Corrigendum 4 to ISO/IEC 14496-2 was approved with some editorial improvements as suggested by the maintenance AHG and an NB comment. Other work on maintenance (in particular software cleanup) was stalled due to the difficulties for delegates with traveling to the meeting. An AHG was appointed (N11276, as recorded in N11242) to further the work until the 93rd meeting.
Documents reviewed:
m17363
Ad Hoc Group on Maintenance of MPEG-4 Visual related Documents, Reference Software and Conformance
Yi-Shin Tung, Jens-Rainer Ohm
m17403
Summary of Voting on ISO/IEC 14496-2:2004/DCOR 4
SC 29 Secretariat
Documents approved:
No.
Title
TBP
Available
11261
Disposition of Comments on ISO/IEC 14496-2:2004/DCOR 4
N
10/04/23
11262
Text of ISO/IEC 14496-2:2004/COR 4
N
10/05/31
2Development of AVC
The video subgroup held a session jointly with VCEG (ITU-T SG16 Q.6) to review input documents related to AVC.
M17542 reports dissatisfaction with the specification of MaxDpbFrames for MVC. MaxDpbFrames determines the required decoded picture buffer capacity in units of frames. In this contribution, it was asserted that the condition set for MaxDpbFrames is too strict and that this shows some disadvantages. It was proposed to increase the value of MaxDpbFrames for the MVC High profile as a corrigendum change. This is not a proposal to increase the memory capacity, but rather to increase the maximum number of frames (e.g., when operating at a smaller frame size than the maximum supported in the level). This issue requires further study, as we should be cautious about considering increasing the capacity requirement after finalizing the standard. It was noted that the JMVC reference software for MVC is asserted to have a problem with encoder generation of non-conforming bitstreams; this should be fixed as soon as feasible.
M17603 considers the possibility of defining a potential new profile similar to the current High profile but without "interlaced coding tools" (i.e., specifying frame_mbs_only_flag = 1). The new profile would be targeted to high-end mobile applications and devices. Currently, only two companies impressed a certain level of interest, and the proposal did not include a fully-detailed technical solution. During the discussion it was remarked that if such a new profile is defined it may be desirable to use the constraint_set4_flag for its specification, as it is currently employed for a similar purpose of signaling in the Multiview High Profile.
M17633 reports about an issue where the deblocking filter in SVC implementations may operate differently in previous decoders than it would need to after the recent corrigendum fix in the current draft for Cor.1. To solve this problem, it was decided to put the corrigendum as well as the subsequent new edition on hold and perform a study about viable methods until the July meeting. A report is issued which contains a possible solution approach.
