Opened 8 years ago

Closed 7 years ago

#1231 closed defect (fixed)

refMatrixId can become negative

Reported by: jackh Owned by:
Priority: minor Milestone: RExt D6
Component: RExt text Version: RExt D5 (O1005) v3
Keywords: Cc: davidf, joel, teruhiko, jct-vc@…

Description

Equation 7-35 states:

refMatrixId = matrixId − scaling_list_pred_matrix_id_delta[ sizeId ][ matrixId ] * ( sizeId == 3 ? 3 : 1 )

and the specification constrains scaling_list_pred_matrix_id_delta as follows:

The value of scaling_list_pred_matrix_id_delta[ sizeId ][ matrixId ] shall be in the range of 0 to maxMatrixId, inclusive.

The combination of these two allows refMatrixId to become negative. Perhaps the constraint on scaling_list_pred_matrix_id_delta should read:

The value of scaling_list_pred_matrix_id_delta[ sizeId ][ matrixId ] shall be in the range of 0 to sizeId==3?(matrixId/3):matrixId, inclusive.

Change History (4)

comment:1 Changed 8 years ago by DefaultCC Plugin

  • Cc davidf joel teruhiko jct-vc@… added

comment:2 Changed 8 years ago by davidf

  • Milestone set to RExt D6
  • Resolution set to fixed
  • Status changed from new to closed

Confirmed.
Removed maxMatrixId, replaced constraint with a more verbose version.

comment:3 Changed 8 years ago by jackh

  • Resolution fixed deleted
  • Status changed from closed to reopened

I think this problem still exists in the updated spec when sizeId==3 and matrixId<3, as scaling_list_pred_matrix_id_delta can currently still be 1 in this case, which would again make refMatrixId negative. I think scaling_list_pred_matrix_id_delta should be constrained to be zero in this case.

comment:4 Changed 7 years ago by davidf

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

The text (P1005_v4) has been updated with:

Otherwise (sizeId is equal to 3), the value of
scaling_list_pred_matrix_id_delta[ sizeId ][ matrixId ]
shall be in the range of 0 to matrixId / 3, inclusive

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  • David Flynn(Subscriber, Participant)
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  • Joel(Subscriber)
  • karl.sharman@…(Always)
  • Karsten Suehring(Always)
  • Teruhiko Suzuki(Subscriber)