private bool ReadBuffer()
{
string errMsg = null;
Wfdb.WFDB_SampleArray frameData = null;
bool result = WfdbAccess.GetSignalFrame(ref frameData, siArray, numSignals, ref errMsg);
if (result && (frameData.getitem(0) == 0))
{ // Something weird!
errMsg = null; // just for a flag
}
if (!result)
{
MessageBox.Show(errMsg);
doneReading = true; // give up actual reading
return(false);
}
// No error -- read frame data into buffer:
for (int samp = 0; samp < buffSize; samp++)
{
frameBuffer[samp] = frameData.getitem(samp);
//if (frameBuffer[samp] == 0)
//{ // Something weird!
// result = false; // just for a flag
//}
}
// And, reset buffer pointer
bufferPointer = 0;
return(true);
}
/*
* /// <summary>
* /// Minimal constructor. Note that if you use this constructor, you must set
* /// recordName before calling init(), otherwise an exception will be raised.
* /// </summary>
* /// <param name="secondsPerStep">Interval between samples, in seconds or fraction thereof,
* /// e.g. 1 KHz = 1 ms per sample would have secondsPerStep = 0.001. If
* /// autoOutput is TRUE and the file header has its own sample period value,
* /// then this param is ignored and the value in the file header is used
* /// instead.</param>
* /// <param name="autoOutput">If TRUE, then we push data out to the Followers AND try to
* /// use the sample period value from the file header; if FALSE, we wait
* /// for whoever to pull out the data.</param>
* public WfdbReader ( double secondsPerStep, bool autoOutput )
* : base ( secondsPerStep, autoOutput )
* { // Nothing to do.
* }
* // */
/// <summary>
/// Full constructor: requires a record name and an optional path.
/// </summary>
/// [param name="secondsPerStep">Interval between samples, in seconds or fraction thereof,
/// e.g. 1 KHz = 1 ms per sample would have secondsPerStep = 0.001. If
/// autoOutput is TRUE and the file header has its own sample period value,
/// then this param is ignored and the value in the file header is used
/// instead.[/param>
/// <param name="autoOutput">If TRUE, then we push data out to the Followers AND try to
/// use the sample period value from the file header; if FALSE, we wait
/// for whoever to pull out the data.</param>
/// <param name="path">A search path for the record; if null, then the default path is used.</param>
/// <param name="rName">Must be an existing record name within the path.</param>
public WfdbReader(/* double secondsPerStep, */ bool autoOutput,
string path, string rName)
: base(/*secondsPerStep*/ 1, autoOutput)
{
string errMsg = "";
// Save values:
searchPath = path.Trim();
recordName = rName.Trim();
// Try the path and record name:
if (searchPath != null)
{
WfdbAccess.SetSearchPath(searchPath);
}
sampFreq = WfdbAccess.GetSamplingFrequency(recordName);
if (sampFreq < 1)
{ // Problem reading header!
//System.Windows.Forms.MessageBox("Unable to access record '" + recordName + "' in path '" + searchPath + "'!");
Exception ex = new ArgumentException("Unable to access header for record '" + recordName + "' in path '" + searchPath + "'.");
throw ex;
}
else
{ // Set secondsPerStep:
this.stepSize = 1 / sampFreq;
}
numSignals = WfdbAccess.GetSignalCount(recordName, ref errMsg);
if (numSignals < 1)
{
//System.Windows.Forms.MessageBox("Unable to access record '" + recordName + "' in path '" + searchPath + "'!");
Exception ex = new ArgumentException("Unable to access record '" + recordName + "' in path '" + searchPath + "'.");
throw ex;
}
}
private void GoToPositionInFile(long samps, ref string errMsg)
{
if (samps > (int)samps)
{ // out of range -- go to max. int. val.:
samps = Int32.MaxValue;
}
WfdbAccess.Seek((int)samps, ref errMsg);
// Adjust cur-pos reference:
dispSamples = samps;
}
/// <summary>
/// Releases all Wfdb-related resources.
/// </summary>
public void ReleaseWfdb()
{ // Release as needed:
WfdbAccess.CloseWfdb();
}
/// <summary>
/// Override default behavior to:
/// - Save a local copy
/// - Get file header info
/// - Update iData accordingly
/// - Allow using header info to drive the output rates.
