/*
* Copyright 2013-2014 TECO - Karlsruhe Institute of Technology.
*
* This file is part of TACET.
*
* TACET is free software: you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation, either version 3 of the License, or
* (at your option) any later version.
*
* TACET is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with TACET. If not, see <http://www.gnu.org/licenses/>.
*/
package squirrel.model.video;
import java.util.LinkedList;
/**
* The Class SyncData. Calculates the linear regression of each video track to
* the sensor data track
*/
public class SyncData {
private LinkedList<SyncPoint> syncPoints;
private int numberOfTracks;
private int numberOfPoints;
private float[] videoSpeed;
private long[] startTime;
private boolean setSynchronisation = false;
/**
* Instantiates a new syncData.
*
* @param nOT the number of tracks
*/
public SyncData(int nOT) {
this.startTime = new long[nOT - 1];
this.videoSpeed = new float[nOT - 1];
for (int i = 0; i < nOT - 1; i++) {
this.startTime[i] = 0;
this.videoSpeed[i] = 1;
}
this.syncPoints = new LinkedList<SyncPoint>();
this.numberOfTracks = nOT;
this.numberOfPoints = 0;
}
/**
* Gets the number of SyncPoints added to SyncData.
*
* @return the number of SyncPoints
*/
public int geNumberOfPonts() {
return numberOfPoints;
}
/**
* Gets the start times of the synchronized video tracks.
*
* @return the start times
*/
public long[] getStartTimes() {
return startTime;
}
/**
* Gets the video speed of the synchronized video tracks.
*
* @return the video speed
*/
public float[] getVideoSpeed() {
return videoSpeed;
}
/**
* Sets the indicator of ending the synchronization true.
*/
public void setSynchronisation() {
this.setSynchronisation = true;
}
/**
* Sync is set.
*
* @return true, if the synchronisation has ended
*/
public boolean syncIsSet() {
return setSynchronisation;
}
/**
* Adds the sync point.
*
* @param sp the syncPoint
*/
public void addSyncPoint(SyncPoint sp) {
if (sp.getSyncTimeStamps().length == numberOfTracks) {
syncPoints.add(sp);
numberOfPoints++;
}
}
/**
* Removes the sync points with the selected indexes.
*
* @param selIdxs the selected indexes
*/
public void removeSynPoints(int[] selIdxs) {
for (int i = selIdxs.length - 1; i >= 0; i--) {
syncPoints.remove(selIdxs[i]);
numberOfPoints--;
}
}
/**
* Synchronizes the tracks.
*/
public void synchronize() {
if (numberOfPoints == 0) {
startTime = new long[numberOfTracks - 1];
videoSpeed = new float[numberOfTracks - 1];
for (int i = 0; i < numberOfTracks - 1; i++) {
startTime[i] = 0;
videoSpeed[i] = 1;
}
} else if (numberOfPoints == 1) {
startTime = new long[numberOfTracks - 1];
videoSpeed = new float[numberOfTracks - 1];
SyncPoint sp = syncPoints.getFirst();
for (int i = 0; i < numberOfTracks - 1; i++) {
startTime[i] = sp.getValue(0) - sp.getValue(i + 1);
videoSpeed[i] = 1;
}
} else {
double[] avg = calculateAvg();
double[] deviation = calculateDeviation(avg);
double[] correlation = calculateCorrelation(avg, deviation);
calculateVideoSpeed(correlation, deviation);
calculateStartTime(avg);
}
}
private double[] calculateAvg() {
double[] avg = new double[numberOfTracks];
double sum = 0;
for (int i = 0; i < numberOfTracks; i++) {
int counter = 0;
for (SyncPoint sp : syncPoints) {
if (sp.getValue(i) >= 0) {
sum = sum + sp.getValue(i);
counter++;
}
}
if (counter > 0) {
avg[i] = sum / counter;
} else {
avg[i] = 1;
}
sum = 0;
}
return avg;
}
private double[] calculateDeviation(double[] avg) {
double[] deviation = new double[numberOfTracks];
double sum = 0;
for (int i = 0; i < numberOfTracks; i++) {
int counter = numberOfPoints;
for (SyncPoint sp : syncPoints) {
if (sp.getValue(i) >= 0) {
sum = sum + ((sp.getValue(i) - avg[i]) * (sp.getValue(i) - avg[i]));
} else {
counter--;
}
}
if (counter > 1) {
deviation[i] = Math.sqrt(sum / (counter - 1));
} else {
deviation[i] = 1;
}
sum = 0;
}
return deviation;
}
private double[] calculateCorrelation(double[] avg, double[] deviation) {
double[] correlation = new double[numberOfTracks - 1];
double sum = 0;
for (int i = 1; i < numberOfTracks; i++) {
int counter = numberOfPoints;
for (SyncPoint sp : syncPoints) {
if (sp.getValue(i) >= 0) {
sum = sum + ((sp.getValue(i) - avg[i]) * (sp.getValue(0) - avg[0]));
} else {
counter--;
}
}
if (counter > 1) {
correlation[i - 1] = (sum / (counter - 1)) / (deviation[i] * deviation[0]);
} else {
correlation[i - 1] = 1;
}
sum = 0;
}
return correlation;
}
private void calculateVideoSpeed(double[] correlation, double[] deviation) {
videoSpeed = new float[numberOfTracks - 1];
for (int i = 0; i < numberOfTracks - 1; i++) {
videoSpeed[i] = (float) (correlation[i] * deviation[i + 1] / deviation[0]);
}
}
private void calculateStartTime(double[] avg) {
startTime = new long[numberOfTracks - 1];
for (int i = 0; i < numberOfTracks - 1; i++) {
startTime[i] = Math.round(avg[0] - (avg[i + 1] / videoSpeed[i]));
}
}
}