Opened 12 years ago Closed 12 years ago #948 closed defect (fixed)wavefront availableFlagT derivation when PicWidthInCtbsY is 2 and pic_width_in_luma_samples%CtbSizeY is not zero
Description
According to Text
( xT, yT ) = ( x0 + 2 << Log2CtbSizeY − 1, y0 − 1 ) (9-3)
when PicWidthInCtbsY is 2 and pic_width_in_luma_samples%CtbSizeY is not zero, (xT, yT) will be out of picture boundary, and availableFlagT should be FALSE.
But in HM-9.1, it only checks availability of top-right coding tree block, and availableFlagT will be TRUE.
This discrepancy should be fixed in HM or Text Change History (2)comment:1 Changed 12 years ago by bbross
comment:2 Changed 12 years ago by bbross
Fixed in JCTVC-L0030_v3. Note: See
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This is a draft issue and incomplete CTBs should be considered as available while the ctx variable should always be copied from the last CU in the second CTU in a row, independent of whether the associated luma CTB is complete or not.
In the draft, the derivation of location (xT, yT) should be changed to represent to top-left sample of the luma CTB for availability check and Figure 9-2 should be updated accordingly:
( xT, yT ) = ( x0 + 1 << Log2CtbSizeY, y0 + 1 << Log2CtbSizeY )