private bool ParseItemSequenceTag(IByteSource source)
{
if (this.parseStage == ParseStage.Tag)
{
source.Mark();
if (!source.Require(8))
{
this.result = DicomReaderResult.Suspended;
return(false);
}
var group = source.GetUInt16();
var element = source.GetUInt16();
this._tag = new DicomTag(@group, element);
if (this._tag != DicomTag.Item && this._tag != DicomTag.SequenceDelimitationItem)
{
// assume invalid sequence
source.Rewind();
if (!this._implicit)
{
source.PopMilestone();
}
this.observer.OnEndSequence();
if (this.badPrivateSequence)
{
this.isExplicitVR = !this.isExplicitVR;
this.badPrivateSequence = false;
}
return(false);
}
this.length = source.GetUInt32();
if (this._tag == DicomTag.SequenceDelimitationItem)
{
// #64, in case explicit length has been specified despite occurrence of Sequence Delimitation Item
if (source.HasReachedMilestone() && source.MilestonesCount > this.sequenceDepth)
{
this.ResetState();
return(true);
}
// end of sequence
this.observer.OnEndSequence();
if (this.badPrivateSequence)
{
this.isExplicitVR = !this.isExplicitVR;
this.badPrivateSequence = false;
}
this.ResetState();
return(false);
}
this.parseStage = ParseStage.Value;
}
return(true);
}
private async Task ParseDatasetAsync(IByteSource source)
{
if (this.isDeflated)
{
source = this.Decompress(source);
}
this.result = DicomReaderResult.Processing;
while (!source.IsEOF && !source.HasReachedMilestone() && this.result == DicomReaderResult.Processing)
{
if (!this.ParseTag(source))
{
return;
}
if (!this.ParseVR(source))
{
return;
}
if (!this.ParseLength(source))
{
return;
}
if (!await this.ParseValueAsync(source).ConfigureAwait(false))
{
return;
}
}
if (source.HasReachedMilestone())
{
// end of explicit length sequence item
source.PopMilestone();
return;
}
if (this.result != DicomReaderResult.Processing)
{
return;
}
// end of processing
this.result = DicomReaderResult.Success;
}
private void ParseDataset(IByteSource source)
{
if (_isDeflated)
{
source = Decompress(source);
}
_result = DicomReaderResult.Processing;
while (!source.IsEOF && !source.HasReachedMilestone() && _result == DicomReaderResult.Processing)
{
if (!ParseTag(source))
{
return;
}
if (!ParseVR(source))
{
return;
}
if (!ParseLength(source))
{
return;
}
if (!ParseValue(source))
{
return;
}
}
if (source.HasReachedMilestone())
{
// end of explicit length sequence item
source.PopMilestone();
return;
}
if (_result != DicomReaderResult.Processing)
{
return;
}
// end of processing
_result = DicomReaderResult.Success;
}
private void ParseItemSequencePostProcess(IByteSource source)
{
// end of explicit length sequence
if (source.HasReachedMilestone())
{
source.PopMilestone();
}
this.observer.OnEndSequence();
if (this.badPrivateSequence)
{
this.isExplicitVR = !this.isExplicitVR;
this.badPrivateSequence = false;
}
}
private void ParseItemSequencePostProcess(IByteSource source)
{
// end of explicit length sequence
if (source.HasReachedMilestone())
{
source.PopMilestone();
}
_observer.OnEndSequence();
// #565 Only reset the badPrivate sequence if we're in the correct depth
// This prevents prematurely resetting in case of sub-sequences contained in the bad private sequence
if (_badPrivateSequence && _sequenceDepth == _badPrivateSequenceDepth)
{
_isExplicitVR = !_isExplicitVR;
_badPrivateSequence = false;
}
}
private async Task ParseItemSequenceAsync(IByteSource source)
{
_result = DicomReaderResult.Processing;
while (!source.IsEOF && !source.HasReachedMilestone())
{
if (!ParseItemSequenceTag(source))
{
return;
}
if (!await ParseItemSequenceValueAsync(source).ConfigureAwait(false))
{
return;
}
}
ParseItemSequencePostProcess(source);
}
private void ParseItemSequence(IByteSource source)
{
_result = DicomReaderResult.Processing;