/// <para>NOTE: This method call GC.Collect() to force garbage collection on the
/// managed-code environment. If you are running unmanaged code, before calling
/// this method you must ensure that your unmanaged storage allocations are properly
/// protected or released.</para>
/// </summary>
public override void init(ChainInfo iData)
{
string errMsg = null;
// Reset THOROUGHLY:
GC.Collect();
GC.WaitForPendingFinalizers();
WfdbAccess.CloseWfdb();
GC.Collect();
GC.WaitForPendingFinalizers();
// Read record header:
siArray = WfdbAccess.GetSigInfoArray(numSignals, ref errMsg);
bool result = WfdbAccess.GetSignalInfo(recordName, siArray, numSignals, ref errMsg);
if (!result)
{
//System.Windows.Forms.MessageBox("Unable to access header for record '" + recordName + "' in path '" + searchPath + "'!");
Exception ex = new ArgumentException("Unable to access header for record '" + recordName + "' in path '" + searchPath + "'.");
throw ex;
}
// Read useful info from header:
WFDB_Siginfo sigInfo = siArray.getitem(0);
buffSize = sigInfo.spf;
frameBuffer = new int[buffSize];
numSamples = sigInfo.nsamp * sigInfo.spf;
sigName = sigInfo.desc;
//sampFreq = WfdbAccess.GetSamplingFrequency(recordName);
//if (sampFreq < 1)
//{ // Problem reading header!
// //System.Windows.Forms.MessageBox("Unable to access record '" + recordName + "' in path '" + searchPath + "'!");
// Exception ex = new ArgumentException("Unable to access header for record '" + recordName + "' in path '" + searchPath + "'.");
// throw ex;
//}
adcZeroRef = sigInfo.adczero;
adcResBits = sigInfo.adcres;
adcMaxValue = (int)Math.Pow(2, adcResBits);
baseline = sigInfo.baseline;
ampGain = sigInfo.gain;
if (ampGain == 0)
{ // Use default:
ampGain = 200;
}
dataUnits = sigInfo.units;
if ((dataUnits == null) || (dataUnits.Length == 0))
{ // Assign arbitrarily?
dataUnits = "mV";
}
// Save a local handle:
if (autoSend)
{ // Point to the input data structure:
initValues = iData;
}
else
{ // Make our own data structure:
initValues = new ChainInfo();
initValues.samplingPeriodSec = iData.samplingPeriodSec;
}
if (autoSend && doneReading) // We previously terminated the timer - restart it:
{ // Init the TimerThread:
sendTimer = new TimerThread(
new System.Threading.ThreadStart(this.next),
true);
}
// Init. what needs it:
dispSamples = 0; // just started, nothing retrieved yet
doneReading = false;
if (initValues.patientInfo == null)
{
initValues.patientInfo = new PatientInfo("", "", "");
}
if (initValues.dataInfo == null)
{
initValues.dataInfo = new DataInfo(sigInfo.desc, DateTime.Now.ToString());
}
// And, apply the REAL values:
initValues.dataInfo.BitsPerSample = adcResBits;
initValues.dataInfo.ScaleMultiplier = ampGain.ToString();
if (adcResBits == 0)
{ // Missing some info -- go with a default:
initValues.dataInfo.FullScaleReferenceVoltage = "2.0";
initValues.dataInfo.ZeroOffset = "0.0";
initValues.dataInfo.ZeroReferenceVoltage = "-2.0";
}
else
{
initValues.dataInfo.FullScaleReferenceVoltage = ((adcMaxValue - baseline) / ampGain).ToString();
initValues.dataInfo.ZeroOffset = baseline.ToString();
initValues.dataInfo.ZeroReferenceVoltage = (-baseline / ampGain).ToString();
}
initValues.dataInfo.ValueUnits = dataUnits;
if (initValues.fileInfo == null)
{
initValues.fileInfo = new FileHandler();
}
if (initValues.samplingPeriodSec != stepSize)
{
// Update the sampling period:
initValues.samplingPeriodSec = stepSize;
}
//// Init. the sampling period:
//this.stepSize = initValues.samplingPeriodSec;
// Init output buffer:
ReadBuffer();
// Apply values and propagate downstream:
base.init(iData); // iData may have been changed or not
}
