Opened 8 weeks ago

Closed 4 weeks ago

#1284 closed defect (fixed)

Confusing language in profile definitions (A.3.1)

Reported by: fbossen Owned by:
Priority: minor Milestone:
Component: spec Version: VVC D10 vE
Keywords: Cc: ksuehring, bbross, XiangLi, fbossen, jvet@…

Description

A.3.1 says:
Conformance of a bitstream to the Main 10 profile is indicated by general_profile_idc being equal to 1.
Conformance of a bitstream to the Main 10 Still Picture profile is indicated by general_profile_idc being equal to 65.

It also says:
– In a bitstream conforming to the Main 10 profile that do not conform to the Main 10 Still Picture profile, general_level_idc and sublayer_level_idc[ i ] for all values of i in the referenced VPS (when available) and in the referenced SPSs shall not be equal to 255 (which indicates level 15.5).

The qualifier "that do not conform to the Main 10 Still Picture profile" is somewhat confusing here, since it seems impossible for it to be false (general_profile_idc may only take one value), although the following note seems to imply otherwise:
NOTE – When the conformance of a bitstream to the Main 10 Still Picture profile is indicated by general_profile_idc being equal to 65, and the indicated level is not level 15.5, the conditions for indication of the conformance of the bitstream to the Main 10 profile are also fulfilled.

What are we trying to say here?

Change history (1)

comment:1 Changed 4 weeks ago by yk

  • Resolution set to fixed
  • Status changed from new to closed

Good catch! The phrase "that do not conform to the Main 10 Still Picture profile" is a carryover from HEVC, wherein the same profile IDC value is used for a main profile and the corresponding still picture profile.

Will be fixed by removing the phrase, in subclauses A.3.1, A.3.2, A.3.3, and A.3.4, in JVET-S2001-vH.

The NOTE is still correct and non-confusing, thus will be kept.

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