while (!source.IsEOF && !source.HasReachedMilestone())
{
if (!ParseItemSequenceTag(source))
{
return;
}
if (!ParseItemSequenceValue(source))
{
return;
}
}
ParseItemSequencePostProcess(source);
}
private bool ParseItemSequenceTag(IByteSource source)
{
if (_parseStage == ParseStage.Tag)
{
source.Mark();
if (!source.Require(8))
{
_result = DicomReaderResult.Suspended;
return(false);
}
var group = source.GetUInt16();
var element = source.GetUInt16();
_tag = new DicomTag(@group, element);
if (_tag != DicomTag.Item && _tag != DicomTag.SequenceDelimitationItem)
{
// assume invalid sequence
source.Rewind();
if (!_implicit)
{
source.PopMilestone();
}
_observer.OnEndSequence();
// #565 Only reset the badPrivate sequence if we're in the correct depth
// This prevents prematurely resetting in case of sub-sequences contained in the bad private sequence
if (_badPrivateSequence && _sequenceDepth == _badPrivateSequenceDepth)
{
_isExplicitVR = !_isExplicitVR;
_badPrivateSequence = false;
}
return(false);
}
_length = source.GetUInt32();
if (_tag == DicomTag.SequenceDelimitationItem)
{
// #64, in case explicit length has been specified despite occurrence of Sequence Delimitation Item
if (source.HasReachedMilestone() && source.MilestonesCount > _sequenceDepth)
{
ResetState();
return(true);
}
// end of sequence
_observer.OnEndSequence();
// #565 Only reset the badPrivate sequence if we're in the correct depth
// This prevents prematurely resetting in case of sub-sequences contained in the bad private sequence
if (_badPrivateSequence && _sequenceDepth == _badPrivateSequenceDepth)
{
_isExplicitVR = !_isExplicitVR;
_badPrivateSequence = false;
}
ResetState();
return(false);
}
_parseStage = ParseStage.Value;
}
return(true);
}
private void ParseItemSequencePostProcess(IByteSource source)
{
// end of explicit length sequence
if (source.HasReachedMilestone())
{
source.PopMilestone();
}
this.observer.OnEndSequence();
if (this.badPrivateSequence)
{
this.isExplicitVR = !this.isExplicitVR;
this.badPrivateSequence = false;
}
}
private void ParseItemSequence(IByteSource source, object state)
{
try {
_result = DicomReaderResult.Processing;
while (!source.IsEOF && !source.HasReachedMilestone())
{
if (_state == ParseState.Tag)
{
source.Mark();
if (!source.Require(8, ParseItemSequence, state))
{
_result = DicomReaderResult.Suspended;
return;
}
ushort group = source.GetUInt16();
ushort element = source.GetUInt16();
_tag = new DicomTag(group, element);
if (_tag != DicomTag.Item && _tag != DicomTag.SequenceDelimitationItem)
{
// assume invalid sequence
source.Rewind();
if (!_implicit)
{
source.PopMilestone();
}
_observer.OnEndSequence();
if (_badPrivateSequence)
{
_explicit = !_explicit;
_badPrivateSequence = false;
}
return;
}
_length = source.GetUInt32();
if (_tag == DicomTag.SequenceDelimitationItem)
{
// end of sequence
_observer.OnEndSequence();
if (_badPrivateSequence)
{
_explicit = !_explicit;
_badPrivateSequence = false;
}
ResetState();
return;
}
_state = ParseState.Value;
}
if (_state == ParseState.Value)
{
if (_length != UndefinedLength)
{
if (!source.Require(_length, ParseItemSequence, state))
{
_result = DicomReaderResult.Suspended;
return;
}
source.PushMilestone(_length);
}
_observer.OnBeginSequenceItem(source, _length);
ResetState();
ParseDataset(source, state);
ResetState();
_observer.OnEndSequenceItem();
continue;
}
}
// end of explicit length sequence
if (source.HasReachedMilestone())
{
source.PopMilestone();
}
_observer.OnEndSequence();
if (_badPrivateSequence)
{
_explicit = !_explicit;
_badPrivateSequence = false;
}
} catch (Exception e) {
_exception = e;
_result = DicomReaderResult.Error;
} finally {
if (_result != DicomReaderResult.Processing && _result != DicomReaderResult.Suspended)
