/// <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); }