private void btnReadBCI2000_Click(object sender, EventArgs e)
{
// clear the output
txtOutput.Text = "";
// try to read the file
Data_BCI2000 info = new Data_BCI2000();
double[][] samples = null;
bool result = readBCI2000dat(txtInputFile.Text, out info, out samples);
if (!result)
{
return;
}
// output
txtOutput.Text = info.firstLine + Environment.NewLine + Environment.NewLine;
txtOutput.Text += "Header length: " + info.headerLen + Environment.NewLine;
txtOutput.Text += "Source channels: " + info.sourceCh + Environment.NewLine;
txtOutput.Text += "State vector length: " + info.stateVectorLen + Environment.NewLine;
txtOutput.Text += Environment.NewLine;
//txtOutput.Text += "Header: " + Environment.NewLine + data.header;
txtOutput.Text += "Sample rate: " + info.samplingRate + Environment.NewLine;
txtOutput.Text += Environment.NewLine;
txtOutput.Text += "Number of samples: " + info.numSamples + Environment.NewLine + Environment.NewLine;
string strOutput = "";
for (int i = 0; i < info.numSamples; i++)
{
for (int j = 0; j < info.sourceCh; j++)
{
if (j != 0)
{
strOutput += "\t";
}
strOutput += samples[i][j];
}
strOutput += Environment.NewLine;
}
txtOutput.Text += strOutput;
}
private bool readBCI2000dat(string filename, out Data_BCI2000 info, out double[][] samples)
{
FileStream dataStream = null;
StreamReader dataReader = null;
// check if the file exists
if (!File.Exists(filename))
{
MessageBox.Show("Could not find input file", "File error", MessageBoxButtons.OK, MessageBoxIcon.Error);
info = null;
samples = null;
return(false);
}
try {
// open file stream
dataStream = new FileStream(filename, FileMode.Open);
// open reader
//dataReader = new System.IO.StreamReader(filestream, System.Text.Encoding.UTF8, true, 128);
dataReader = new System.IO.StreamReader(dataStream);
} catch (Exception) {
// message
MessageBox.Show("Could not create filestream to data file '" + filename + "' for reading");
info = null;
samples = null;
return(false);
}
// create a new bci2000 data object
info = new Data_BCI2000();
// retrieve the first line
info.firstLine = dataReader.ReadLine();
// retrieve HeaderLen
string fieldName = "HeaderLen=";
int fieldValueLength = 6;
int pos = info.firstLine.IndexOf(fieldName);
if (pos == -1 || info.firstLine.Length < pos + fieldName.Length + fieldValueLength)
{
MessageBox.Show("Could not retrieve " + fieldName + ", aborting");
info = null;
samples = null;
return(false);
}
bool result = Int32.TryParse(info.firstLine.Substring(pos + fieldName.Length, fieldValueLength), out info.headerLen);
if (!result)
{
MessageBox.Show("Could not retrieve " + fieldName + ", aborting");
info = null;
samples = null;
return(false);
}
// retrieve SourceCh
fieldName = "SourceCh=";
fieldValueLength = 2;
pos = info.firstLine.IndexOf(fieldName);
if (pos == -1 || info.firstLine.Length < pos + fieldName.Length + fieldValueLength)
{
MessageBox.Show("Could not retrieve " + fieldName + ", aborting");
info = null;
samples = null;
return(false);
}
result = Int32.TryParse(info.firstLine.Substring(pos + fieldName.Length, fieldValueLength), out info.sourceCh);
if (!result)
{
MessageBox.Show("Could not retrieve " + fieldName + ", aborting");
info = null;
samples = null;
return(false);
}
// retrieve StatevectorLen
fieldName = "StatevectorLen=";
//fieldValueLength = 3;
pos = info.firstLine.IndexOf(fieldName);
fieldValueLength = Math.Min(3, info.firstLine.Length - (pos + fieldName.Length)); // adjusted: fieldValueLength is variable: so it is either three, or in case the string is shorter, the remainder of the string: either 1 or 2
if (pos == -1 || info.firstLine.Length < pos + fieldName.Length + fieldValueLength)
{
MessageBox.Show("Could not retrieve " + fieldName + ", aborting");
info = null;
samples = null;
return(false);
}
result = Int32.TryParse(info.firstLine.Substring(pos + fieldName.Length, fieldValueLength), out info.stateVectorLen);
if (!result)
{
MessageBox.Show("Could not retrieve " + fieldName + ", aborting");
info = null;
samples = null;
return(false);
}
// retrieve entire header
char[] buffer = new char[info.headerLen];
dataStream.Position = 0;
dataReader.DiscardBufferedData();
dataReader.ReadBlock(buffer, 0, info.headerLen);
info.header = new string(buffer);
// retrieve the sample rate from the header