{
_async.Set();
}
}
}
private void ParseItemSequence(IByteSource source)
{
this.result = DicomReaderResult.Processing;
while (!source.IsEOF && !source.HasReachedMilestone())
{
if (!this.ParseItemSequenceTag(source)) return;
if (!this.ParseItemSequenceValue(source)) return;
}
this.ParseItemSequencePostProcess(source);
}
private async Task ParseDatasetAsync(IByteSource source)
{
this.result = DicomReaderResult.Processing;
while (!source.IsEOF && !source.HasReachedMilestone() && this.result == DicomReaderResult.Processing)
{
if (!this.ParseTag(source)) return;
if (!this.ParseVR(source)) return;
if (!this.ParseLength(source)) return;
if (!await this.ParseValueAsync(source).ConfigureAwait(false)) return;
}
if (source.HasReachedMilestone())
{
// end of explicit length sequence item
source.PopMilestone();
return;
}
if (this.result != DicomReaderResult.Processing) return;
// end of processing
this.result = DicomReaderResult.Success;
}
private void ParseDataset(IByteSource source)
{
this.result = DicomReaderResult.Processing;
while (!source.IsEOF && !source.HasReachedMilestone() && this.result == DicomReaderResult.Processing)
{
if (!this.ParseTag(source)) return;
if (!this.ParseVR(source)) return;
if (!this.ParseLength(source)) return;
if (!this.ParseValue(source)) return;
}
if (source.HasReachedMilestone())
{
// end of explicit length sequence item
source.PopMilestone();
return;
}
if (this.result != DicomReaderResult.Processing) return;
// end of processing
this.result = DicomReaderResult.Success;
}
private void ParseDataset(IByteSource source)
{
if (this.isDeflated)
{
#if NET35
throw new NotSupportedException("Deflated datasets not supported in Unity.");
#else
source = this.Decompress(source);
#endif
}
this.result = DicomReaderResult.Processing;
while (!source.IsEOF && !source.HasReachedMilestone() && this.result == DicomReaderResult.Processing)
{
if (!this.ParseTag(source)) return;
if (!this.ParseVR(source)) return;
if (!this.ParseLength(source)) return;
if (!this.ParseValue(source)) return;
}
if (source.HasReachedMilestone())
{
// end of explicit length sequence item
source.PopMilestone();
return;
}
if (this.result != DicomReaderResult.Processing) return;
// end of processing
this.result = DicomReaderResult.Success;
}
private void ParseDataset(IByteSource source, object state)
{
try {
_result = DicomReaderResult.Processing;
while (!source.IsEOF && !source.HasReachedMilestone())
{
if (_state == ParseState.Tag)
{
source.Mark();
if (!source.Require(4, ParseDataset, state))
{
_result = DicomReaderResult.Suspended;
return;
}
ushort group = source.GetUInt16();
ushort element = source.GetUInt16();
DicomPrivateCreator creator = null;
if (group.IsOdd() && element > 0x00ff)
{
string pvt = null;
uint card = (uint)(group << 16) + (uint)(element >> 8);
if (_private.TryGetValue(card, out pvt))
{
creator = Dictionary.GetPrivateCreator(pvt);
}
}
_tag = new DicomTag(group, element, creator);
if (_stop != null && _tag.CompareTo(_stop) >= 0)
{
_result = DicomReaderResult.Stopped;
return;
}
_state = ParseState.VR;
}
while (_state == ParseState.VR)
{
if (_tag == DicomTag.Item || _tag == DicomTag.ItemDelimitationItem || _tag == DicomTag.SequenceDelimitationItem)
{
_vr = DicomVR.NONE;
_state = ParseState.Length;
break;
}
if (IsExplicitVR)
{
if (!source.Require(2, ParseDataset, state))
{
_result = DicomReaderResult.Suspended;
return;
}
byte[] bytes = source.GetBytes(2);
string vr = Encoding.ASCII.GetString(bytes);
_vr = DicomVR.Parse(vr);
}
else
{
DicomDictionaryEntry entry = Dictionary[_tag];
if (entry != null)
{
if (entry.ValueRepresentations.Contains(DicomVR.OB) && entry.ValueRepresentations.Contains(DicomVR.OW))
{
_vr = DicomVR.OW; // ???
