public void Read(BitReader bitReader)
{
FirstMBInSlice = bitReader.DecodeUnsignedExpGolomb();
SliceType = ReadSliceType(bitReader);
PICParameterSetID = bitReader.DecodeUnsignedExpGolomb();
FrameNum = bitReader.GetUIntFromNBits(_frameNumBits);
if (!_sps.FrameMBSOnly)
{
FieldPicFlag = bitReader.GetNextBit();
if (FieldPicFlag)
{
BottomFieldFlag = bitReader.GetNextBit();
}
}
if (_nalu.NALUType == NALUnitType.IDRSlice)
{
IDRPictureID = bitReader.DecodeUnsignedExpGolomb();
PrevRefFrameNum = 0;
}
if (_sps.gPicOrderCntType == 0)
{
PictureOrderCountLSB = bitReader.GetUIntFromNBits((ushort)(_sps.gMaxPicOrderCntLsbMinus4 + 4u));
if (_pps.PICOrderPresentFlag && !FieldPicFlag)
{
DeltaPictureOrderCountBottom = bitReader.DecodeSignedExpGolomb();
}
}
if ((_sps.gPicOrderCntType == 1) && !_sps.DeltaPicOrderAlwaysZero)
{
DeltaPictureOrderCount = new int[2];
DeltaPictureOrderCount[0] = bitReader.DecodeSignedExpGolomb();
if (_pps.PICOrderPresentFlag && !FieldPicFlag)
{
DeltaPictureOrderCount[1] = bitReader.DecodeSignedExpGolomb();
}
}
if (_pps.RedundantPICCountPresentFlag)
{
RedundantPictureCount = bitReader.DecodeUnsignedExpGolomb();
}
if (SliceType == SliceTypes.B)
{
DirectSpatialMVPredFlag = bitReader.GetNextBit();
}
if ((SliceType == SliceTypes.P) || (SliceType == SliceTypes.SP) || (SliceType == SliceTypes.B))
{
NumRefIdxActiveOverrideFlag = bitReader.GetNextBit();
if (NumRefIdxActiveOverrideFlag)
{
NumRefIdx10ActiveMinus1 = bitReader.DecodeUnsignedExpGolomb();
if (SliceType == SliceTypes.B)
{
NumRefIdx11ActiveMinus1 = bitReader.DecodeUnsignedExpGolomb();
}
}
}
ReferencePictureListReordering(bitReader);
if ((_pps.WeightedPredFlag && ((SliceType == SliceTypes.P) || (SliceType == SliceTypes.SP))) ||
((_pps.WeightedBiPredIDC == 1) && (SliceType == SliceTypes.B)))
{
PredictionWeightTable(bitReader);
}
if (_nalu.NALRefIDC != 0)
{
DecodedReferencePictureMarking(bitReader);
}
if (_pps.EntropyCodingModeFlag && (SliceType != SliceTypes.I) && (SliceType != SliceTypes.SI))
{
uint initIdc = bitReader.DecodeUnsignedExpGolomb();
if (initIdc < 4)
{
CABACInitIDC = (byte)initIdc;
}
else
{
throw new Exception("SliceHeader: bad CABACInitIDC");
}
}
SliceQPDelta = bitReader.DecodeSignedExpGolomb();
SliceQPy = 26 + _pps.PICInitQPMinus26 + SliceQPDelta;
if ((SliceType == SliceTypes.SP) || (SliceType == SliceTypes.SI))
{
if (SliceType == SliceTypes.SP)
{
SP4SwitchFlag = bitReader.GetNextBit();
}
SliceQSDelta = bitReader.DecodeSignedExpGolomb();
SliceQSy = 26 + _pps.PICInitQSMinus26 + SliceQSDelta;
}
if (_pps.DeblockingFilterControlPresentFlag)
{
DisableDeblockingFilterIDC = bitReader.DecodeUnsignedExpGolomb();
if (DisableDeblockingFilterIDC != 1)
{
