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UnitPartitioner.cpp 26.11 KiB
/* The copyright in this software is being made available under the BSD
* License, included below. This software may be subject to other third party
* and contributor rights, including patent rights, and no such rights are
* granted under this license.
*
* Copyright (c) 2010-2018, ITU/ISO/IEC
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions are met:
*
* * Redistributions of source code must retain the above copyright notice,
* this list of conditions and the following disclaimer.
* * Redistributions in binary form must reproduce the above copyright notice,
* this list of conditions and the following disclaimer in the documentation
* and/or other materials provided with the distribution.
* * Neither the name of the ITU/ISO/IEC nor the names of its contributors may
* be used to endorse or promote products derived from this software without
* specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
* AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
* ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS
* BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
* CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
* SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
* INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
* CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
* ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF
* THE POSSIBILITY OF SUCH DAMAGE.
*/
/** \file UnitPartitioner.h
* \brief Provides a class for partitioning management
*/
#include "UnitPartitioner.h"
#include "CodingStructure.h"
#include "Unit.h"
#include "Slice.h"
#include "UnitTools.h"
#include "Picture.h"
PartLevel::PartLevel()
: split ( CU_DONT_SPLIT )
, parts ( )
, idx ( 0u )
, checkdIfImplicit ( false )
, isImplicit ( false )
, implicitSplit ( CU_DONT_SPLIT )
, firstSubPartSplit ( CU_DONT_SPLIT )
, canQtSplit ( true )
{
}
PartLevel::PartLevel( const PartSplit _split, const Partitioning& _parts )
: split ( _split )
, parts ( _parts )
, idx ( 0u )
, checkdIfImplicit ( false )
, isImplicit ( false )
, implicitSplit ( CU_DONT_SPLIT )
, firstSubPartSplit ( CU_DONT_SPLIT )
, canQtSplit ( true )
{
}
PartLevel::PartLevel( const PartSplit _split, Partitioning&& _parts )
: split ( _split )
, parts ( std::forward<Partitioning>( _parts ) )
, idx ( 0u )
, checkdIfImplicit ( false )
, isImplicit ( false )
, implicitSplit ( CU_DONT_SPLIT )
, firstSubPartSplit ( CU_DONT_SPLIT )
, canQtSplit ( true )
{
}
//////////////////////////////////////////////////////////////////////////
// Partitioner class
//////////////////////////////////////////////////////////////////////////
SplitSeries Partitioner::getSplitSeries() const
{
SplitSeries splitSeries = 0;
SplitSeries depth = 0;
for( const auto &level : m_partStack )
{
if( level.split == CTU_LEVEL ) continue;
else splitSeries += static_cast< SplitSeries >( level.split ) << ( depth * SPLIT_DMULT );
depth++;
}
return splitSeries;
}
void Partitioner::setCUData( CodingUnit& cu )
{
cu.depth = currDepth;
cu.btDepth = currBtDepth;
cu.mtDepth = currMtDepth;
cu.qtDepth = currQtDepth;
cu.splitSeries = getSplitSeries();
}
void Partitioner::copyState( const Partitioner& other )
{