}
else
{
_vr = entry.ValueRepresentations.FirstOrDefault();
}
}
}
if (_vr == null)
{
_vr = DicomVR.UN;
}
_state = ParseState.Length;
if (_vr == DicomVR.UN)
{
if (_tag.Element == 0x0000)
{
// Group Length to UL
_vr = DicomVR.UL;
break;
}
if (_tag.Group.IsOdd())
{
if (_tag.Element <= 0x00ff)
{
// Private Creator to LO
_vr = DicomVR.LO;
break;
}
else if (IsExplicitVR)
{
DicomDictionaryEntry entry = Dictionary[_tag];
if (entry != null)
{
_vr = entry.ValueRepresentations.FirstOrDefault();
}
if (_vr == null)
{
_vr = DicomVR.UN;
}
break;
}
}
}
}
while (_state == ParseState.Length)
{
if (_tag == DicomTag.Item || _tag == DicomTag.ItemDelimitationItem || _tag == DicomTag.SequenceDelimitationItem)
{
if (!source.Require(4, ParseDataset, state))
{
_result = DicomReaderResult.Suspended;
return;
}
_length = source.GetUInt32();
_state = ParseState.Value;
break;
}
if (IsExplicitVR)
{
if (_vr.Is16bitLength)
{
if (!source.Require(2, ParseDataset, state))
{
_result = DicomReaderResult.Suspended;
return;
}
_length = source.GetUInt16();
}
else
{
if (!source.Require(6, ParseDataset, state))
{
_result = DicomReaderResult.Suspended;
return;
}
source.Skip(2);
_length = source.GetUInt32();
}
}
else
{
if (!source.Require(4, ParseDataset, state))
{
_result = DicomReaderResult.Suspended;
return;
}
_length = source.GetUInt32();
}
_state = ParseState.Value;
}
if (_state == ParseState.Value)
{
if (_tag == DicomTag.ItemDelimitationItem)
{
// end of sequence item
ParseItemSequence(source, state);
return;
}
if (_vr == DicomVR.SQ)
{
// start of sequence
_observer.OnBeginSequence(source, _tag, _length);
_state = ParseState.Tag;
if (_length != UndefinedLength)
{
source.PushMilestone(_length);
}
PushState(state);
ParseItemSequence(source, null);
continue;
}
if (_length == UndefinedLength)
{
_observer.OnBeginFragmentSequence(source, _tag, _vr);
_state = ParseState.Tag;
PushState(state);
ParseFragmentSequence(source, null);
continue;
}
if (!source.Require(_length, ParseDataset, state))
{
_result = DicomReaderResult.Suspended;
return;
}
IByteBuffer buffer = source.GetBuffer(_length);
if (!_vr.IsString)
{
buffer = EndianByteBuffer.Create(buffer, source.Endian, _vr.UnitSize);
}
_observer.OnElement(source, _tag, _vr, buffer);
ResetState();
}
}
if (source.HasReachedMilestone())
{
// end of explicit length sequence item
_observer.OnEndSequenceItem();
source.PopMilestone();
ParseItemSequence(source, state);
return;
}
// end of processing
_result = DicomReaderResult.Success;
} catch (Exception e) {
_exception = e;
_result = DicomReaderResult.Error;
} finally {
if (_result != DicomReaderResult.Processing && _result != DicomReaderResult.Suspended)
{
_async.Set();
}
}
}
private void ParseItemSequence(IByteSource source, object state) {
try {
_result = DicomReaderResult.Processing;
while (!source.IsEOF && !source.HasReachedMilestone()) {
if (_state == ParseState.Tag) {
source.Mark();
if (!source.Require(8, ParseItemSequence, state)) {
_result = DicomReaderResult.Suspended;
return;
}
