public void Parse(INalUnitReader reader, IResultNodeState resultState)
{
reader.GetFixedBits(1, 0, Attribute.ForbiddenZeroBit);
reader.State.NalRefIdc = reader.GetBits(2, Attribute.NalRefIdc);
reader.State.NalUnitType = (NalUnitType)reader.GetBits(5, Attribute.NalUnitType);
INalUnitPayloadParser nalUnitPayloadParser;
if (!_nalUnitParsers.TryGetValue(reader.State.NalUnitType, out nalUnitPayloadParser))
{
resultState.Invalidate();
return;
}
//Parse remainder with specific nalunitparser (NOTE: Is not a sub-object)
nalUnitPayloadParser.Parse(reader, resultState);
if (!resultState.Valid)
{
return; // Stop processing of invalid NAL unit.
}
if (!CanParseNalUnitType(reader.State.SliceState, reader.State.NalUnitType))
{
// Forward to the estimated end of the NAL unit
reader.Position = reader.Length;
resultState.Invalidate(); // Invalidates the result
resultState.Recover(); // Revalidates the reader state so parsing can continue!
return;
}
if (reader.State.NalUnitType == NalUnitType.SequenceParameterSet)
{
return; // Note: SPS validate their own data!
}
if (reader.State.NalUnitType == NalUnitType.PictureParameterSet)
{
return; // Note: PPS validate their own data!
}
if (!IsSlice(reader.State.NalUnitType) || !reader.State.SliceState.PictureState.EntropyCodingMode)
{
if (reader.GetBits(1) != 1) // rbsp_stop_one_bit (equal to 1)
{
resultState.Invalidate();
return;
}
}
if (IsSlice(reader.State.NalUnitType) && resultState.Valid)
{
return; // Random (e.g. audio) data is allowed after a valid slice
}
reader.ReadZeroAlignmentBits();
}
private void ParseSliceGroupMap(INalUnitReader reader, IState resultState, IPictureStateBuilder builder, uint sliceGroupCount)
{
var sliceGroupMapType = (SliceGroupMapType)reader.GetExpGolombCoded(Attribute.SliceGroupMapType, _sliceGroupMapTypeFormatter); // slice_group_map_type
builder.SliceGroupMapType = sliceGroupMapType;
switch (sliceGroupMapType)
{
case SliceGroupMapType.InterleavedSliceGroups:
uint[] runLengthMinus1 = new uint[sliceGroupCount];
for (int iGroup = 0; iGroup < sliceGroupCount; iGroup++)
{
runLengthMinus1[iGroup] = reader.GetExpGolombCoded(); // run_length_minus1[iGroup]
}
builder.RunLengthMinus1 = runLengthMinus1;
break;
case SliceGroupMapType.DispersedSliceGroups:
break;
case SliceGroupMapType.ForegroundAndLeftoverSliceGroups:
uint[] topLeft = new uint[sliceGroupCount - 1];
uint[] bottomRight = new uint[sliceGroupCount - 1];
for (int iGroup = 0; iGroup < (sliceGroupCount - 1); iGroup++)
{
topLeft[iGroup] = reader.GetExpGolombCoded();
bottomRight[iGroup] = reader.GetExpGolombCoded();
}
builder.TopLeft = topLeft;
builder.BottomRight = bottomRight;
break;
case SliceGroupMapType.ChangingSliceGroups3:
case SliceGroupMapType.ChangingSliceGroups4:
case SliceGroupMapType.ChangingSliceGroups5:
builder.SliceGroupChangeDirectionFlag = reader.GetBit();
builder.SliceGroupChangeRateMinus1 = reader.GetExpGolombCoded();
break;
case SliceGroupMapType.ExplicitSliceGroups:
uint pictureSizeInMapUnits = 1 + reader.GetExpGolombCoded(); // pic_size_in_map_units_minus1