m_partStack = other.m_partStack;
currBtDepth = other.currBtDepth;
currQtDepth = other.currQtDepth;
currDepth = other.currDepth;
currMtDepth = other.currMtDepth;
currTrDepth = other.currTrDepth;
currImplicitBtDepth
= other.currImplicitBtDepth;
chType = other.chType;
#ifdef _DEBUG
m_currArea = other.m_currArea;
#endif
}
//////////////////////////////////////////////////////////////////////////
// AdaptiveDepthPartitioner class
//////////////////////////////////////////////////////////////////////////
void AdaptiveDepthPartitioner::setMaxMinDepth( unsigned& minDepth, unsigned& maxDepth, const CodingStructure& cs ) const
{
unsigned stdMinDepth = 0;
unsigned stdMaxDepth = ( g_aucLog2[cs.sps->getCTUSize()] - g_aucLog2[cs.sps->getMinQTSize( cs.slice->getSliceType(), chType )]);
const Position pos = currArea().blocks[chType].pos();
const unsigned curSliceIdx = cs.slice->getIndependentSliceIdx();
#if HEVC_TILES_WPP
const unsigned curTileIdx = cs.picture->tileMap->getTileIdxMap( currArea().lumaPos() );
const CodingUnit* cuLeft = cs.getCURestricted( pos.offset( -1, 0 ), curSliceIdx, curTileIdx, chType );
const CodingUnit* cuBelowLeft = cs.getCURestricted( pos.offset( -1, currArea().blocks[chType].height), curSliceIdx, curTileIdx, chType );
const CodingUnit* cuAbove = cs.getCURestricted( pos.offset( 0, -1 ), curSliceIdx, curTileIdx, chType );
const CodingUnit* cuAboveRight = cs.getCURestricted( pos.offset( currArea().blocks[chType].width, -1 ), curSliceIdx, curTileIdx, chType );
#else
const CodingUnit* cuLeft = cs.getCURestricted( pos.offset( -1, 0 ), curSliceIdx, chType );
const CodingUnit* cuBelowLeft = cs.getCURestricted( pos.offset( -1, currArea().blocks[chType].height), curSliceIdx, chType );
const CodingUnit* cuAbove = cs.getCURestricted( pos.offset( 0, -1 ), curSliceIdx, chType );
const CodingUnit* cuAboveRight = cs.getCURestricted( pos.offset( currArea().blocks[chType].width, -1 ), curSliceIdx, chType );
#endif
minDepth = stdMaxDepth;
maxDepth = stdMinDepth;
if( cuLeft )
{
minDepth = std::min<unsigned>( minDepth, cuLeft->qtDepth );
maxDepth = std::max<unsigned>( maxDepth, cuLeft->qtDepth );
}
else
{
minDepth = stdMinDepth;
maxDepth = stdMaxDepth;
}
if( cuBelowLeft )
{
minDepth = std::min<unsigned>( minDepth, cuBelowLeft->qtDepth );
maxDepth = std::max<unsigned>( maxDepth, cuBelowLeft->qtDepth );
}
else
{
minDepth = stdMinDepth;
maxDepth = stdMaxDepth;
}
if( cuAbove )
{
minDepth = std::min<unsigned>( minDepth, cuAbove->qtDepth );
maxDepth = std::max<unsigned>( maxDepth, cuAbove->qtDepth );
}
else
{
minDepth = stdMinDepth;
maxDepth = stdMaxDepth;
}
if( cuAboveRight )
{
minDepth = std::min<unsigned>( minDepth, cuAboveRight->qtDepth );
maxDepth = std::max<unsigned>( maxDepth, cuAboveRight->qtDepth );
}
else
{
minDepth = stdMinDepth;
maxDepth = stdMaxDepth;
}
minDepth = ( minDepth >= 1 ? minDepth - 1 : 0 );
maxDepth = std::min<unsigned>( stdMaxDepth, maxDepth + 1 );
}
//////////////////////////////////////////////////////////////////////////
//////////////////////////////////////////////////////////////////////////
//////////////////////////////////////////////////////////////////////////
//////////////////////////////////////////////////////////////////////////