ushort group = source.GetUInt16();
ushort element = source.GetUInt16();
_tag = new DicomTag(group, element);
if (_tag != DicomTag.Item && _tag != DicomTag.SequenceDelimitationItem) {
// assume invalid sequence
source.Rewind();
if (!_implicit)
source.PopMilestone();
_observer.OnEndSequence();
if (_badPrivateSequence) {
_explicit = !_explicit;
_badPrivateSequence = false;
}
return;
}
_length = source.GetUInt32();
if (_tag == DicomTag.SequenceDelimitationItem) {
// end of sequence
_observer.OnEndSequence();
if (_badPrivateSequence) {
_explicit = !_explicit;
_badPrivateSequence = false;
}
ResetState();
return;
}
_state = ParseState.Value;
}
if (_state == ParseState.Value) {
if (_length != UndefinedLength) {
if (!source.Require(_length, ParseItemSequence, state)) {
_result = DicomReaderResult.Suspended;
return;
}
source.PushMilestone(_length);
}
_observer.OnBeginSequenceItem(source, _length);
ResetState();
ParseDataset(source, state);
ResetState();
_observer.OnEndSequenceItem();
continue;
}
}
// end of explicit length sequence
if (source.HasReachedMilestone())
source.PopMilestone();
_observer.OnEndSequence();
if (_badPrivateSequence) {
_explicit = !_explicit;
_badPrivateSequence = false;
}
} catch (Exception e) {
_exception = e;
_result = DicomReaderResult.Error;
} finally {
if (_result != DicomReaderResult.Processing && _result != DicomReaderResult.Suspended) {
_async.Set();
}
}
}
private void ParseDataset(IByteSource source, object state) {
try {
_result = DicomReaderResult.Processing;
while (!source.IsEOF && !source.HasReachedMilestone() && _result == DicomReaderResult.Processing) {
if (_state == ParseState.Tag) {
source.Mark();
if (!source.Require(4, ParseDataset, state)) {
_result = DicomReaderResult.Suspended;
return;
}
ushort group = source.GetUInt16();
ushort element = source.GetUInt16();
DicomPrivateCreator creator = null;
if (group.IsOdd() && element > 0x00ff) {
string pvt = null;
uint card = (uint)(group << 16) + (uint)(element >> 8);
if (_private.TryGetValue(card, out pvt))
creator = Dictionary.GetPrivateCreator(pvt);
}
_tag = new DicomTag(group, element, creator);
if (_stop != null && _tag.CompareTo(_stop) >= 0) {
_result = DicomReaderResult.Stopped;
return;
}
_state = ParseState.VR;
}
while (_state == ParseState.VR) {
if (_tag == DicomTag.Item || _tag == DicomTag.ItemDelimitationItem || _tag == DicomTag.SequenceDelimitationItem) {
_vr = DicomVR.NONE;
_state = ParseState.Length;
break;
}
if (IsExplicitVR) {
if (!source.Require(2, ParseDataset, state)) {
_result = DicomReaderResult.Suspended;
return;
}
byte[] bytes = source.GetBytes(2);
string vr = Encoding.UTF8.GetString(bytes, 0, bytes.Length);
try {
_vr = DicomVR.Parse(vr);
} catch {
// unable to parse VR
_vr = DicomVR.UN;
}
} else {
DicomDictionaryEntry entry = Dictionary[_tag];
if (entry != null) {
if (entry == DicomDictionary.UnknownTag)
_vr = DicomVR.UN;
else if (entry.ValueRepresentations.Contains(DicomVR.OB) && entry.ValueRepresentations.Contains(DicomVR.OW))
_vr = DicomVR.OW; // ???
