Fix FFT output over OSC not outputting all bins

Networking-Test-Kit/OSC/max-fft-parsing.js

@@ -0,0 +1,208 @@
+// OpenBCI FFT Data Parser for Max/MSP
+// PROVIDED AS-IS UNDER MIT LICENSE. NO WARRANTY OF ANY KIND. USE AT YOUR OWN RISK.
+// Usage:
+//   [udpreceive <port>] -> (route or oscbank) -> [js max-fft-parsing.js]
+//   Send list messages of the form: parseOSC <osc_address> <value>
+//   Example: parseOSC /openbci/fft/ch0/bin4 1.815383
+//
+// Provided JS functions (send as messages to the js object):
+//   parseOSC <address> <value>         // Update internal buffer for a single bin
+//   getChannel <channelIndex>          // Output all bins for channel on outlet 1
+//   getBandPower <ch> <startBin> <endBin> // Average power over bin range on outlet 2
+//   getEEGBands <channelIndex>         // Outputs delta, theta, alpha, beta, gamma on outlet 3
+//   getPeakFrequency <channelIndex>    // Outputs peak frequency (Hz) + amplitude on outlet 4
+//   outputMatrix                       // Outputs entire channel arrays on outlet 5
+//   setChannels <n>                    // Resize data structure (#channels)
+//   setBins <n>                        // Resize number of bins
+//   clear                              // Reset all stored values to 0
+//   testOutlets                        // Emits a test message from every outlet
+//
+// Outlets:
+//   0: bin_data <channel> <bin> <amplitude>
+//   1: channel_data <channel> <bin> <amplitude>
+//   2: band_power <channel> <startBin> <endBin> <avgPower>
+//   3: eeg_bands <channel> <delta> <theta> <alpha> <beta> <gamma>
+//   4: peak_freq <channel> <peakFreqHz> <amplitude>
+//   5: matrix <channel> <list_of_bin_values>
+//
+// NOTE: Declare outlets BEFORE doing work so Max creates them.
+var inlets = 1; // single inlet for all commands (var required for Max JS global)
+var outlets = 6; // six data/analysis outlets (var required for Max JS global)
+
+// Assist strings for UI clarity
+setoutletassist(0, 'bin_data: ch bin value');
+setoutletassist(1, 'channel_data: ch bin value');
+setoutletassist(2, 'band_power: ch startBin endBin avgPower');
+setoutletassist(3, 'eeg_bands: ch delta theta alpha beta gamma');
+setoutletassist(4, 'peak_freq: ch peakFreqHz amplitude');
+setoutletassist(5, 'matrix: ch list_of_bins');
+
+// Global variables to store FFT data
+var fftData = {};
+var numChannels = 8; // Adjust based on your OpenBCI setup
+var numBins = 125;
+var binSize = 2; // Hz per bin (assuming 250Hz sample rate)
+
+// Initialize data structure
+function init() {
+	for (var ch = 0; ch < numChannels; ch++) {
+		fftData[ch] = new Array(numBins);
+		for (var bin = 0; bin < numBins; bin++) {
+			fftData[ch][bin] = 0;
+		}
+	}
+	post(
+		'OpenBCI FFT Parser initialized for ' +
+			numChannels +
+			' channels, ' +
+			numBins +
+			' bins\n'
+	);
+}
+
+// Main function to parse incoming OSC messages
+function parseOSC() {
+	var oscAddress = arguments[0];
+	var value = arguments[1];
+
+	// Parse the OSC address pattern
+	// Expected format: /openbci/fft/ch{channel}/bin{bin}
+	// Match either /openbci/fft/chX/binY or /chX/binY (if prefix routed out earlier)
+	var addressMatch = oscAddress.match(/(?:\/openbci\/fft)?\/ch(\d+)\/bin(\d+)/);
+
+	if (addressMatch) {
+		var channel = parseInt(addressMatch[1], 10);
+		var bin = parseInt(addressMatch[2], 10);
+
+		// Store the FFT value
+		if (channel < numChannels && bin < numBins) {
