public static void Write(DICOMBinaryWriter dw, VR vr, DICOMWriteSettings settings, int length)
{
var lengthBytes = BitConverter.GetBytes(length);
if (settings.TransferSyntax != TransferSyntax.IMPLICIT_VR_LITTLE_ENDIAN)
{
switch (VRDictionary.GetEncodingFromVR(vr))
{
case VREncoding.ExplicitLong:
dw.WriteNullBytes(2);
lengthBytes = BitConverter.GetBytes(length);
break;
case VREncoding.ExplicitShort:
lengthBytes = BitConverter.GetBytes((ushort)length);
if (length > 65536)
{
throw new ArgumentOutOfRangeException(
"Length is greater than allowed for explicit VR syntax. Try using implicit VR");
}
break;
case VREncoding.Implicit:
lengthBytes = BitConverter.GetBytes(length);
break;
}
}
if (settings.TransferSyntax == TransferSyntax.EXPLICIT_VR_BIG_ENDIAN)
{
Array.Reverse(lengthBytes);
}
dw.Write(lengthBytes);
}
public static void Write(DICOMBinaryWriter dw, VR vr, DICOMWriteSettings settings, int length)
{
var lengthBytes = new byte[0];
if (!(settings.TransferSyntax == TransferSyntax.IMPLICIT_VR_LITTLE_ENDIAN))
{
switch (VRDictionary.GetEncodingFromVR(vr))
{
case VREncoding.ExplicitLong:
dw.WriteNullBytes(2);
lengthBytes = BitConverter.GetBytes(length);
break;
case VREncoding.ExplicitShort:
lengthBytes = BitConverter.GetBytes((ushort)length);
break;
case VREncoding.Implicit:
lengthBytes = BitConverter.GetBytes(length);
break;
}
}
else if (settings.TransferSyntax == TransferSyntax.EXPLICIT_VR_BIG_ENDIAN)
{
lengthBytes = BitConverter.GetBytes(length);
lengthBytes.Reverse();
}
else
{
//Explicit VR Little Endian
lengthBytes = BitConverter.GetBytes(length);
}
dw.Write(lengthBytes);
}
/// <summary>
/// Reads the length in big endian byte format from a series of bytes in a stream. The number of bytes is automatically
/// determined from
/// VR.
/// </summary>
/// <param name="vr">the value representation of the element</param>
/// <param name="dr">the binary stream with a current position on the length parameter</param>
/// <returns></returns>
public static int ReadBigEndian(VR vr, DICOMBinaryReader dr)
{
byte[] bytes = null;
switch (VRDictionary.GetEncodingFromVR(vr))
{
case VREncoding.Implicit:
bytes = dr.ReadBytes(4);
break;
case VREncoding.ExplicitLong:
bytes = dr.Skip(2).ReadBytes(4);
break;
case VREncoding.ExplicitShort:
bytes = dr.ReadBytes(2);
break;
}
return(ReadBigEndian(bytes));
}
public static int PeekBigEndian(VR vr, DICOMBinaryReader dr)
{
var bytes = new byte[0];
switch (VRDictionary.GetEncodingFromVR(vr))
{
case VREncoding.Implicit:
bytes = dr.Peek(4);
break;
case VREncoding.ExplicitLong:
bytes = dr.Peek(6).Skip(2).Take(4).ToArray();
break;
case VREncoding.ExplicitShort:
bytes = dr.Peek(2);
break;
}
return(ReadBigEndian(bytes));;
}
/// <summary>
/// Reads the length in little endian byte format from a series of bytes in a stream. The number of bytes is
/// automatically determined from
/// VR.
/// </summary>
/// <param name="vr">the value representation of the element</param>
/// <param name="dr">the binary stream with a current position on the length parameter</param>
/// <returns></returns>
public static int ReadLittleEndian(VR vr, DICOMBinaryReader dr)
{
int length = 0;
switch (VRDictionary.GetEncodingFromVR(vr))
{
case VREncoding.Implicit:
byte[] byteLength = dr.ReadBytes(4);
length = BitConverter.ToInt32(byteLength, 0);
break;
case VREncoding.ExplicitLong:
byteLength = dr.Skip(2).ReadBytes(4);
length = BitConverter.ToInt32(byteLength, 0);
break;
case VREncoding.ExplicitShort:
byteLength = dr.ReadBytes(2);
length = BitConverter.ToUInt16(byteLength, 0);
break;
}
return(length);
}
public static int PeekLittleEndian(VR vr, DICOMBinaryReader dr)
{
var length = 0;
switch (VRDictionary.GetEncodingFromVR(vr))
{
case VREncoding.Implicit:
var byteLength = dr.Peek(4);
length = BitConverter.ToInt32(byteLength, 0);
break;
case VREncoding.ExplicitLong:
byteLength = dr.Peek(6).Skip(2).Take(4).ToArray();
length = BitConverter.ToInt32(byteLength, 0);
break;
case VREncoding.ExplicitShort:
byteLength = dr.Peek(2);
length = BitConverter.ToUInt16(byteLength, 0);
break;
}
return(length);
}