//////////////////////////////////////////////////////////////////////////
//////////////////////////////////////////////////////////////////////////
// QTBTPartitioner
////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////
//////////////////////////////////////////////////////////////////////////
//////////////////////////////////////////////////////////////////////////
//////////////////////////////////////////////////////////////////////////
//////////////////////////////////////////////////////////////////////////
void QTBTPartitioner::initCtu( const UnitArea& ctuArea, const ChannelType _chType, const Slice& slice )
{
#if _DEBUG
m_currArea = ctuArea;
#endif
currDepth = 0;
currTrDepth = 0;
currBtDepth = 0;
currMtDepth = 0;
currQtDepth = 0;
currImplicitBtDepth = 0;
chType = _chType;
m_partStack.clear();
m_partStack.push_back( PartLevel( CTU_LEVEL, Partitioning{ ctuArea } ) );
}
void QTBTPartitioner::splitCurrArea( const PartSplit split, const CodingStructure& cs )
{
CHECKD( !canSplit( split, cs ), "Trying to apply a prohibited split!" );
bool isImplicit = isSplitImplicit( split, cs );
bool canQtSplit = canSplit( CU_QUAD_SPLIT, cs );
switch( split )
{
case CU_QUAD_SPLIT:
m_partStack.push_back( PartLevel( split, PartitionerImpl::getCUSubPartitions( currArea(), cs ) ) );
break;
case CU_HORZ_SPLIT:
case CU_VERT_SPLIT:
m_partStack.push_back( PartLevel( split, PartitionerImpl::getCUSubPartitions( currArea(), cs, split ) ) );
break;
case CU_TRIH_SPLIT:
case CU_TRIV_SPLIT:
CHECK( ( cs.sps->getSpsNext().getMTTMode() & 1 ) != 1, "Triple splits are not allowed" );
m_partStack.push_back( PartLevel( split, PartitionerImpl::getCUSubPartitions( currArea(), cs, split ) ) );
break;
case TU_MAX_TR_SPLIT:
m_partStack.push_back( PartLevel( split, PartitionerImpl::getMaxTuTiling( currArea(), cs ) ) );
break;
default:
THROW( "Unknown split mode" );
break;
}
currDepth++;
#if _DEBUG
m_currArea = m_partStack.back().parts.front();
#endif
if( split == TU_MAX_TR_SPLIT )
{
currTrDepth++;
}
else
{
currTrDepth = 0;
}
if( split == CU_HORZ_SPLIT || split == CU_VERT_SPLIT || split == CU_TRIH_SPLIT || split == CU_TRIV_SPLIT )
{
currBtDepth++;
if( isImplicit ) currImplicitBtDepth++; currMtDepth++;
if( split == CU_TRIH_SPLIT || split == CU_TRIV_SPLIT )
{
// first and last part of triple split are equivalent to double bt split
currBtDepth++;
}
m_partStack.back().canQtSplit = canQtSplit;
}
else if( split == CU_QUAD_SPLIT )
{
CHECK( currBtDepth > 0, "Cannot split a non-square area other than with a binary split" );
CHECK( currMtDepth > 0, "Cannot split a non-square area other than with a binary split" );
currMtDepth = 0;
currBtDepth = 0;
currQtDepth++;
}
}
bool QTBTPartitioner::canSplit( const PartSplit split, const CodingStructure &cs )
{
const PartSplit implicitSplit = getImplicitSplit( cs );
// the minimal and maximal sizes are given in luma samples
const CompArea area = currArea().Y();
const unsigned maxBTD = cs.pcv->getMaxBtDepth( *cs.slice, chType ) + currImplicitBtDepth;
const unsigned maxBtSize = cs.pcv->getMaxBtSize( *cs.slice, chType );
const unsigned minBtSize = cs.pcv->getMinBtSize( *cs.slice, chType );
const unsigned maxTtSize = cs.pcv->getMaxTtSize( *cs.slice, chType );
const unsigned minTtSize = cs.pcv->getMinTtSize( *cs.slice, chType );
