private void ParsePreamble(IByteSource source, object state)
{
try {
if (!source.Require(132, ParsePreamble, state))
{
return;
}
_source.Skip(128);
if (_source.GetUInt8() != 'D' ||
_source.GetUInt8() != 'I' ||
_source.GetUInt8() != 'C' ||
_source.GetUInt8() != 'M')
{
throw new DicomReaderException("Invalid preamble found in DICOM file parser");
}
DicomReaderCallbackObserver obs = new DicomReaderCallbackObserver();
obs.Add(DicomTag.TransferSyntaxUID, delegate(object sender, DicomReaderEventArgs ea) {
try {
string uid = Encoding.ASCII.GetString(ea.Data.Data);
_syntax = DicomTransferSyntax.Parse(uid);
} catch {
}
});
_source.Endian = _syntax.Endian;
_reader.IsExplicitVR = _syntax.IsExplicitVR;
_reader.BeginRead(_source, new DicomReaderMultiObserver(obs, _fmiObserver), FileMetaInfoStopTag, OnFileMetaInfoParseComplete, null);
} catch (Exception e) {
if (_exception == null)
{
_exception = e;
}
_result = DicomReaderResult.Error;
} finally {
if (_result != DicomReaderResult.Processing && _result != DicomReaderResult.Suspended)
{
_async.Set();
}
}
}
private static async Task <Tuple <DicomReaderResult, DicomFileFormat, DicomTransferSyntax> > DoParseAsync(
IByteSource source,
IDicomReaderObserver fileMetasetInfoObserver,
IDicomReaderObserver datasetObserver,
Func <ParseState, bool> stop,
DicomTransferSyntax syntax,
DicomFileFormat fileFormat)
{
string code = null, uid = null;
var obs = new DicomReaderCallbackObserver();
if (fileFormat != DicomFileFormat.DICOM3)
{
obs.Add(
DicomTag.RecognitionCodeRETIRED,
(sender, ea) =>
{
try
{
code = Encoding.UTF8.GetString(ea.Data.Data, 0, ea.Data.Data.Length);
}
catch
{
}
});
}
obs.Add(
DicomTag.TransferSyntaxUID,
(sender, ea) =>
{
try
{
uid = Encoding.UTF8.GetString(ea.Data.Data, 0, ea.Data.Data.Length);
}
catch
{
}
});
var reader = new DicomReader {
IsExplicitVR = syntax.IsExplicitVR, IsDeflated = false
};
DicomReaderResult result;
if (fileFormat == DicomFileFormat.DICOM3NoFileMetaInfo)
{
result =
await
reader.ReadAsync(source, new DicomReaderMultiObserver(obs, datasetObserver), stop).ConfigureAwait(false);
UpdateFileFormatAndSyntax(code, uid, ref fileFormat, ref syntax);
}
else
{
if (
await
reader.ReadAsync(
source,
new DicomReaderMultiObserver(obs, fileMetasetInfoObserver),
_FileMetaInfoStopCriterion).ConfigureAwait(false) != DicomReaderResult.Stopped)
{
throw new DicomReaderException("DICOM File Meta Info ended prematurely");
}
UpdateFileFormatAndSyntax(code, uid, ref fileFormat, ref syntax);
// rewind to last marker (start of previous tag)... ugly because
// it requires knowledge of how the parser is implemented
source.Rewind();
source.Endian = syntax.Endian;
reader.IsExplicitVR = syntax.IsExplicitVR;
reader.IsDeflated = syntax.IsDeflate;
result = await reader.ReadAsync(source, datasetObserver, stop).ConfigureAwait(false);
}
return(Tuple.Create(result, fileFormat, syntax));
}
private static async Task<Tuple<DicomReaderResult, DicomFileFormat, DicomTransferSyntax>> DoParseAsync(
IByteSource source,
IDicomReaderObserver fileMetasetInfoObserver,
IDicomReaderObserver datasetObserver,
Func<ParseState, bool> stop,
DicomTransferSyntax syntax,
DicomFileFormat fileFormat)
{
string code = null, uid = null;
var obs = new DicomReaderCallbackObserver();
if (fileFormat != DicomFileFormat.DICOM3)
{
obs.Add(
DicomTag.RecognitionCodeRETIRED,
(sender, ea) =>
{
try
{
code = Encoding.UTF8.GetString(ea.Data.Data, 0, ea.Data.Data.Length);
}
catch
{
}
});
}
obs.Add(
DicomTag.TransferSyntaxUID,
(sender, ea) =>
{
try
{
uid = Encoding.UTF8.GetString(ea.Data.Data, 0, ea.Data.Data.Length);
}
catch
{
}
});
var reader = new DicomReader { IsExplicitVR = syntax.IsExplicitVR, IsDeflated = false };
DicomReaderResult result;
if (fileFormat == DicomFileFormat.DICOM3NoFileMetaInfo)
{
result =
await
reader.ReadAsync(source, new DicomReaderMultiObserver(obs, datasetObserver), stop).ConfigureAwait(false);