+			fftData[channel][bin] = parseFloat(value);
+
+			// Output individual bin data
+			outlet(0, 'bin_data', channel, bin, value);
+		}
+	}
+}
+
+// Get FFT data for a specific channel
+function getChannel(channel) {
+	if (channel >= 0 && channel < numChannels && fftData[channel]) {
+		// Output all bins for this channel
+		for (var bin = 0; bin < numBins; bin++) {
+			outlet(1, channel, bin, fftData[channel][bin]);
+		}
+	}
+}
+
+// Get specific frequency band power
+function getBandPower(channel, startBin, endBin) {
+	if (channel >= 0 && channel < numChannels && fftData[channel]) {
+		var bandPower = 0;
+		var binCount = 0;
+
+		for (var bin = startBin; bin <= endBin && bin < numBins; bin++) {
+			bandPower += fftData[channel][bin];
+			binCount++;
+		}
+
+		if (binCount > 0) {
+			var avgPower = bandPower / binCount;
+			outlet(2, 'band_power', channel, startBin, endBin, avgPower);
+		}
+	}
+}
+
+// Get common EEG frequency bands
+function getEEGBands(channel) {
+	if (channel >= 0 && channel < numChannels && fftData[channel]) {
+		// Frequency bands (assuming 250Hz sample rate, 125 bins)
+		// Each bin = 2Hz, so bin N = N * 2 Hz
+
+		var delta = getBandAverage(channel, 0, 2); // 0-4 Hz
+		var theta = getBandAverage(channel, 2, 4); // 4-8 Hz
+		var alpha = getBandAverage(channel, 4, 6); // 8-12 Hz
+		var beta = getBandAverage(channel, 6, 15); // 12-30 Hz
+		var gamma = getBandAverage(channel, 15, 25); // 30-50 Hz
+
+		outlet(3, 'eeg_bands', channel, delta, theta, alpha, beta, gamma);
+	}
+}
+
+// Helper function to calculate average power in a bin range
+function getBandAverage(channel, startBin, endBin) {
+	var sum = 0;
+	var count = 0;
+
+	for (var bin = startBin; bin <= endBin && bin < numBins; bin++) {
+		sum += fftData[channel][bin];
+		count++;
+	}
+
+	return count > 0 ? sum / count : 0;
+}
+
+// Find peak frequency in a channel
+function getPeakFrequency(channel) {
+	if (channel >= 0 && channel < numChannels && fftData[channel]) {
+		var maxValue = 0;
+		var peakBin = 0;
+
+		for (var bin = 1; bin < numBins; bin++) {
+			// Skip DC component (bin 0)
+			if (fftData[channel][bin] > maxValue) {
+				maxValue = fftData[channel][bin];
+				peakBin = bin;
+			}
+		}
+
+		var peakFreq = peakBin * binSize;
+		outlet(4, 'peak_freq', channel, peakFreq, maxValue);
+	}
+}
+
+// Output all channel data as a matrix
+function outputMatrix() {
+	for (var ch = 0; ch < numChannels; ch++) {
+		if (fftData[ch]) {
+			var channelArray = [];
+			for (var bin = 0; bin < numBins; bin++) {
+				channelArray.push(fftData[ch][bin]);
+			}
+			outlet(5, 'matrix', ch, channelArray);
+		}
+	}
+}
+
+// Emit a test message from every outlet so user can confirm they exist
+function testOutlets() {
+	outlet(0, 'test', 'outlet0');
+	outlet(1, 'test', 'outlet1');
+	outlet(2, 'test', 'outlet2');
+	outlet(3, 'test', 'outlet3');
+	outlet(4, 'test', 'outlet4');
+	outlet(5, 'test', 'outlet5');
+	post('Emitted test messages on all 6 outlets\n');
+}
+
+// Set number of channels dynamically
+function setChannels(numCh) {
+	numChannels = parseInt(numCh);
+	init();
+	post('Set to ' + numChannels + ' channels\n');
+}
+
+// Set number of bins dynamically
+function setBins(numBin) {
+	numBins = parseInt(numBin);
+	init();
+	post('Set to ' + numBins + ' bins\n');
+}
+
+// Clear all data
+function clear() {
+	init();
+	post('FFT data cleared\n');
+}
+
+// Initialize on load
+init();