else
_vr = entry.ValueRepresentations.FirstOrDefault();
}
}
if (_vr == null)
_vr = DicomVR.UN;
_state = ParseState.Length;
if (_vr == DicomVR.UN) {
if (_tag.Element == 0x0000) {
// Group Length to UL
_vr = DicomVR.UL;
break;
} else if (IsExplicitVR) {
break;
}
}
if (_tag.IsPrivate) {
if (_tag.Element != 0x0000 && _tag.Element <= 0x00ff && _vr == DicomVR.UN)
_vr = DicomVR.LO; // force private creator to LO
}
}
while (_state == ParseState.Length) {
if (_tag == DicomTag.Item || _tag == DicomTag.ItemDelimitationItem || _tag == DicomTag.SequenceDelimitationItem) {
if (!source.Require(4, ParseDataset, state)) {
_result = DicomReaderResult.Suspended;
return;
}
_length = source.GetUInt32();
_state = ParseState.Value;
break;
}
if (IsExplicitVR) {
if (_vr.Is16bitLength) {
if (!source.Require(2, ParseDataset, state)) {
_result = DicomReaderResult.Suspended;
return;
}
_length = source.GetUInt16();
} else {
if (!source.Require(6, ParseDataset, state)) {
_result = DicomReaderResult.Suspended;
return;
}
source.Skip(2);
_length = source.GetUInt32();
}
} else {
if (!source.Require(4, ParseDataset, state)) {
_result = DicomReaderResult.Suspended;
return;
}
_length = source.GetUInt32();
// assume that undefined length in implicit dataset is SQ
if (_length == UndefinedLength && _vr == DicomVR.UN)
_vr = DicomVR.SQ;
}
_state = ParseState.Value;
}
if (_state == ParseState.Value) {
// check dictionary for VR after reading length to handle 16-bit lengths
// check before reading value to handle SQ elements
if (_vr == DicomVR.UN && IsExplicitVR) {
var entry = Dictionary[_tag];
if (entry != null)
_vr = entry.ValueRepresentations.FirstOrDefault();
if (_vr == null)
_vr = DicomVR.UN;
}
if (_tag == DicomTag.ItemDelimitationItem) {
// end of sequence item
return;
}
while (_vr == DicomVR.SQ && _tag.IsPrivate) {
if (!IsPrivateSequence(source)) {
_vr = DicomVR.UN;
break;
}
if (IsPrivateSequenceBad(source)) {
_badPrivateSequence = true;
_explicit = !_explicit;
}
break;
}
if (_vr == DicomVR.SQ) {
// start of sequence
_observer.OnBeginSequence(source, _tag, _length);
_state = ParseState.Tag;
if (_length != UndefinedLength) {
_implicit = false;
source.PushMilestone(_length);
} else
_implicit = true;
PushState(state);
ParseItemSequence(source, null);
continue;
}
if (_length == UndefinedLength) {
_observer.OnBeginFragmentSequence(source, _tag, _vr);
_state = ParseState.Tag;
PushState(state);
ParseFragmentSequence(source, null);
continue;
}
if (!source.Require(_length, ParseDataset, state)) {
_result = DicomReaderResult.Suspended;
return;
}
IByteBuffer buffer = source.GetBuffer(_length);
if (!_vr.IsString)
buffer = EndianByteBuffer.Create(buffer, source.Endian, _vr.UnitSize);
_observer.OnElement(source, _tag, _vr, buffer);
// parse private creator value and add to lookup table
if (_tag.IsPrivate && _tag.Element != 0x0000 && _tag.Element <= 0x00ff) {
var creator = DicomEncoding.Default.GetString(buffer.Data, 0, buffer.Data.Length).TrimEnd((char)DicomVR.LO.PaddingValue);
var card = (uint)(_tag.Group << 16) + (uint)(_tag.Element);
_private[card] = creator;
}
ResetState();
}
}
if (source.HasReachedMilestone()) {
// end of explicit length sequence item
source.PopMilestone();
return;
}
if (_result != DicomReaderResult.Processing)
return;
// end of processing
_result = DicomReaderResult.Success;
} catch (Exception e) {
_exception = e;
_result = DicomReaderResult.Error;
} finally {
if (_result != DicomReaderResult.Processing && _result != DicomReaderResult.Suspended) {
_async.Set();
}
}
}
private async Task ParseItemSequenceAsync(IByteSource source)