const unsigned maxTrSize = cs.sps->getMaxTrSize();
const PartSplit lastSplit = m_partStack.back().split;
const PartSplit parlSplit = lastSplit == CU_TRIH_SPLIT ? CU_HORZ_SPLIT : CU_VERT_SPLIT;
if( isNonLog2BlockSize( currArea().Y() ) )
{
return false;
}
switch( split )
{
case CTU_LEVEL:
THROW( "Checking if top level split is possible" );
return true;
break;
case TU_MAX_TR_SPLIT:
return area.width > maxTrSize || area.height > maxTrSize;
break;
case CU_QUAD_SPLIT:
{
// don't allow QT-splitting below a BT split
PartSplit lastSplit = m_partStack.back().split;
if( lastSplit != CTU_LEVEL && lastSplit != CU_QUAD_SPLIT ) return false;
unsigned minQtSize = cs.pcv->getMinQtSize( *cs.slice, chType );
if( currArea().lwidth() <= minQtSize || currArea().lheight() <= minQtSize ) return false;
// allowing QT split even if a BT split is implied
if( implicitSplit != CU_DONT_SPLIT ) return true;
return true;
}
break;
case CU_DONT_SPLIT:
return implicitSplit == CU_DONT_SPLIT;
break;
// general check for BT split, specific checks are done in a separate switch
case CU_HORZ_SPLIT: case CU_VERT_SPLIT:
{
if( ( lastSplit == CU_TRIH_SPLIT || lastSplit == CU_TRIV_SPLIT ) && currPartIdx() == 1 && split == parlSplit )
{
return false;
}
if (CS::isDualITree(cs) && (area.width > 64 || area.height > 64))
{
return false;
}
}
case CU_TRIH_SPLIT:
case CU_TRIV_SPLIT:
{
if (CS::isDualITree(cs) && (area.width > 64 || area.height > 64))
{
return false;
}
}
if( implicitSplit == split ) return true;
if( implicitSplit != CU_DONT_SPLIT && implicitSplit != split ) return false;
case CU_MT_SPLIT:
case CU_BT_SPLIT:
{
if( currMtDepth >= maxBTD ) return false;
if( ( area.width <= minBtSize && area.height <= minBtSize )
&& ( ( area.width <= minTtSize && area.height <= minTtSize ) || cs.sps->getSpsNext().getMTTMode() == 0 ) ) return false;
if( ( area.width > maxBtSize || area.height > maxBtSize )
&& ( ( area.width > maxTtSize || area.height > maxTtSize ) || cs.sps->getSpsNext().getMTTMode() == 0 ) ) return false;
if (CS::isDualITree(cs) && (area.width > 64 || area.height > 64))
{
return false;
}
}
break;
default:
THROW( "Unknown split mode" );
return false;
break;
}
// specific check for BT splits
switch( split )
{
case CU_HORZ_SPLIT:
if( area.height <= minBtSize || area.height > maxBtSize ) return false;
if( area.width > MAX_TU_SIZE_FOR_PROFILE && area.height <= MAX_TU_SIZE_FOR_PROFILE ) return false;
break;
case CU_VERT_SPLIT:
if( area.width <= minBtSize || area.width > maxBtSize ) return false;
if( area.width <= MAX_TU_SIZE_FOR_PROFILE && area.height > MAX_TU_SIZE_FOR_PROFILE ) return false;
break;
case CU_TRIH_SPLIT:
if( ( cs.sps->getSpsNext().getMTTMode() & 1 ) != 1 ) return false;
if( area.height <= 2 * minTtSize || area.height > maxTtSize || area.width > maxTtSize) return false;
if( area.width > MAX_TU_SIZE_FOR_PROFILE || area.height > MAX_TU_SIZE_FOR_PROFILE ) return false;
break;
case CU_TRIV_SPLIT:
if( ( cs.sps->getSpsNext().getMTTMode() & 1 ) != 1 ) return false;
if( area.width <= 2 * minTtSize || area.width > maxTtSize || area.height > maxTtSize) return false;
if( area.width > MAX_TU_SIZE_FOR_PROFILE || area.height > MAX_TU_SIZE_FOR_PROFILE ) return false;
break;
default:
break;
}
return true;
}
