JVET-Y0237 Integrated specification text for JVET-Y0049 and JVET-Y0190 [J. Gan (OPPO), Y.-K. Wang (Bytedance)] [late]
Following presentation of input contributions JVET-Y0005, JVET-Y0049, and JVET-Y0190, it was asserted that several bugs exist in the VVC version 2 specification relating to the general constraints information syntax, two of which were the cause of errors in conformance testing reported by JVET-Y0005. Relevant experts were asked to develop an integrated text to fix the bugs. Although consensus was reached on the majority of the text, differences of opinion still remain on one section of the text, namely the semantics for gci_num_additional_bits. The differences have been captured in three options.
It is proposed to adopt the integrated text for one of options A, B or C. An associated software patch for the chosen option will be provided for VTM 16.0.
Option A would also allow values 1..5 in future, which is undesirable
Option B requires a decoder to ignore the values of GCI flags, in case that a value 1..5 would appear, and values >6.
Option C requires a a decoder to ignore the values of GCI flags, in case that a value >6 would appear (as values 1..5 could never happen). If values 1..5 would appear, this would be a non-conforming bitstream.
It is agreed that option C is the most logical solution.
Decision: Adopt JVET-0237 option C.