Opened 6 years ago
Closed 6 years ago
#282 closed defect (fixed)
Issue in tb(v) decoding description
Reported by: | forayr | Owned by: | |
---|---|---|---|
Priority: | minor | Milestone: | |
Component: | spec | Version: | VVC D5 v6 |
Keywords: | Cc: | ksuehring, bbross, XiangLi, fbossen, jvet@β¦ |
Description
In 9.4 Parsing process for truncated binary codes, the derivation of variable th is incomplete. For all maxVal below 256, the calculation in the specification return th = 7, which is not the case in the vtm.
In the spec:
thVal = 1 << 8 th = 8 while( thVal <= maxVal ) { th++ thVal <<= 1 } thββ
In vtm:
int uiThresh; if( uiMaxSymbol > 256 ) { int uiThreshVal = 1 << 8; uiThresh = 8; while( uiThreshVal <= uiMaxSymbol ) { uiThresh++; uiThreshVal <<= 1; } uiThresh--; } else { uiThresh = g_tbMax[uiMaxSymbol]; }
By the way, in the line 'b = n - val', 'n' is not defined in the spec and should be replaced by maxVal.
Change history (2)
comment:1 Changed 6 years ago by nanhu
comment:2 Changed 6 years ago by bbross
- Resolution set to fixed
- Status changed from new to closed
Fixed in D5 v7
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For the variable 'th',
A fix could be:
In the line 'b = n - val', I agree that 'n' should be replaced by maxVal.