private static void ParseFrameNum(INalUnitReader reader, ISequenceState sequenceState) // TODO:checks uitbreiden volgens 7.4.3(Current Header Semantics).frame_num specs
{
uint frameNum = reader.GetBits((int)sequenceState.Log2MaxFrameNum, Attribute.FrameNumber);
#if DEBUG
H264Debug.WriteLine("+ frame_num={0} ({1} bits)", frameNum, sequenceState.Log2MaxFrameNum);
#endif
if (reader.State.IdrPicFlag && (frameNum != 0))
{
//FIXME: Some H.264 files seem to use frame number != 0 for IDR pictures!?
//readerState.Invalidate();
}
}
public void Parse(INalUnitReader reader, IResultNodeState resultState)
{
var sliceState = reader.State.SliceState;
if (sliceState == null)
{
return; //Apparently no header data is available, so skip the deepslice parsing.
}
#if DEBUG
H264Debug.WriteLine(sliceState.SliceType + " at " + reader.Position + " (" + sliceState.FirstMacroBlockInSlice + ")");
#endif
var sliceData = CreateSliceData(reader, resultState, sliceState);
sliceData.Parse();
H264Debug.DebugEnabled = false;
}
// 7.3.3 Slice header syntax
public void Parse(INalUnitReader reader, IResultNodeState resultState)
{
reader.State.SliceState = null; // Invalid, unless the slice header is valid!
uint firstMacroblockInSlice = reader.GetExpGolombCoded(Attribute.FirstMacroblockInSlice, uint.MaxValue); // first_mb_in_slice
#if DEBUG
H264Debug.WriteLine("+ first_mb_in_slice={0}", firstMacroblockInSlice);
#endif
SliceType pictureSliceType = (SliceType)reader.GetExpGolombCoded(Attribute.SliceType, _sliceTypeResultFormatter);
SliceType sliceType = (SliceType)((int)pictureSliceType % 5);
#if DEBUG
H264Debug.WriteLine("+ slice_type={0}", (int)sliceType);
#endif
byte pictureParamaterSetId = (byte)reader.GetExpGolombCoded(Attribute.PictureParameterSetId, 255);
#if DEBUG
H264Debug.WriteLine("+ pic_parameter_set_id={0}", pictureParamaterSetId);
#endif
var pictureState = reader.State.PictureStates[pictureParamaterSetId];
if (pictureState == null)
{
if (resultState.Valid)
{
if (IsFalseHit(firstMacroblockInSlice, sliceType, pictureParamaterSetId) || (pictureParamaterSetId > 10))
{
resultState.Invalidate();
}
}
return; // cannot validate slice header!!
}
ISliceStateBuilder builder = new SliceStateBuilder(pictureState);
builder.FirstMacroBlockInSlice = firstMacroblockInSlice;
builder.SliceType = sliceType;
if (pictureState.PictureSliceType.HasValue && (sliceType != pictureState.PictureSliceType))
{
// FIXME: This rule only applies to slices within a single picture.
// Since we currently don't detect whether this slice starts a
// new picture, we have to disable this rule for now!
// oldIReaderState.Invalidate();
// return;
}
if (/*!pictureState.PictureSliceType.HasValue && */ sliceType != pictureSliceType)
{
pictureState.PictureSliceType = pictureSliceType;
}
if (IsNonIntraSliceInIntraCodedPicture(reader, sliceType, pictureState))
{
resultState.Invalidate();
return;
}
var sequenceState = pictureState.SequenceState;
if (sequenceState.ChromaFormat == ChromaFormat.SeparateColorPlane)
{
reader.GetBits(2, Attribute.ColorPlane, _colorPlaneResultFormatter); // colour_plane_id
}
ParseFrameNum(reader, sequenceState);
bool fieldPicFlag = false;
if (!sequenceState.FrameMbsOnlyFlag)
{
fieldPicFlag = reader.GetBit(); // field_pic_flag
builder.FieldPicFlag = fieldPicFlag;
if (fieldPicFlag)
{
reader.GetBit(); // bottom_field_flag
}
}
if (reader.State.IdrPicFlag)
{
reader.GetExpGolombCoded(Attribute.IdrPictureId, 65535); // idr_pic_id
}
if (sequenceState.PictureOrderCountType == 0)
{
reader.GetBits((int)sequenceState.Log2MaxPicOrderCntLsb); // pic_order_cnt_lsb
if (pictureState.PictureOrderPresent && !fieldPicFlag)