if (!getDoubleParameterFromHeader(info.header, "SamplingRate", out info.samplingRate))
{
MessageBox.Show("Could not retrieve sample rate from header, aborting");
info = null;
samples = null;
return(false);
}
// set the dataStream position to the start of the data (needed, readblock before messed it up)
dataStream.Position = info.headerLen;
// set
int mDataSize = 2; // each sample in BCI2000 is stored as an int16 (2 bytes)
// calculate the number of samples
info.numSamples = (int)(dataStream.Length - info.headerLen) / (mDataSize * info.sourceCh + info.stateVectorLen);
// init matrix for all samples values
samples = new double[info.numSamples][];
// retrieve the data
for (int i = 0; i < info.numSamples; i++)
{
// init the row of samples
samples[i] = new double[info.sourceCh];
// read the samples
byte[] channels = new byte[mDataSize * info.sourceCh];
dataStream.Read(channels, 0, mDataSize * info.sourceCh);
// convert each channel
for (int j = 0; j < info.sourceCh; j++)
{
samples[i][j] = BitConverter.ToInt16(channels, j * mDataSize);
}
// read the state vector data
byte[] stateVector = new byte[info.stateVectorLen];
dataStream.Read(stateVector, 0, info.stateVectorLen);
// TODO: interpret state vector
}
// close the datastream
if (dataStream != null)
{
dataStream.Close();
}
dataReader = null;
dataStream = null;
// return success
return(true);
}
private void btnConvertBCIToPalmtree_Click(object sender, EventArgs e)
{
// clear the output
txtOutput.Text = "";
// try to read the file
Data_BCI2000 info = new Data_BCI2000();
double[][] samples = null;
bool result = readBCI2000dat(txtInputFile.Text, out info, out samples);
// open file dialog to save dat file
SaveFileDialog dlgSaveDatFile = new SaveFileDialog();
dlgSaveDatFile.Filter = "Data files (*.dat)|*.dat|Data files (*.src)|*.src|All files (*.*)|*.*";
dlgSaveDatFile.RestoreDirectory = true; // restores current directory to the previously selected directory, potentially beneficial if other code relies on the currently set directory
// check if ok has been clicked on the dialog
if (dlgSaveDatFile.ShowDialog() != DialogResult.OK)
{
return;
}
FileStream dataStream = null;
try {
// create filestream: create file if it does not exists, allow to write, do not share with other processes and use buffer of 8192 bytes (roughly 1000 samples)
dataStream = new FileStream(dlgSaveDatFile.FileName, FileMode.Create, FileAccess.Write, FileShare.None, 8192);
} catch (Exception exc) {
MessageBox.Show("Unable to create data file at " + dlgSaveDatFile.FileName + " (" + exc.ToString() + ")");
return;
}
// generate stream names for the header (bci2000 does not have these)
string[] streamNames = new string[info.sourceCh];
for (int i = 0; i < streamNames.Length; i++)
{
streamNames[i] = "Ch" + (i + 1);
}
// create header
DataHeader header = new DataHeader();
header.version = 1;
header.code = "dat";
header.columnNames = streamNames;
header.numPlaybackStreams = streamNames.Length;
header.sampleRate = info.samplingRate;
// write header
if (dataStream != null)
{
DataWriter.writeBinaryHeader(dataStream, header);
}
// write data
uint dataSampleCounter = 0;
byte[] dataElapsedTimeBinary = BitConverter.GetBytes((1000.0 / header.sampleRate));
for (int i = 0; i < info.numSamples; i++)
{
// transform variables that will be stored in .dat to binary arrays (except for dataStreamValues array which is copied directly)
byte[] dataSampleCounterBinary = BitConverter.GetBytes(dataSampleCounter);
// transfer the values for output
double[] dataStreamValues = new double[info.sourceCh];
for (int j = 0; j < info.sourceCh; j++)
{
dataStreamValues[j] = samples[i][j];
}
// create new array to hold all bytes
int l1 = dataSampleCounterBinary.Length;
int l2 = dataElapsedTimeBinary.Length;
int l3 = dataStreamValues.Length * sizeof(double);
byte[] streamOut = new byte[l1 + l2 + l3];
// blockcopy all bytes to this array
Buffer.BlockCopy(dataSampleCounterBinary, 0, streamOut, 0, l1);
Buffer.BlockCopy(dataElapsedTimeBinary, 0, streamOut, l1, l2);
Buffer.BlockCopy(dataStreamValues, 0, streamOut, l1 + l2, l3);
// write data to file
if (dataStream != null)
{
dataStream.Write(streamOut, 0, streamOut.Length);
}
// increase sample counter
dataSampleCounter++;
}
// set output text
txtOutput.Text = "Done";
// clear
dataStream.Close();
dataStream = null;
}