{
this.result = DicomReaderResult.Processing;
while (!source.IsEOF && !source.HasReachedMilestone())
{
if (!this.ParseItemSequenceTag(source)) return;
if (!await this.ParseItemSequenceValueAsync(source).ConfigureAwait(false)) return;
}
this.ParseItemSequencePostProcess(source);
}
private void ParseDataset(IByteSource source, object state)
{
try {
_result = DicomReaderResult.Processing;
while (!source.IsEOF && !source.HasReachedMilestone() && _result == DicomReaderResult.Processing)
{
if (_state == ParseState.Tag)
{
source.Mark();
if (!source.Require(4, ParseDataset, state))
{
_result = DicomReaderResult.Suspended;
return;
}
ushort group = source.GetUInt16();
ushort element = source.GetUInt16();
DicomPrivateCreator creator = null;
if (group.IsOdd() && element > 0x00ff)
{
string pvt = null;
uint card = (uint)(group << 16) + (uint)(element >> 8);
if (_private.TryGetValue(card, out pvt))
{
creator = Dictionary.GetPrivateCreator(pvt);
}
}
_tag = new DicomTag(group, element, creator);
_entry = Dictionary[_tag];
if (!_tag.IsPrivate && _entry != null && _entry.MaskTag == null)
{
_tag = _entry.Tag; // Use dictionary tag
}
if (_stop != null && _tag.CompareTo(_stop) >= 0)
{
_result = DicomReaderResult.Stopped;
return;
}
_state = ParseState.VR;
}
while (_state == ParseState.VR)
{
if (_tag == DicomTag.Item || _tag == DicomTag.ItemDelimitationItem || _tag == DicomTag.SequenceDelimitationItem)
{
_vr = DicomVR.NONE;
_state = ParseState.Length;
break;
}
if (IsExplicitVR)
{
if (!source.Require(2, ParseDataset, state))
{
_result = DicomReaderResult.Suspended;
return;
}
byte[] bytes = source.GetBytes(2);
string vr = Encoding.UTF8.GetString(bytes, 0, bytes.Length);
if (!DicomVR.TryParse(vr, out _vr))
{
// unable to parse VR
_vr = DicomVR.UN;
}
}
else
{
if (_entry != null)
{
if (_entry == DicomDictionary.UnknownTag)
{
_vr = DicomVR.UN;
}
else if (_entry.ValueRepresentations.Contains(DicomVR.OB) && _entry.ValueRepresentations.Contains(DicomVR.OW))
{
_vr = DicomVR.OW; // ???
}
else
{
_vr = _entry.ValueRepresentations.FirstOrDefault();
}
}
}
if (_vr == null)
{
_vr = DicomVR.UN;
}
_state = ParseState.Length;
if (_vr == DicomVR.UN)
{
if (_tag.Element == 0x0000)
{
// Group Length to UL
_vr = DicomVR.UL;
break;
}
else if (IsExplicitVR)
{
break;
}
}
if (_tag.IsPrivate)
{
if (_tag.Element != 0x0000 && _tag.Element <= 0x00ff && _vr == DicomVR.UN)
{
_vr = DicomVR.LO; // force private creator to LO
}
}
}
while (_state == ParseState.Length)
{
if (_tag == DicomTag.Item || _tag == DicomTag.ItemDelimitationItem || _tag == DicomTag.SequenceDelimitationItem)
{
if (!source.Require(4, ParseDataset, state))
{
_result = DicomReaderResult.Suspended;
return;
}
_length = source.GetUInt32();
_state = ParseState.Value;
break;
}
if (IsExplicitVR)
{
if (_vr.Is16bitLength)
{
if (!source.Require(2, ParseDataset, state))
{
_result = DicomReaderResult.Suspended;
return;
}
_length = source.GetUInt16();
}
else
{
if (!source.Require(6, ParseDataset, state))
{
_result = DicomReaderResult.Suspended;
return;
}
source.Skip(2);
_length = source.GetUInt32();
}
}
else
{
if (!source.Require(4, ParseDataset, state))
{
_result = DicomReaderResult.Suspended;
return;
}
_length = source.GetUInt32();
// assume that undefined length in implicit dataset is SQ
if (_length == UndefinedLength && _vr == DicomVR.UN)
{
_vr = DicomVR.SQ;
}
}
_state = ParseState.Value;
}
if (_state == ParseState.Value)
{
// check dictionary for VR after reading length to handle 16-bit lengths
// check before reading value to handle SQ elements
var parsedVR = _vr;