int syntaxElementSize = DetectorUtils.Log2(sliceGroupCount - 1) + 1;
uint[] sliceGroupId = new uint[pictureSizeInMapUnits];
for (int i = 0; i < pictureSizeInMapUnits; i++)
{
sliceGroupId[i] = reader.GetBits(syntaxElementSize);
}
builder.SliceGroupId = sliceGroupId;
break;
default:
resultState.Invalidate();
break;
}
}
private static void GetHrdParameters(INalUnitReader reader, IState resultState)
{
uint cpbCntMinus1 = reader.GetExpGolombCoded(); // cpb_cnt_minus1
reader.GetBits(4); // bit_rate_scale
reader.GetBits(4); // cpb_size_scale
// for (SchedSelIdx = 0; SchedSelIdx <= cpb_cnt_minus1; SchedSelIdx++)
for (int schedSelIdx = 0; schedSelIdx <= cpbCntMinus1; schedSelIdx++)
{
if (!reader.HasMoreRbspData())
{
resultState.Invalidate();
return;
}
reader.GetExpGolombCoded(); // bit_rate_value_minus1[SchedSelIdx]
reader.GetExpGolombCoded(); // cpb_size_value_minus1[SchedSelIdx]
reader.GetBit(); // cbr_flag[SchedSelIdx]
}
reader.GetBits(5); // initial_cpb_removal_delay_length_minus1
reader.GetBits(5); // cpb_removal_delay_length_minus1
reader.GetBits(5); // dpb_output_delay_length_minus1
reader.GetBits(5); // time_offset_length
}
// 7.3.2.2 PictureState parameter set RBSP syntax
public void Parse(INalUnitReader reader, IResultNodeState resultState)
{
resultState.Name = Name;
uint pictureParameterSetId = reader.GetExpGolombCoded(Attribute.PictureParameterSetId, 255 /*7.4.2.2*/);
uint sequenceParameterSetId = reader.GetExpGolombCoded(Attribute.SequenceParameterSetId, 31 /*7.4.2.2*/);
var sequenceState = reader.State.SequenceStates[sequenceParameterSetId];
if (sequenceState == null)
{
resultState.Invalidate();
return;
}
IPictureStateBuilder builder = new PictureStateBuilder(pictureParameterSetId, sequenceState);
builder.EntropyCodingMode = reader.GetBit(Attribute.EntropyCodingMode);
builder.BottomFieldPicOrderInFramePresentFlag = reader.GetBit(Attribute.PictureOrderPresent);
uint numSliceGroupsMinus1 = reader.GetExpGolombCoded(Attribute.NumSliceGroupsMinus1, 7 /*A.2*/);
builder.NumSliceGroupsMinus1 = numSliceGroupsMinus1;
if (numSliceGroupsMinus1 > 0)
{
if (sequenceState.Profile == Profile.Main)
{
resultState.Invalidate();
return;
}
ParseSliceGroupMap(reader, resultState, builder, (numSliceGroupsMinus1 + 1));
// FIXME: this code contains too many bugs, so it is disabled for now!
resultState.Invalidate();
// (end of FIXME)
if (!resultState.Valid)
{
return;
}
}
builder.NumRefIdxL0DefaultActiveMinus1 = reader.GetExpGolombCoded(Attribute.NumRefIdxl0DefaultActiveMinus1, 31 /*7.4.2.2*/);
builder.NumRefIdxL1DefaultActiveMinus1 = reader.GetExpGolombCoded(Attribute.NumRefIdxl1DefaultActiveMinus1, 31 /*7.4.2.2*/);
builder.WeightedPredFlag = reader.GetBit(Attribute.WeightedPrediction);
builder.WeightedBipredIdc = reader.GetBits(2, Attribute.WeightedBidirectionalPrediction, _weightBidirectionalPredictionFormatter);
// SliceQPY = 26 + PicInitQpMinus26 + slice_qp_delta
int qpBdOffset = (6 * ((int)sequenceState.BitDepthLuma - 8));
builder.PicInitQpMinus26 = reader.GetSignedExpGolombCoded(Attribute.PictureInitialQPyMinus26, -(26 + qpBdOffset), 25);