UpdateFileFormatAndSyntax(code, uid, ref fileFormat, ref syntax);
}
else
{
if (
await
reader.ReadAsync(
source,
new DicomReaderMultiObserver(obs, fileMetasetInfoObserver),
FileMetaInfoStopCriterion).ConfigureAwait(false) != DicomReaderResult.Stopped)
{
throw new DicomReaderException("DICOM File Meta Info ended prematurely");
}
UpdateFileFormatAndSyntax(code, uid, ref fileFormat, ref syntax);
// rewind to last marker (start of previous tag)... ugly because
// it requires knowledge of how the parser is implemented
source.Rewind();
source.Endian = syntax.Endian;
reader.IsExplicitVR = syntax.IsExplicitVR;
reader.IsDeflated = syntax.IsDeflate;
result = await reader.ReadAsync(source, datasetObserver, stop).ConfigureAwait(false);
}
return Tuple.Create(result, fileFormat, syntax);
}
private void ParsePreamble(IByteSource source, object state) {
try {
if (!source.Require(132, ParsePreamble, state))
return;
// mark file origin
_source.Mark();
// test for DICM preamble
_source.Skip(128);
if (_source.GetUInt8() == 'D' &&
_source.GetUInt8() == 'I' &&
_source.GetUInt8() == 'C' &&
_source.GetUInt8() == 'M')
_fileFormat = DicomFileFormat.DICOM3;
// test for incorrect syntax in file meta info
do {
if (_fileFormat == DicomFileFormat.DICOM3) {
// move milestone to after preamble
_source.Mark();
} else {
// rewind to origin milestone
_source.Rewind();
}
// test for file meta info
var group = _source.GetUInt16();
if (group > 0x00ff) {
_source.Endian = Endian.Big;
_syntax = DicomTransferSyntax.ExplicitVRBigEndian;
group = Endian.Swap(group);
}
if (group > 0x00ff) {
// invalid starting tag
_fileFormat = DicomFileFormat.Unknown;
_source.Rewind();
break;
}
if (_fileFormat == DicomFileFormat.Unknown) {
if (group == 0x0002)
_fileFormat = DicomFileFormat.DICOM3NoPreamble;
else
_fileFormat = DicomFileFormat.DICOM3NoFileMetaInfo;
}
var element = _source.GetUInt16();
var tag = new DicomTag(group, element);
// test for explicit VR
var vrt = Encoding.UTF8.GetBytes(tag.DictionaryEntry.ValueRepresentations[0].Code);
var vrs = _source.GetBytes(2);
if (vrt[0] != vrs[0] || vrt[1] != vrs[1]) {
// implicit VR
if (_syntax.Endian == Endian.Little)
_syntax = DicomTransferSyntax.ImplicitVRLittleEndian;
else
_syntax = DicomTransferSyntax.ImplicitVRBigEndian;
}
_source.Rewind();
} while (_fileFormat == DicomFileFormat.Unknown);
if (_fileFormat == DicomFileFormat.Unknown)
throw new DicomReaderException("Attempted to read invalid DICOM file");
var obs = new DicomReaderCallbackObserver();
if (_fileFormat != DicomFileFormat.DICOM3) {
obs.Add(DicomTag.RecognitionCodeRETIRED, (object sender, DicomReaderEventArgs ea) => {
try {
string code = Encoding.UTF8.GetString(ea.Data.Data, 0, ea.Data.Data.Length);
if (code == "ACR-NEMA 1.0")
_fileFormat = DicomFileFormat.ACRNEMA1;
else if (code == "ACR-NEMA 2.0")
_fileFormat = DicomFileFormat.ACRNEMA2;
} catch {
}
});
}
obs.Add(DicomTag.TransferSyntaxUID, (object sender, DicomReaderEventArgs ea) => {
try {
string uid = Encoding.UTF8.GetString(ea.Data.Data, 0, ea.Data.Data.Length);
_syntax = DicomTransferSyntax.Parse(uid);
} catch {
}
});
_source.Endian = _syntax.Endian;
_reader.IsExplicitVR = _syntax.IsExplicitVR;
if (_fileFormat == DicomFileFormat.DICOM3NoFileMetaInfo)
_reader.BeginRead(_source, new DicomReaderMultiObserver(obs, _dataObserver), null, OnDatasetParseComplete, null);
else
_reader.BeginRead(_source, new DicomReaderMultiObserver(obs, _fmiObserver), FileMetaInfoStopTag, OnFileMetaInfoParseComplete, null);
} catch (Exception e) {
if (_exception == null)
_exception = e;
_result = DicomReaderResult.Error;
} finally {
if (_result != DicomReaderResult.Processing && _result != DicomReaderResult.Suspended) {
_async.Set();
}
}
}
private void ParsePreamble(IByteSource source, object state)
{
try {
if (!source.Require(132, ParsePreamble, state))