// check dictionary for VR after reading length to handle 16-bit lengths
// check before reading value to handle SQ elements
if (_vr == DicomVR.UN && IsExplicitVR)
{
var entry = Dictionary[_tag];
if (entry != null)
{
_vr = entry.ValueRepresentations.FirstOrDefault();
}
if (_vr == null)
{
_vr = DicomVR.UN;
}
}
if (_tag == DicomTag.ItemDelimitationItem)
{
// end of sequence item
return;
}
while (_vr == DicomVR.SQ && _tag.IsPrivate)
{
if (!IsPrivateSequence(source))
{
_vr = DicomVR.UN;
break;
}
if (IsPrivateSequenceBad(source))
{
_badPrivateSequence = true;
_explicit = !_explicit;
}
break;
}
if (_vr == DicomVR.SQ)
{
// start of sequence
_observer.OnBeginSequence(source, _tag, _length);
_state = ParseState.Tag;
if (_length != UndefinedLength)
{
_implicit = false;
source.PushMilestone(_length);
}
else
{
_implicit = true;
}
PushState(state);
var last = source.Position;
ParseItemSequence(source, null);
// Aeric Sylvan - https://github.com/rcd/fo-dicom/issues/62#issuecomment-46248073
// Fix reading of SQ with parsed VR of UN
if (source.Position > last || _length == 0)
{
continue;
}
else
{
_state = ParseState.Value;
_vr = parsedVR;
}
}
if (_length == UndefinedLength)
{
_observer.OnBeginFragmentSequence(source, _tag, _vr);
_state = ParseState.Tag;
PushState(state);
ParseFragmentSequence(source, null);
continue;
}
if (!source.Require(_length, ParseDataset, state))
{
_result = DicomReaderResult.Suspended;
return;
}
IByteBuffer buffer = source.GetBuffer(_length);
if (!_vr.IsString)
{
buffer = EndianByteBuffer.Create(buffer, source.Endian, _vr.UnitSize);
}
_observer.OnElement(source, _tag, _vr, buffer);
// parse private creator value and add to lookup table
if (_tag.IsPrivate && _tag.Element != 0x0000 && _tag.Element <= 0x00ff)
{
var creator = DicomEncoding.Default.GetString(buffer.Data, 0, buffer.Data.Length).TrimEnd((char)DicomVR.LO.PaddingValue);
var card = (uint)(_tag.Group << 16) + (uint)(_tag.Element);
_private[card] = creator;
}
ResetState();
}
}
if (source.HasReachedMilestone())
{
// end of explicit length sequence item
source.PopMilestone();
return;
}
if (_result != DicomReaderResult.Processing)
{
return;
}
// end of processing
_result = DicomReaderResult.Success;
} catch (Exception e) {
_exception = e;
_result = DicomReaderResult.Error;
} finally {
if (_result != DicomReaderResult.Processing && _result != DicomReaderResult.Suspended)
{
_async.Set();
}
}
}
private bool ParseItemSequenceTag(IByteSource source)
{
if (this.parseStage == ParseStage.Tag)
{
source.Mark();
if (!source.Require(8))
{
this.result = DicomReaderResult.Suspended;
return false;
}
var group = source.GetUInt16();
var element = source.GetUInt16();
this._tag = new DicomTag(@group, element);
if (this._tag != DicomTag.Item && this._tag != DicomTag.SequenceDelimitationItem)
{
// assume invalid sequence
source.Rewind();
if (!this._implicit)
{
source.PopMilestone();
}
this.observer.OnEndSequence();
if (this.badPrivateSequence)
{
this.isExplicitVR = !this.isExplicitVR;
this.badPrivateSequence = false;
}
return false;
}
this.length = source.GetUInt32();
if (this._tag == DicomTag.SequenceDelimitationItem)
{
// #64, in case explicit length has been specified despite occurrence of Sequence Delimitation Item
if (source.HasReachedMilestone() && source.MilestonesCount > this.sequenceDepth)
{
this.ResetState();
return true;
}
// end of sequence
this.observer.OnEndSequence();
if (this.badPrivateSequence)
{
this.isExplicitVR = !this.isExplicitVR;
this.badPrivateSequence = false;
}
this.ResetState();
return false;
}
this.parseStage = ParseStage.Value;
}
return true;
}
