public CabacSliceData(INalUnitReader reader, IState readerState)
{
_reader = reader;
_readerState = readerState;
_sliceState = reader.State.SliceState;
_pictureState = _sliceState.PictureState;
_sequenceState = _pictureState.SequenceState;
_unavailableMacroblockState = _sliceState.IntraCoded
? MacroblockState.UnavailableIntraCoded
: MacroblockState.UnavailableInterCoded;
_macroblockStates = new MacroblockState[PicSizeInMbs];
_motionFieldL0 = IsList0Predicted ? new MotionField(_sliceState) : null;
_motionFieldL1 = IsList1Predicted ? new MotionField(_sliceState) : null;
_subMbTypes = new ISubMacroblockType[4];
_arithmeticDecoder = new ArithmeticDecoder(reader);
for (int i = 0; i < _macroblockStates.Length; i++)
{
_macroblockStates[i] = _unavailableMacroblockState;
}
MbToSliceGroupMap = _mbToSliceGroup.CreateMacroBlockToSliceGroupMap(_sliceState);
}
private void MacroBlockLayer()
{
IMacroblockType macroBlockType = GetMacroblockType();
#if DEBUG
H264Debug.WriteLine("{0}: mb_type={1}", CurrentMbIndex, macroBlockType);
#endif
if (macroBlockType.IsIPcm)
{
_reader.GetPcmSamples();
InitializeCabac();
_currMbState = MacroblockState.Pcm;
}
else
{
bool transform8X8ModeFlagSet = false;
if (macroBlockType.NumMbPart == 4)
{
// Note: Only inter-coded blocks can have mb parts, in particular,
// we are not currently decoding an intra-coded block!
SubMacroBlockPrediction();
if (HasSubMbPartSizeLessThan8X8())
{
transform8X8ModeFlagSet = true; // Transform 8x8 mode is not possible!
}
}
else
{
if (_pictureState.Transform8X8ModeFlag && macroBlockType.IsI_NxN)
{
GetTransformSize8X8Flag();
transform8X8ModeFlagSet = true;
}
MacroBlockPrediction(macroBlockType);
}
if (macroBlockType.IsIntra16X16)
{
_codedBlockPattern = new CodedBlockPattern(macroBlockType.CodedBlockPattern);
}
else
{
GetCodedBlockPattern();
if (_pictureState.Transform8X8ModeFlag && !transform8X8ModeFlagSet &&
_codedBlockPattern.IsLumaResidualPresent &&
(!macroBlockType.IsDirect || _sequenceState.Direct8X8InferenceFlag))
{
GetTransformSize8X8Flag();
}
}
_currMbState.CodedBlockPattern = _codedBlockPattern.Bits;
if (_codedBlockPattern.IsResidualPresent || macroBlockType.IsIntra16X16)
{
GetMbQpDelta(); // mb_qp_delta
Residual(macroBlockType, 0, 15);
}
}
}
public void Parse()
{
InitializeCabac();
_currMbAddr = _sliceState.FirstMacroBlockInSlice * (MbAffFrameFlag ? 2U : 1U);
MbFieldDecodingFlag = _sliceState.FieldPicFlag; // The default for non-MBAFF frames
bool moreDataFlag = true;
bool prevMbSkipped = false;
while (_readerState.Valid && moreDataFlag)
{
_currMbState = new MacroblockState();
_mbQpDeltaNotZero = 0;
// Load macroblock states for block A (left) and B (top)
_mbStateA = GetMacroblockState(_sliceState.GetMbAddrA(_currMbAddr));
_mbStateB = GetMacroblockState(_sliceState.GetMbAddrB(_currMbAddr));
_mbFlags = new MacroblockFlags(_mbStateA.Flags, _mbStateB.Flags);
bool mbSkipFlag = false;
if (!_sliceState.IntraCoded)
{
mbSkipFlag = GetMbSkipFlag(); // mb_skip_flag
}
if (!mbSkipFlag)
{
_mbFlags.SetCodedBlockFlag();
if (MbAffFrameFlag && (IsFirstMacroblockInPair() || prevMbSkipped))
{
MbFieldDecodingFlag = GetMbFieldDecodingFlag(); // is field macro block
}
MacroBlockLayer();
}
if (MbFieldDecodingFlag && (!MbAffFrameFlag || IsLastMacroblockInPair()))
{
_mbFlags.SetFieldDecodingMode();
}
_currMbState.Flags = _mbFlags.Bits;
_macroblockStates[_currMbAddr] = _currMbState;
_prevMbQpDeltaNotZero = _mbQpDeltaNotZero;
if (!_sliceState.IntraCoded)
{
prevMbSkipped = mbSkipFlag;
}
if (!MbAffFrameFlag || IsLastMacroblockInPair())
{
moreDataFlag = !GetEndOfSliceFlag();
}
if (moreDataFlag)
{
NextMbAddress();
}
}
#if DEBUG
H264Debug.WriteLine(" - Terminated ({4}) at {0} of {1} ({2}), nextBits(16)={3}",
_reader.Position, _reader.Length, _currMbAddr, ToBitString(_reader.ShowBits(16), 16),
_sliceState.SliceType.ToString());
#endif
}