reader.GetSignedExpGolombCoded(Attribute.PictureInitialQSyMinus26, -26, 25); // pic_init_qs_minus26; relative to 26
reader.GetSignedExpGolombCoded(Attribute.ChromaQpIndexOffset, -12, 12); // chroma_qp_index_offset
builder.DeblockingFilterControlPresentFlag = reader.GetBit(Attribute.DeblockingFilterControlPresent);
reader.GetBit(Attribute.ConstrainedIntraPrediction); // constrained_intra_pred_flag
builder.RedundantPicCntPresentFlag = reader.GetBit(Attribute.RedundantPictureControlPresent);
// Note: Total size upto this point is between 11 and 59 bits (+ 'slice group map')
if (reader.HasMoreRbspData()) // more_rbsp_data()
{
builder.Transform8X8ModeFlag = reader.GetBit(); // transform_8x8_mode_flag
bool picScalingMatrixPresentFlag = reader.GetBit();
//if (picScalingMatrixPresentFlag) // pic_scaling_matrix_present_flag
//{
// for (int i = 0; i < 6 + 2 * pictureState.transform_8x8_mode_flag; i++)
// {
// bool picScalingListPresentFlag = reader.GetBit();
// if (picScalingListPresentFlag) // pic_scaling_list_present_flag[i]
// {
// if (i < 6)
// {
// throw new NotImplementedException("scaling_list(ScalingList4x4[i], 16, UseDefaultScalingMatrix4x4Flag[i]);"); // TODO
// }
// else
// {
// throw new NotImplementedException("scaling_list(ScalingList8x8[i – 6], 64, UseDefaultScalingMatrix8x8Flag[i – 6]);"); // TODO
// }
// }
// }
//}
reader.GetSignedExpGolombCoded(); // second_chroma_qp_index_offset
}
// rbsp_trailing_bits()
if (reader.ShowBits(1) == 1)
{
reader.GetBit(); // rbsp_stop_one_bit (equal to 1)
// trailing zero bits
}
if (resultState.Valid)
{
reader.State.PictureStates[pictureParameterSetId] = builder.Build();
}
}
private void ResidualBlockCavlc(int startIdx, int endIdx, int maxNumCoeff, CoeffToken coeffToken)
{
int suffixLength = ((coeffToken.TotalCoeff > 10) && (coeffToken.TrailingOnes < 3)) ? 1 : 0;
#if DEBUG
H264Debug.Write(" - levels=");
if (coeffToken.TrailingOnes > 0)
{
uint signs = _reader.GetBits(coeffToken.TrailingOnes); // (n) x trailing_ones_sign_flag
for (int i = 0; i < coeffToken.TrailingOnes; i++)
{
H264Debug.Write((((signs & (1 << (coeffToken.TrailingOnes - 1 - i))) == 0) ? "1," : "-1,"));
}
}
#else
_reader.GetBits(coeffToken.TrailingOnes); // (n) x trailing_ones_sign_flag
#endif
for (int i = coeffToken.TrailingOnes; i < coeffToken.TotalCoeff; i++)
{
int levelCode = GetCoefficientLevelCode(suffixLength);
// The first non-zero coefficient after 'trailing ones' must be larger than 1,
// unless the maximum count of trailing ones, i.e. 3, was reached.
// This will further reduce the amount of bits required to represent a
// coefficient level.
if ((i == coeffToken.TrailingOnes) && (i /*trailing ones*/ < 3))
{
levelCode += 2; // 2 instead of 1, because the lowest bit is the sign bit!
}
#if DEBUG
H264Debug.Write("{0},", ((levelCode % 2) == 0) ? ((levelCode + 2) >> 1) : ((-levelCode - 1) >> 1));
#endif
// Automatically adjust the suffix length if high coefficients levels are
// encountered, to reduce the number of bits required to represent subsequent
// high coefficient levels.