bool QTBTPartitioner::isSplitImplicit( const PartSplit split, const CodingStructure &cs ){
return split == getImplicitSplit( cs );
}
PartSplit QTBTPartitioner::getImplicitSplit( const CodingStructure &cs )
{
if( m_partStack.back().checkdIfImplicit )
{
return m_partStack.back().implicitSplit;
}
PartSplit split = CU_DONT_SPLIT;
if( split == CU_DONT_SPLIT )
{
const bool isBlInPic = cs.picture->Y().contains( currArea().Y().bottomLeft() );
const bool isTrInPic = cs.picture->Y().contains( currArea().Y().topRight() );
const CompArea& area = currArea().Y();
const unsigned maxBtSize = cs.pcv->getMaxBtSize( *cs.slice, chType );
const bool isBtAllowed = area.width <= maxBtSize && area.height <= maxBtSize;
const unsigned minQtSize = cs.pcv->getMinQtSize( *cs.slice, chType );
const bool isQtAllowed = area.width > minQtSize && area.height > minQtSize && currBtDepth == 0;
if( !isBlInPic && !isTrInPic && isQtAllowed )
{
split = CU_QUAD_SPLIT;
}
else if( !isBlInPic && isBtAllowed )
{
split = CU_HORZ_SPLIT;
}
else if( !isTrInPic && isBtAllowed )
{
split = CU_VERT_SPLIT;
}
else if( !isBlInPic || !isTrInPic )
{
split = CU_QUAD_SPLIT;
}
if (CS::isDualITree(cs) && (currArea().Y().width > 64 || currArea().Y().height > 64))
{
split = CU_QUAD_SPLIT;
}
}
m_partStack.back().checkdIfImplicit = true;
m_partStack.back().isImplicit = split != CU_DONT_SPLIT;
m_partStack.back().implicitSplit = split;
return split;
}
void QTBTPartitioner::exitCurrSplit()
{
PartSplit currSplit = m_partStack.back().split;
unsigned currIdx = m_partStack.back().idx;
m_partStack.pop_back();
CHECK( currDepth == 0, "depth is '0', although a split was performed" );
currDepth--;
#if _DEBUG
m_currArea = m_partStack.back().parts[m_partStack.back().idx];
#endif
if( currSplit == CU_HORZ_SPLIT || currSplit == CU_VERT_SPLIT || currSplit == CU_TRIH_SPLIT || currSplit == CU_TRIV_SPLIT )
{
CHECK( !m_partStack.back().checkdIfImplicit, "Didn't check if the current split is implicit" );
CHECK( currBtDepth == 0, "BT depth is '0', athough a BT split was performed" ); CHECK( currMtDepth == 0, "MT depth is '0', athough a BT split was performed" );
currMtDepth--;
if( m_partStack.back().isImplicit ) currImplicitBtDepth--;
currBtDepth--;
if( ( currSplit == CU_TRIH_SPLIT || currSplit == CU_TRIV_SPLIT ) && currIdx != 1 )
{
CHECK( currBtDepth == 0, "BT depth is '0', athough a TT split was performed" );
currBtDepth--;
}
}
else if( currSplit == TU_MAX_TR_SPLIT )
{
CHECK( currTrDepth == 0, "TR depth is '0', although a TU split was performed" );
currTrDepth--;
}
else
{
CHECK( currTrDepth > 0, "RQT found with QTBT partitioner" );
CHECK( currQtDepth == 0, "QT depth is '0', although a QT split was performed" );
currQtDepth--;
}
}
bool QTBTPartitioner::nextPart( const CodingStructure &cs, bool autoPop /*= false*/ )
{
const Position &prevPos = currArea().blocks[chType].pos();
unsigned currIdx = ++m_partStack.back().idx;
m_partStack.back().checkdIfImplicit = false;
m_partStack.back().isImplicit = false;
if( currIdx == 1 )
{
const CodingUnit* prevCU = cs.getCU( prevPos, chType );
m_partStack.back().firstSubPartSplit = prevCU ? CU::getSplitAtDepth( *prevCU, currDepth ) : CU_DONT_SPLIT;
}
if( currIdx < m_partStack.back().parts.size() )
{
if( m_partStack.back().split == CU_TRIH_SPLIT || m_partStack.back().split == CU_TRIV_SPLIT )
