination with JCT-VC and JCT-3V and other subgroups, as applicable.

1.1.1.1.1.1.1.1.23m36223 Liaison Statement from ITU-T SG 16 [ITU-T SG 16 via SC 29 Secretariat]

(next three related to HDR, handled by Requirements with input from Video)

1.1.1.1.1.1.1.1.24m36228 Liaison Statement from ITU-R SG 6 [ITU-R SG 6 via SC 29 Secretariat]

1.1.1.1.1.1.1.1.25m36358 ATSC Liaison on HDR

1.1.1.1.1.1.1.1.26m36818 DECE Liaison on DASH Text Vectors, HDR/WCG, ISOBMFF [Michael Dolan]

5. Joint Meetings

The following joint meetings were held (see notes, as applicable, in the corresponding sections and in other reports such as the JCT-VC and JCT-3V reports)

Joint Video/VCEG/Req/VC Mon 16:30-18:00

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  On the SCC extensions of HEVC - see JCT-VC report
  

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  On HDR:
  

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  all proposals use existing HEVC without low-level changes, with additional processing at the output
  
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  Plan a solution with at most an HLS-only approach (no change to core decoding process and low-level syntax), rapid standardization (not to issue a CfP due to limited scope and need to move quickly).
  
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  Identify need for new profile? To be studied and resolved by February 2016.
  
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  It was generally supported to perform the technical work jointly in JCT-VC, but necessary to communicate between parent bodies
  
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  Possibly an additional face2face meeting will be held in the period until next meeting.
  

Joint with Systems on resolution adaptation in DASH Tuesday 23 June 17:30-18:00

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  A breakout meeting was held jointly with Systems and JCT-VC (Tue 17:30-18:00 in the Video room) on DASH / resolution switching. WG 11 input M36167 from M. M. Hannuksela et al. on dynamic resolution adaptation for video streaming had been reviewed by MPEG Systems prior to the joint meeting, and was shortly summarized again (this is a follow-up of docs M35766 and M36037 of the 111th WG 11 meeting) was discussed, no specific action was planned, other than encouraging further study for future video coding developments.
  

1.1.1.1.1.1.1.1.27m36167 CE-SISSI: Supplemental property descriptor for seamless switching with open GOPs [M. M. Hannuksela, Y. Yan, P. Gendron, X. Ducloux]

Currently with HEVC, switching between streams (and potentially at the same time changing spatial resolution) is possible at IDR/IRAP pictures, which is hardly used in practice (due to overhead with closed GOP IDR pictures). A desire was expressed to allow switching at CRA positions as well (not just at IDR pictures) seamlessly, which is currenty supported only when no resolution change is done. Here it is requested to do this with reference picture resampling (to be specified normatively). The proponents of such technology were asked whether drift occurs, but this was said to be subjectively unnoticeable.

It was also mentioned that such an approach could be implemented by using SHVC (even without drift), where, however, there is some bit rate overhead and the necessity to implement two loops would be undesirable. Some provision for this usage was discussed previously for enabling an indication in high-level syntax that only one resolution layer will need to be decoded in each picture interval (to avoid the extra complexity of two-loop decoding), and this may already be supported in high-level syntax. The proposed solution could also be interpreted as lightweight SHVC, and even could be using the same filter design as for HEVC upsampling, however these would need to be run only at certain picture positions, similar to switching pictures in AVC. Also, although SHVC enables switching up in picture resolution in a predictive manner, it does not enable switching down in resolution predictively.

Conformant decoding would require defining a new profile to support this. Some concern was raised whether this would be justified for this specific case, where it would be questionable if that would ever be widely used. Even without a profile, it was suggested that decoders could be implemented running such a method in a non-conforming way, although this would presumably violate the current standard and cause interoperability problems with decoders not designed for it.

Further study of this is necessary. Several experts mentioned that such a functionality might be desirable in next-generation video coding.

Thursday 25 June 14:30-15:15 Joint meeting with VCEG and MPEG Requirements and Video

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  For new work on HDR video coding, it was reported that further management-level discussions at the parent-body level need to take place if the JCT-VC is to be given the mandate to work on this topic. Thus, the work toward standardization for this topic (except as otherwise noted) was to remain at the parent-body level for the time being.
  
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  Scalable lossless coding was discussed. A contribution m36373 had been submitted to MPEG by Fujitsu that reported a potential gain of 1–6% over JPEG 2000 for a scalable lossless coding scheme based on HEVC all-intra coding with a lossless enhancement. Further study of this was encouraged.
  
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  The ARIB EOTF/OETF U0032 and U0033 were approved to be considered by JCT-VC – see notes on those contributions.
  
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  On 4:2:0 chroma positioning for ITU-R BT.2020 video, a planned liaison communication with ITU-R WP6C was discussed (see notes for U0156)
  

6.