/// <summary>
/// Function to decode data in this section.
/// </summary>
/// <param name="tables">Huffman table to use during deconding</param>
/// <param name="length">nr of samples in encoded data</param>
/// <returns>decoded leads</returns>
public short[][] DecodeData(SCPSection2 tables, ushort length)
{
if (Works() &&
(tables != null))
{
// Reset selected table.
tables.ResetSelect();
short[][] leads = new short[_Data.Length][];
for (int loper = 0; loper < _Data.Length; loper++)
{
leads[loper] = tables.Decode(_Data[loper], 0, _Data[loper].Length, (ushort)((length * 1000) / _TimeInterval), _Difference);
// Check if lead was decoded
if (leads[loper] == null)
{
// return if lead decode failed.
return(null);
}
}
return(leads);
}
return(null);
}
/// <summary>
/// Function to decode data in this section.
/// </summary>
/// <param name="tables">Huffman table to use during deconding</param>
/// <param name="leadDefinition"></param>
/// <returns>decoded leads</returns>
public short[][] DecodeData(SCPSection2 tables, SCPSection3 leadDefinition, SCPSection4 qrsLocations, int medianFreq)
{
int localFreq = getSamplesPerSecond();
if (Works() &&
(tables != null) &&
(tables.Works()) &&
(leadDefinition != null) &&
(leadDefinition.Works()) &&
(leadDefinition.getNrLeads() == _Data.Length) &&
(localFreq > 0))
{
if ((medianFreq <= 0) ||
(medianFreq == localFreq))
{
medianFreq = 1;
localFreq = 1;
}
if ((medianFreq < localFreq) &&
!leadDefinition.isMediansUsed() &&
(_Bimodal == 0x0))
{
medianFreq = localFreq;
}
if (((medianFreq % localFreq) != 0) ||
((medianFreq / localFreq) < 1) ||
((medianFreq / localFreq) > 4))
{
// make an exception for ECGs that don't use compression (like corpuls ECGs that are in violation of this rule).
if (_Bimodal == 0x0)
{
medianFreq = localFreq;
}
else
{
return(null);
}
}
if ((_Bimodal == 0x1) &&
(qrsLocations == null))
{
return(null);
}
// Reset selected table.
tables.ResetSelect();
short[][] leads = new short[_Data.Length][];
for (int loper = 0; loper < _Data.Length; loper++)
{
int time = (leadDefinition.getLeadLength(loper) * localFreq) / medianFreq;
// Bimodal part might be buggy unable to test.
if ((localFreq != medianFreq) &&
(_Bimodal == 0x1))
{
int rate = medianFreq / localFreq;
// Calculate nr of samples stored in section.
time = 0;
int nrzones = qrsLocations.getNrProtectedZones();
for (int zone = 0; zone < nrzones; zone++)
{
int begin = (qrsLocations.getProtectedStart(zone) >= leadDefinition.getLeadStart(loper) ? qrsLocations.getProtectedStart(zone) : leadDefinition.getLeadStart(loper));
int end = (qrsLocations.getProtectedEnd(zone) <= leadDefinition.getLeadEnd(loper) ? qrsLocations.getProtectedEnd(zone) : leadDefinition.getLeadEnd(loper));
begin = (end > begin ? end - begin + 1 : 0);
time += begin + (rate - (begin % rate));
}
time += ((leadDefinition.getLeadLength(loper) - time) * localFreq) / medianFreq;
}
leads[loper] = tables.Decode(_Data[loper], 0, _Data[loper].Length, time, _Difference);
// Check if lead was decoded
if (leads[loper] == null)
{
// return if lead decode failed.
return(null);
}
if (localFreq != medianFreq)
{
int rate = medianFreq / localFreq;
if (_Bimodal == 0x1)
{
int beginNonProtected = 0;
int endNonProtected = qrsLocations.getProtectedStart(0);
// Restructure bimodal data to length set in Section3.
short[] temp = new short[leadDefinition.getLeadLength(loper)];
int time1Offset = leadDefinition.getLeadStart(loper);
int time1 = 0;
int time2 = 0;
int zone = 0;
while ((time1 < temp.Length) &&
(time2 < leads[loper].Length))
{
if (((time1 + time1Offset) >= beginNonProtected) &&
((time1 + time1Offset) < endNonProtected))
{
for (int begin = 0; begin < (rate >> 1); begin++)
{
temp[time1++] = leads[loper][time2];
}
if ((time2 + ((endNonProtected - (time1 + time1Offset)) / rate)) >= leads[loper].Length)
{
endNonProtected -= ((time2 + ((endNonProtected - (time1 + time1Offset)) / rate)) - leads[loper].Length) * rate;
}
endNonProtected -= rate + (rate >> 1);
while ((time1 + time1Offset) < endNonProtected)
{
for (int i = 0; (i < rate) && (time1 < temp.Length); i++)
{
temp[time1++] = (short)(((leads[loper][time2 + 1] - leads[loper][time2]) / rate) * i + leads[loper][time2]);
}
time2++;
}
endNonProtected += rate + (rate >> 1);
for (int end = 0; end < (rate >> 1); end++)
{
temp[time1++] = leads[loper][time2];
}
time2++;
beginNonProtected = (zone == qrsLocations.getNrProtectedZones() ? temp.Length : qrsLocations.getProtectedEnd(zone));
}
else
{
// This should never happen!!
if (zone == qrsLocations.getNrProtectedZones())
{
break;
}
while (((time1 + time1Offset) < qrsLocations.getProtectedEnd(zone)) &&
(time1 < temp.Length) &&
(time2 < leads[loper].Length))
{
temp[time1++] = leads[loper][time2++];
}
zone++;
endNonProtected = (zone == qrsLocations.getNrProtectedZones() ? temp.Length : qrsLocations.getProtectedStart(zone));
}
}
leads[loper] = temp;
}
else
{
ECGTool.ResampleLead(leads[loper], localFreq, medianFreq, out leads[loper]);
}
}
}
return(leads);
}
return(null);
}