{
return;
}
// mark file origin
_source.Mark();
// test for DICM preamble
_source.Skip(128);
if (_source.GetUInt8() == 'D' &&
_source.GetUInt8() == 'I' &&
_source.GetUInt8() == 'C' &&
_source.GetUInt8() == 'M')
{
_fileFormat = DicomFileFormat.DICOM3;
}
// test for incorrect syntax in file meta info
do
{
if (_fileFormat == DicomFileFormat.DICOM3)
{
// move milestone to after preamble
_source.Mark();
}
else
{
// rewind to origin milestone
_source.Rewind();
}
// test for file meta info
var group = _source.GetUInt16();
if (group > 0x00ff)
{
_source.Endian = Endian.Big;
_syntax = DicomTransferSyntax.ExplicitVRBigEndian;
group = Endian.Swap(group);
}
if (group > 0x00ff)
{
// invalid starting tag
_fileFormat = DicomFileFormat.Unknown;
_source.Rewind();
break;
}
if (_fileFormat == DicomFileFormat.Unknown)
{
if (group == 0x0002)
{
_fileFormat = DicomFileFormat.DICOM3NoPreamble;
}
else
{
_fileFormat = DicomFileFormat.DICOM3NoFileMetaInfo;
}
}
var element = _source.GetUInt16();
var tag = new DicomTag(group, element);
// test for explicit VR
var vrt = Encoding.ASCII.GetBytes(tag.DictionaryEntry.ValueRepresentations[0].Code);
var vrs = _source.GetBytes(2);
if (vrt[0] != vrs[0] || vrt[1] != vrs[1])
{
// implicit VR
if (_syntax.Endian == Endian.Little)
{
_syntax = DicomTransferSyntax.ImplicitVRLittleEndian;
}
else
{
_syntax = DicomTransferSyntax.ImplicitVRBigEndian;
}
}
_source.Rewind();
} while (_fileFormat == DicomFileFormat.Unknown);
if (_fileFormat == DicomFileFormat.Unknown)
{
throw new DicomReaderException("Attempted to read invalid DICOM file");
}
var obs = new DicomReaderCallbackObserver();
if (_fileFormat != DicomFileFormat.DICOM3)
{
obs.Add(DicomTag.RecognitionCodeRETIRED, (object sender, DicomReaderEventArgs ea) => {
try {
string code = Encoding.ASCII.GetString(ea.Data.Data);
if (code == "ACR-NEMA 1.0")
{
_fileFormat = DicomFileFormat.ACRNEMA1;
}
else if (code == "ACR-NEMA 2.0")
{
_fileFormat = DicomFileFormat.ACRNEMA2;
}
} catch {
}
});
}
obs.Add(DicomTag.TransferSyntaxUID, (object sender, DicomReaderEventArgs ea) => {
try {
string uid = Encoding.ASCII.GetString(ea.Data.Data);
_syntax = DicomTransferSyntax.Parse(uid);
} catch {
}
});
_source.Endian = _syntax.Endian;
_reader.IsExplicitVR = _syntax.IsExplicitVR;
if (_fileFormat == DicomFileFormat.DICOM3NoFileMetaInfo)
{
_reader.BeginRead(_source, new DicomReaderMultiObserver(obs, _dataObserver), null, OnDatasetParseComplete, null);
}
else
{
_reader.BeginRead(_source, new DicomReaderMultiObserver(obs, _fmiObserver), FileMetaInfoStopTag, OnFileMetaInfoParseComplete, null);
}
} catch (Exception e) {
if (_exception == null)
{
_exception = e;
}
_result = DicomReaderResult.Error;
} finally {
if (_result != DicomReaderResult.Processing && _result != DicomReaderResult.Suspended)
{
_async.Set();
}
}
}
private void ParsePreamble(IByteSource source, object state)
{
try {
if (!source.Require(132, ParsePreamble, state))
return;
_source.Skip(128);
if (_source.GetUInt8() != 'D' ||
_source.GetUInt8() != 'I' ||
_source.GetUInt8() != 'C' ||
_source.GetUInt8() != 'M')
throw new DicomReaderException("Invalid preamble found in DICOM file parser");
DicomReaderCallbackObserver obs = new DicomReaderCallbackObserver();
obs.Add(DicomTag.TransferSyntaxUID, delegate(object sender, DicomReaderEventArgs ea) {
try {
string uid = Encoding.ASCII.GetString(ea.Data.Data);
_syntax = DicomTransferSyntax.Parse(uid);
} catch {
}
});
_source.Endian = _syntax.Endian;
_reader.IsExplicitVR = _syntax.IsExplicitVR;
_reader.BeginRead(_source, new DicomReaderMultiObserver(obs, _fmiObserver), FileMetaInfoStopTag, OnFileMetaInfoParseComplete, null);
} catch (Exception e) {
if (_exception == null)
_exception = e;
_result = DicomReaderResult.Error;
} finally {
if (_result != DicomReaderResult.Processing && _result != DicomReaderResult.Suspended) {
_async.Set();
}
}
}