if (suffixLength == 0)
{
suffixLength = 1;
}
if (suffixLength < 6)
{
int absLevelMinusOne = (levelCode >> 1);
if (absLevelMinusOne >= (3 << (suffixLength - 1)))
{
suffixLength++;
}
}
}
#if DEBUG
H264Debug.WriteLine();
#endif
if (coeffToken.TotalCoeff < (endIdx - startIdx + 1))
{
int zerosLeft = GetTotalZeros(coeffToken.TotalCoeff, maxNumCoeff); // total_zeros
#if DEBUG
H264Debug.WriteLine(" - total_zeros={0}", zerosLeft);
H264Debug.WriteLine("ShowBits(32) = {0:x8} at {1:x8}", _reader.ShowBits(32), _reader.Position);
H264Debug.Write(" - run_before=");
#endif
for (int i = 0; i < (coeffToken.TotalCoeff - 1) && (zerosLeft > 0); i++)
{
#if DEBUG
int runBefore = _reader.GetVlc(RunBeforeTable[Math.Min(zerosLeft, 7)]);
zerosLeft -= runBefore; // run_before
H264Debug.Write("{0},", runBefore);
#else
zerosLeft -= _reader.GetVlc(RunBeforeTable[Math.Min(zerosLeft, 7)]); // run_before
#endif
}
#if DEBUG
H264Debug.WriteLine();
#endif
}
}
// 7.3.2.1.1 SequenceState parameter set data syntax
public void Parse(INalUnitReader reader, IResultNodeState resultState)
{
// Constraints from 7.4.2.11
resultState.Name = Name;
Profile profileIdc = reader.GetBits(8, Attribute.ProfileIdc, _profileValidator);
reader.GetBits(6); // constraint_set{0-5}_flag
if (reader.GetBits(2) != 0) // reserved_zero_2bits
{
resultState.Invalidate();
return;
}
reader.GetByte(false, Attribute.LevelIdc, 59); // level_idc, Table A-1 - Level limits
uint sequenceParameterSetId = reader.GetExpGolombCoded(Attribute.SequenceParameterSetId, 31);
ISequenceStateBuilder builder = new SequenceStateBuilder(sequenceParameterSetId);
builder.ByteStreamFormat = reader.State.ByteStreamFormat;
builder.ProfileIdc = profileIdc;
if (IsHighProfile(profileIdc))
{
uint chromaFormatIdc = reader.GetExpGolombCoded(Attribute.ChromaFormatIdc, 3); // Table 6-1
builder.ChromaFormatIdc = chromaFormatIdc;
if (chromaFormatIdc == 3)
{
builder.SeparateColourPlaneFlag = reader.GetBit(Attribute.SeparateColorPlaneFlag);
}
builder.BitDepthLumaMinus8 = reader.GetExpGolombCoded(Attribute.BitDepthLumaArraySampleMinus8, 6);
builder.BitDepthChromaMinus8 = reader.GetExpGolombCoded(Attribute.BitDepthChromaArraySampleMinus8, 6);
reader.GetBit(); // qpprime_y_zero_transform_bypass_flag
if (reader.GetBit()) // seq_scaling_matrix_present_flag
{
for (int i = 0; i < ((chromaFormatIdc != 3) ? 8 : 12); i++)
{
if (reader.GetBit()) // seq_scaling_list_present_flag[i]
{
// FIXME: scaling_list() is not implemented!!
resultState.Invalidate();
return;
}
}
}
}
builder.Log2MaxFrameNumMinus4 = reader.GetExpGolombCoded(Attribute.Log2MaxFrameNumMinus4, 28);
DecodePictureOrderCount(reader, builder);
uint maxDpbFramesUpperLimit = (profileIdc == Profile.MultiviewHigh) ? 160U : 16U; //could use the exact maxDpbFrames, but this is easier
builder.MaxNumRefFrames = reader.GetExpGolombCoded(Attribute.MaxNumberReferenceFrames, maxDpbFramesUpperLimit);
reader.GetBit(); // gaps_in_frame_num_value_allowed_flag
builder.PicWidthInMbsMinus1 = reader.GetExpGolombCoded(Attribute.PictureWidthInMacroBlocksMinus1, 543);
builder.PicHeightInMapUnitsMinus1 = reader.GetExpGolombCoded(Attribute.PictureHeightInMapUnitsMinus1, 543);
var frameMbsOnlyFlag = reader.GetBit(Attribute.FrameMbsOnlyFlag);
builder.FrameMbsOnlyFlag = frameMbsOnlyFlag;
if (!frameMbsOnlyFlag)
{
builder.MbAdaptiveFrameFieldFlag = reader.GetBit();
}
bool direct8X8InferenceFlag = reader.GetBit();
builder.Direct8X8InferenceFlag = direct8X8InferenceFlag;
if (!frameMbsOnlyFlag && !direct8X8InferenceFlag)
{
resultState.Invalidate();
return;
}
if (reader.GetBit()) // frame_cropping_flag
{
// TODO: Cropping should not exceed the size of a frame!