{
// adapt the current bt depth
if( currIdx == 1 ) currBtDepth--;
else currBtDepth++;
}
#if _DEBUG
m_currArea = m_partStack.back().parts[currIdx];
#endif
return true;
}
else
{
if( autoPop ) exitCurrSplit();
return false;
}
}
bool QTBTPartitioner::hasNextPart()
{
return ( ( m_partStack.back().idx + 1 ) < m_partStack.back().parts.size() );
}
//////////////////////////////////////////////////////////////////////////
// PartitionerFactory
//////////////////////////////////////////////////////////////////////////
Partitioner* PartitionerFactory::get( const Slice& slice )
{
return new QTBTPartitioner;
}
//////////////////////////////////////////////////////////////////////////
// Partitioner methods describing the actual partitioning logic
//////////////////////////////////////////////////////////////////////////
Partitioning PartitionerImpl::getCUSubPartitions( const UnitArea &cuArea, const CodingStructure &cs, const PartSplit _splitType /*= CU_QUAD_SPLIT*/ )
{
const PartSplit splitType = _splitType;
if( splitType == CU_QUAD_SPLIT )
{
if( !cs.pcv->noChroma2x2 )
{
Partitioning sub;
sub.resize( 4, cuArea );
for( uint32_t i = 0; i < 4; i++ )
{
for( auto &blk : sub[i].blocks )
{
blk.height >>= 1;
blk.width >>= 1;
if( i >= 2 ) blk.y += blk.height;
if( i & 1 ) blk.x += blk.width;
}
CHECK( sub[i].lumaSize().height < MIN_TU_SIZE, "the split causes the block to be smaller than the minimal TU size" );
}
return sub;
}
else
{
const uint32_t minCUSize = ( cs.sps->getMaxCUWidth() >> cs.sps->getMaxCodingDepth() );
bool canSplit = cuArea.lumaSize().width > minCUSize && cuArea.lumaSize().height > minCUSize;
Partitioning ret;
if( cs.slice->getSliceType() == I_SLICE )
{
canSplit &= cuArea.lumaSize().width > cs.pcv->minCUWidth && cuArea.lumaSize().height > cs.pcv->minCUHeight;
}
if( canSplit )
{
ret.resize( 4 );
if( cuArea.chromaFormat == CHROMA_400 )
{
CompArea blkY = cuArea.Y();
blkY.width >>= 1;
blkY.height >>= 1;
ret[0] = UnitArea( cuArea.chromaFormat, blkY );
blkY.x += blkY.width;
ret[1] = UnitArea( cuArea.chromaFormat, blkY );
blkY.x -= blkY.width;
blkY.y += blkY.height;
ret[2] = UnitArea( cuArea.chromaFormat, blkY );
blkY.x += blkY.width;
ret[3] = UnitArea( cuArea.chromaFormat, blkY );
}
else
{
for( uint32_t i = 0; i < 4; i++ ) {
ret[i] = cuArea;
CompArea &blkY = ret[i].Y();
CompArea &blkCb = ret[i].Cb();
CompArea &blkCr = ret[i].Cr();
blkY.width /= 2;
blkY.height /= 2;
// TODO: get those params from SPS
if( blkCb.width > 4 )
{
blkCb.width /= 2;
blkCb.height /= 2;
blkCr.width /= 2;
blkCr.height /= 2;
}
else if( i > 0 )
{
blkCb = CompArea();
blkCr = CompArea();
}
if( ( i & 1 ) == 1 )
{
blkY.x += blkY .width;
blkCb.x += blkCb.width;
blkCr.x += blkCr.width;
}
if( i > 1 )
{
blkY.y += blkY .height;
blkCb.y += blkCb.height;
blkCr.y += blkCr.height;
}
}
}
}
return ret;
}
}
else if( splitType == CU_HORZ_SPLIT )
{
Partitioning sub;
sub.resize(2, cuArea);
for (uint32_t i = 0; i < 2; i++)
{
for (auto &blk : sub[i].blocks)
{
blk.height >>= 1;
if (i == 1) blk.y += blk.height;
}
CHECK(sub[i].lumaSize().height < MIN_TU_SIZE, "the cs split causes the block to be smaller than the minimal TU size");
}
return sub;
}
else if( splitType == CU_VERT_SPLIT )
{
Partitioning sub;
