International organisation for standardisation organisation internationale de normalisation
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- 3MPEG-4 Part 10 AVC
2MPEG-2 VideoNo comments were received from the ballot on the amendment about signalling frame packing arrangement in a quincunx pattern scheme. Consequently, the previous PDAM ballot text was issued for an FDAM ballot without significant changes. Document reviewed:
Document approved:
3MPEG-4 Part 10 AVCTwo corrigenda for AVC conformance (relating to the FRExt and MVC extensions) were progressed to the final corrigendum status (N12727 and N12728). Amd.1 on new SEI messages and additional profiles reached DAM status (N12730), NB comments were responded to as appropriate (N12729), and the text was modified accordingly. Furthermore, the draft for a new Amd.2 for an MVC extension including depth maps was started as PDAM (N12731), and a new WD for another AVC compatible extension with depth maps was produced (N12732). Further information on these is given in section 7 of this report (3DV). During a joint meeting, MPEG’s plans to extend AVC were presented at a joint meeting with VCEG (ITU-T SG16 Question 6) experts, who expressed their interest in ensuring matching development of the twin text of the corresponding ITU-T standard (Rec. ITU-T H.264). Regarding Amd.1, one part (regarding profiles) had already been approved in ITU-T, whereas the part on SEI messages would likely enter the formal ITU-T approval process in January 2013 (i.e. at the same time or after finalization in MPEG). Document M24713 (Canadian NB request regarding level definition in A.3.3(k)) was also presented in the joint meeting with VCEG experts, as the suggested action on this would have an impact on definitions in the twin text and might affect existing products as well. The reported problem seems to have occurred due to the fact that the level had originally been defined without the constraint for minimum number of slices, which was revised in a corrigendum action shortly after. In the meantime between the original and the revised definition, encoders had been implemented which did not obey the multiple-slice constraint, and therefore produce streams that cannot be interpreted by some existing decoders (which use the constraint for the purpose of parallel processing). However, the solution suggested by the CAN NB, adding a new constraint set flag for distinguishing between these two types of operation (single-slice and multiple-slice) would not be viable, as such a flag would also be unknown to existing decoders. Defining a new level above each level currently constrained by A.3.3(k) would also be inconsistent, as it would break the concept of level nesting (wherein a higher level decoder is capable to decode all lower levels) at one point. The only viable solution seems to be the definition of new profile(s), which requires further study. The CAN NB and its members were asked to suggest possible solutions on this as input to the next meeting. Documents reviewed:
Documents approved:
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