reader.GetExpGolombCoded(Attribute.FrameCropLeftOffset, 8703);
reader.GetExpGolombCoded(Attribute.FrameCropRightOffset, 8703);
reader.GetExpGolombCoded(Attribute.FrameCropTopOffset, 8703);
reader.GetExpGolombCoded(Attribute.FrameCropBottomOffset, 8703);
}
if (reader.GetBit()) // vui_parameters_present_flag
{
GetVuiParameters(reader, resultState);
}
if (reader.ShowBits(1) == 1)
{
reader.GetBit(); // rbsp_stop_one_bit (equal to 1)
// trailing zero bits
}
if (resultState.Valid)
{
reader.State.SequenceStates[sequenceParameterSetId] = builder.Build();
}
}
private static void GetVuiParameters(INalUnitReader reader, IResultNodeState resultState)
{
const byte extendedSar = 255; // Extended_SAR
bool aspectRatioInfoPresentFlag = reader.GetBit();
if (aspectRatioInfoPresentFlag) // aspect_ratio_info_present_flag
{
byte aspectRatioIdc = reader.GetByte(false);
if (aspectRatioIdc == extendedSar) // aspect_ratio_idc
{
reader.GetBits(16); // sar_width
reader.GetBits(16); // sar_height
}
}
bool overscanInfoPresentFlag = reader.GetBit();
if (overscanInfoPresentFlag) // overscan_info_present_flag
{
reader.GetBit(); // overscan_appropriate_flag
}
bool videoSignalTypePresentFlag = reader.GetBit();
if (videoSignalTypePresentFlag) // video_signal_type_present_flag
{
reader.GetBits(3); // video_format
reader.GetBit(); // video_full_range_flag
bool colourDescriptionPresentFlag = reader.GetBit();
if (colourDescriptionPresentFlag) // colour_description_present_flag
{
reader.GetByte(false); // colour_primaries
reader.GetByte(false); // transfer_characteristics
reader.GetByte(false); // matrix_coefficients
}
}
bool chromaLocInfoPresentFlag = reader.GetBit();
if (chromaLocInfoPresentFlag) // chroma_loc_info_present_flag
{
reader.GetExpGolombCoded(); // chroma_sample_loc_type_top_field
reader.GetExpGolombCoded(); // chroma_sample_loc_type_bottom_field
}
bool timingInfoPresentFlag = reader.GetBit();
if (timingInfoPresentFlag) // timing_info_present_flag
{
reader.GetBits(32); // num_units_in_tick
reader.GetBits(32); // time_scale
reader.GetBit(); // fixed_frame_rate_flag
}
bool nalHrdParametersPresentFlag = reader.GetBit();
if (nalHrdParametersPresentFlag) //nal_hrd_parameters_present_flag
{
GetHrdParameters(reader, resultState); // hrd_parameters()
}
bool vclHrdParametersPresentFlag = reader.GetBit();
if (vclHrdParametersPresentFlag) // vcl_hrd_parameters_present_flag
{
GetHrdParameters(reader, resultState); // hrd_parameters()
}
if (nalHrdParametersPresentFlag || vclHrdParametersPresentFlag)
{
reader.GetBit(); // low_delay_hrd_flag
}
reader.GetBit(); // pic_struct_present_flag
bool bitstreamRestrictionFlag = reader.GetBit();
if (bitstreamRestrictionFlag) // bitstream_restriction_flag
{
reader.GetBit(); // motion_vectors_over_pic_boundaries_flag
reader.GetExpGolombCoded(); // max_bytes_per_pic_denom
reader.GetExpGolombCoded(); // max_bits_per_mb_denom
reader.GetExpGolombCoded(); // log2_max_mv_length_horizontal
reader.GetExpGolombCoded(); // log2_max_mv_length_vertical
reader.GetExpGolombCoded(); // num_reorder_frames
reader.GetExpGolombCoded(); // max_dec_frame_buffering
}
}