{
reader.GetSignedExpGolombCoded(); // delta_pic_order_cnt_bottom
}
}
else if ((sequenceState.PictureOrderCountType == 1) && !sequenceState.DeltaPicOrderAlwaysZeroFlag)
{
reader.GetSignedExpGolombCoded(); // delta_pic_order_cnt_0
if (pictureState.PictureOrderPresent && !fieldPicFlag)
{
reader.GetSignedExpGolombCoded(); // delta_pic_order_cnt_1
}
}
if (pictureState.RedundantPictureControlPresent)
{
reader.GetExpGolombCoded(Attribute.RedundantPictureCounter, 127); // redundant_pic_cnt
}
if (sliceType == SliceType.B)
{
reader.GetBit(); // direct_spatial_mv_pred_flag
}
uint activeReferencePictureCount0 = pictureState.DefaultReferencePictureCount0;
uint activeReferencePictureCount1 = pictureState.DefaultReferencePictureCount1;
if (!IsIntraCoded(sliceType) && reader.GetBit()) // num_ref_idx_active_override_flag
{
uint maxRefIdxActiveMinus1 = fieldPicFlag ? 31U : 15U;
activeReferencePictureCount0 = reader.GetExpGolombCoded(maxRefIdxActiveMinus1) + 1; // num_ref_idx_l0_active_minus1
if (sliceType == SliceType.B)
{
activeReferencePictureCount1 = reader.GetExpGolombCoded(maxRefIdxActiveMinus1) + 1; // num_ref_idx_l1_active_minus1
}
}
builder.ActiveReferencePictureCount0 = activeReferencePictureCount0;
builder.ActiveReferencePictureCount1 = activeReferencePictureCount1;
RefPicListModification(reader, resultState, sliceType);
if ((pictureState.WeightedPrediction && (sliceType == SliceType.P || sliceType == SliceType.Sp)) ||
(pictureState.WeightedBidirectionalPrediction == WeightedBidirectionalPredictionType.ExplicitWeightedPrediction && sliceType == SliceType.B))
{
PredWeightTable(reader, sequenceState, sliceType, activeReferencePictureCount0, activeReferencePictureCount1);
}
if (reader.State.NalRefIdc != 0)
{
DecRefPicMarking(reader, resultState);
}
if (pictureState.EntropyCodingMode && !IsIntraCoded(sliceType))
{
builder.CabacInitIdc = reader.GetExpGolombCoded(2U);
}
builder.SliceQpDelta = reader.GetSignedExpGolombCoded();
if ((sliceType == SliceType.Sp) || (sliceType == SliceType.Si))
{
if (sliceType == SliceType.Sp)
{
reader.GetBit(); // sp_for_switch_flag
}
reader.GetSignedExpGolombCoded(); // slice_qs_delta
}
if (pictureState.DeblockingFilterControlPresent)
{
uint disableDeblockingFilterIdc = reader.GetExpGolombCoded(); // disable_deblocking_filter_idc
if (disableDeblockingFilterIdc != 1)
{
reader.GetSignedExpGolombCoded(); // slice_alpha_c0_offset_div2
reader.GetSignedExpGolombCoded(); // slice_beta_offset_div2
}
}
if (pictureState.SliceGroupCount > 1 &&
pictureState.SliceGroupMapType >= SliceGroupMapType.ChangingSliceGroups3 && pictureState.SliceGroupMapType <= SliceGroupMapType.ChangingSliceGroups5)
{
uint value = (sequenceState.PicSizeInMapUnits / pictureState.SliceGroupChangeRate);
int requiredBitsToRepresentValue = DetectorUtils.Log2(value) + 1;
builder.SliceGroupChangeCycle = reader.GetBits(requiredBitsToRepresentValue); // slice_group_change_cycle;
}
// Check 'firstMacroblockInSlice' field
uint picHeightInMbs = sequenceState.FrameHeightInMbs / (fieldPicFlag ? 2U : 1U);
uint picSizeInMbs = sequenceState.PicWidthInMbs * picHeightInMbs;
bool mbAffFrameFlag = sequenceState.MbAdaptiveFrameFieldFlag && !fieldPicFlag;
if ((firstMacroblockInSlice * (mbAffFrameFlag ? 2U : 1U)) >= picSizeInMbs)
{
resultState.Invalidate();
}
if (resultState.Valid)
{
// Since the 'pictureParameterSetId' is probably correct at this point,
// we prevent the check for 'pictureParameterSetId > 10'.
if (IsFalseHit(firstMacroblockInSlice, sliceType, Math.Min((byte)1, pictureParamaterSetId)))
{
resultState.Invalidate();
}
else
{
reader.State.SliceState = builder.Build();
}
}
}