SliceAlphaC0OffsetDiv2 = bitReader.DecodeSignedExpGolomb();
SliceBetaOffsetDiv2 = bitReader.DecodeSignedExpGolomb();
}
}
if ((_pps.NumSliceGroupsMinus1 > 0) && (_pps.SliceGroupMapType >= 3) && (_pps.SliceGroupMapType <= 5))
{
SliceGroupChangeCycle = bitReader.GetUIntFromNBits(BitReader.CalcBitsNeededToRepresent(_pps.NumSliceGroupsMinus1 + 1));
}
// once the header is read, we can derive the MacroBlock to SliceGroup mapping (Section 8.2.2 of H264 Spec)
if (_pps.NumSliceGroupsMinus1 > 0)
{
MbToSliceGroupMap = DeriveMB2SliceGroupMap();
}
}
public override void Read(BitReader bitReader)
{
base.Read(bitReader);
PICParamSetID = bitReader.DecodeUnsignedExpGolomb();
SEQParamSetID = bitReader.DecodeUnsignedExpGolomb();
EntropyCodingModeFlag = bitReader.GetNextBit();
PICOrderPresentFlag = bitReader.GetNextBit();
NumSliceGroupsMinus1 = bitReader.DecodeUnsignedExpGolomb();
if (NumSliceGroupsMinus1 > 0)
{
SliceGroupMapType = bitReader.DecodeUnsignedExpGolomb();
switch (SliceGroupMapType)
{
case 0:
RunLengthMinus1 = new uint[NumSliceGroupsMinus1 + 1];
for (int grp = 0; grp <= NumSliceGroupsMinus1; grp++)
{
RunLengthMinus1[grp] = bitReader.DecodeUnsignedExpGolomb();
}
break;
case 1:
break;
case 2:
TopLeft = new uint[NumSliceGroupsMinus1 + 1];
BottomRight = new uint[NumSliceGroupsMinus1 + 1];
for (int grp = 0; grp <= NumSliceGroupsMinus1; grp++) // standards doc, this reads grp < NumSliceGroupsMinus1
{
TopLeft[grp] = bitReader.DecodeUnsignedExpGolomb();
BottomRight[grp] = bitReader.DecodeUnsignedExpGolomb();
}
break;
case 3:
case 4:
case 5:
SliceGroupChangeDirectionFlag = bitReader.GetNextBit();
SliceGroupChangeRateMinus1 = bitReader.DecodeUnsignedExpGolomb();
break;
case 6:
PICSizeInMapUnitsMinus1 = bitReader.DecodeUnsignedExpGolomb();
SliceGroupID = new uint[PICSizeInMapUnitsMinus1 + 1];
ushort bitCount = BitReader.CalcBitsNeededToRepresent(NumSliceGroupsMinus1 + 1);
for (int grp = 0; grp <= PICSizeInMapUnitsMinus1; grp++)
{
SliceGroupID[grp] = bitReader.GetUIntFromNBits(bitCount);
}
break;
default:
throw new Exception("BitReader: bad slice group map type");
}
}
NumRefIDx10ActiveMinus1 = bitReader.DecodeUnsignedExpGolomb();
NumRefIDx11ActiveMinus1 = bitReader.DecodeUnsignedExpGolomb();
WeightedPredFlag = bitReader.GetNextBit();
WeightedBiPredIDC = (ushort)bitReader.GetUIntFromNBits(2);
PICInitQPMinus26 = bitReader.DecodeSignedExpGolomb();
PICInitQSMinus26 = bitReader.DecodeSignedExpGolomb();
ChromaQPIndexOffset = bitReader.DecodeSignedExpGolomb();
DeblockingFilterControlPresentFlag = bitReader.GetNextBit();
ConstrainedIntraPredFlag = bitReader.GetNextBit();
RedundantPICCountPresentFlag = bitReader.GetNextBit();
bitReader.DiscardTrailingBits();
}