sub.resize( 2, cuArea );
for( uint32_t i = 0; i < 2; i++ ) {
for( auto &blk : sub[i].blocks )
{
blk.width >>= 1;
if( i == 1 ) blk.x += blk.width;
}
CHECK( sub[i].lumaSize().width < MIN_TU_SIZE, "the split causes the block to be smaller than the minimal TU size" );
}
return sub;
}
else if( splitType == CU_TRIH_SPLIT )
{
Partitioning sub;
sub.resize( 3, cuArea );
for( int i = 0; i < 3; i++ )
{
for( auto &blk : sub[i].blocks )
{
blk.height >>= 1;
if( ( i + 1 ) & 1 ) blk.height >>= 1;
if( i == 1 ) blk.y += blk.height / 2;
if( i == 2 ) blk.y += 3 * blk.height;
}
CHECK( sub[i].lumaSize().height < MIN_TU_SIZE, "the cs split causes the block to be smaller than the minimal TU size" );
}
return sub;
}
else if( splitType == CU_TRIV_SPLIT )
{
Partitioning sub;
sub.resize( 3, cuArea );
for( int i = 0; i < 3; i++ )
{
for( auto &blk : sub[i].blocks )
{
blk.width >>= 1;
if( ( i + 1 ) & 1 ) blk.width >>= 1;
if( i == 1 ) blk.x += blk.width / 2;
if( i == 2 ) blk.x += 3 * blk.width;
}
CHECK( sub[i].lumaSize().width < MIN_TU_SIZE, "the cs split causes the block to be smaller than the minimal TU size" );
}
return sub;
}
else
{
THROW( "Unknown CU sub-partitioning" );
return Partitioning();
}
}
static const int g_maxRtGridSize = 3;
static const int g_zScanToX[1 << ( g_maxRtGridSize << 1 )] =
{
0, 1, 0, 1, 2, 3, 2, 3,
0, 1, 0, 1, 2, 3, 2, 3,
4, 5, 4, 5, 6, 7, 6, 7,
4, 5, 4, 5, 6, 7, 6, 7, 0, 1, 0, 1, 2, 3, 2, 3,
0, 1, 0, 1, 2, 3, 2, 3,
4, 5, 4, 5, 6, 7, 6, 7,
4, 5, 4, 5, 6, 7, 6, 7,
};
static const int g_zScanToY[1 << ( g_maxRtGridSize << 1 )] =
{
0, 0, 1, 1, 0, 0, 1, 1,
2, 2, 3, 3, 2, 2, 3, 3,
0, 0, 1, 1, 0, 0, 1, 1,
2, 2, 3, 3, 2, 2, 3, 3,
4, 4, 5, 5, 4, 4, 5, 5,
6, 6, 7, 7, 6, 5, 7, 7,
4, 4, 5, 5, 4, 4, 5, 5,
6, 6, 7, 7, 6, 5, 7, 7,
};
static const int g_rsScanToZ[1 << ( g_maxRtGridSize << 1 )] =
{
0, 1, 4, 5, 16, 17, 20, 21,
2, 3, 6, 7, 18, 19, 22, 23,
8, 9, 12, 13, 24, 25, 28, 29,
10, 11, 14, 15, 26, 27, 30, 31,
32, 33, 36, 37, 48, 49, 52, 53,
34, 35, 38, 39, 50, 51, 54, 55,
40, 41, 44, 45, 56, 57, 60, 61,
42, 43, 46, 47, 58, 59, 62, 63,
};
Partitioning PartitionerImpl::getMaxTuTiling( const UnitArea &cuArea, const CodingStructure &cs )
{
static_assert( MAX_LOG2_DIFF_CU_TR_SIZE <= g_maxRtGridSize, "Z-scan tables are only provided for MAX_LOG2_DIFF_CU_TR_SIZE for up to 3 (8x8 tiling)!" );
const CompArea area = cuArea.Y().valid() ? cuArea.Y() : cuArea.Cb();
const int maxTrSize = cs.sps->getMaxTrSize() >> ( isLuma( area.compID ) ? 0 : 1 );
const int numTilesH = std::max<int>( 1, area.width / maxTrSize );
const int numTilesV = std::max<int>( 1, area.height / maxTrSize );
const int numTiles = numTilesH * numTilesV;
CHECK( numTiles > MAX_CU_TILING_PARTITIONS, "CU partitioning requires more partitions than available" );
Partitioning ret;
ret.resize( numTiles, cuArea );
for( int i = 0; i < numTiles; i++ )
{
const int rsy = i / numTilesH;
const int rsx = i % numTilesH;
const int x = g_zScanToX[g_rsScanToZ[( rsy << g_maxRtGridSize ) + rsx]];
const int y = g_zScanToY[g_rsScanToZ[( rsy << g_maxRtGridSize ) + rsx]];
UnitArea& tile = ret[i];
for( CompArea &comp : tile.blocks )
{
if( !comp.valid() ) continue;
comp.width /= numTilesH;
comp.height /= numTilesV;
comp.x += comp.width * x;
comp.y += comp.height * y;
}
}
return ret;
}