Opened 11 years ago

Closed 11 years ago

Last modified 11 years ago

#892 closed defect (fixed)

QP inheritance problem at bottom of non-CTU-multiple height images

Reported by: gordon Owned by:
Priority: minor Milestone: HM-9.2
Component: HM Version: HM-9.1
Keywords: QP, dependent slice, intersect, edge Cc: fbossen, ksuehring, davidf, jct-vc@…


Using a variable QP, a CTU size of 64 and class D images (ie, the bottom CTU row does not fully intersect the image being coded), there is a QP inheritance problem on the last row if a dependent slice starts later than the left-most CTU. There is a decoder mismatch during decoding, as a wrong QP may be used.

This is due to the fact that the data in CTUs corresponding to an area outside of the image are not correctly initialized in the decoder when a slice (dependent or independent) is terminated. These data are later used, however, when searching for a 'last QP coded' from a dependent-slice CTU directly to the right.

The attached patch prevents a 'break' occuring during traversal of the CTU when 'isLast' is seen, and correctly completes CTU initialisation when 'isLast' is true.

Possibly related to ticket #671, but this issue was not seen with HM 9.0.

Attachments (1)

qpinheritancefix.patch (1.1 KB) - added by gordon 11 years ago.

Download all attachments as: .zip

Change History (4)

comment:1 Changed 11 years ago by DefaultCC Plugin

  • Cc fbossen ksuehring davidf jct-vc@… added

Changed 11 years ago by gordon

comment:2 Changed 11 years ago by fbossen

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

Fixed in r3190

comment:3 Changed 11 years ago by fbossen

  • Milestone set to HM-9.2
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