Opened 8 years ago

Closed 7 years ago

#80 closed mismatch (fixed)

Inconsistency of signaling condition for depth_dc_sign_flag between WD and HTM-12.0

Reported by: tsukuba.takeshi Owned by: tech
Priority: minor Component: 3D-HEVC text
Version: Keywords:
Cc: tech, jct-3v@…

Description

In I.7.3.8.5.2 Coding unit extension syntax, depth_dc_sign_flag is signaled when depth_dc_abs[x0+k][y0+j][i] is greater than 0 as follows:

dcNumSeg = DmmFlag[ x0 + k ][ y0 + j ] ? 2 : 1
if( depth_dc_flag[ x0 + k ][ y0 + j ] )

for( i = 0; i < dcNumSeg; i ++ ) {

depth_dc_abs[x0+k][y0+j][i]
if(depth_dc_abs[x0+k][y0+j][i] >0)

depth_dc_sign_flag[x0+k][y0+j][i]

}

On the other hand,in HTM-12.0, it is signaled when the absolute value of DcOffset is greater than 0 as follows:

Void TDecSbac::xParseDimDeltaDC( Pel& rValDeltaDC, UInt uiNumSeg )
{

UInt absValDeltaDC = 0;
xReadExGolombLevel( absValDeltaDC, m_cDdcDataSCModel.get(0, 0, 0) );
rValDeltaDC = (Pel)absValDeltaDC + ( uiNumSeg > 1 ? 0 : 1 );
...
if( rValDeltaDC != 0 )
{

UInt uiSign;
m_pcTDecBinIf->decodeBinEP( uiSign );

}
...

}

Signaling condition for depth_dc_sign_flag in WD should be aligned with HTM-12.0 as follows:

for example

dcNumSeg = DmmFlag[ x0 + k ][ y0 + j ] ? 2 : 1
if( depth_dc_flag[ x0 + k ][ y0 + j ] )

for( i = 0; i < dcNumSeg; i ++ ) {

depth_dc_abs[x0+k][y0+j][i]
if((depth_dc_abs[x0+k][y0+j][i] - dcNumseg + 2) >0)
or
if((depth_dc_abs[x0+k][y0+j][i] + (dcNumseg > 1 ? 0 : 1 ) >0)

depth_dc_sign_flag[x0+k][y0+j][i]

}

Change history (3)

comment:1 Changed 8 years ago by DefaultCC Plugin

  • Cc tech jct-3v@… added

comment:2 Changed 8 years ago by tech

I think this mismatch was introduced when unifying SDC and DMM dc offsets (JCT3V-F0132). Maybe the proponents of F0132 can share their opinion, if text or software need to be fixed.

comment:3 Changed 7 years ago by tech

  • Resolution set to fixed
  • Status changed from new to closed
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  • Gerhard Tech(Owner, Subscriber, Participant, Always)
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  • Takeshi Tsukuba(Reporter)