/* * Copyright 2006 Columbia University. * * This file is part of MEAPsoft. * * MEAPsoft is free software; you can redistribute it and/or modify * it under the terms of the GNU General Public License version 2 as * published by the Free Software Foundation. * * MEAPsoft 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 MEAPsoft; if not, write to the Free Software * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA * 02110-1301 USA * * See the file "COPYING" for the text of the license. */ package com.meapsoft; import java.util.Arrays; import com.meapsoft.featextractors.*; /* * Onset detector based on Dan Ellis' beattrack.m. * * Get an envelope that indicates the onsets. Here, we take a dB mel * spectrogram, sum it across frequency, then take first order * difference (and maybe smooth the result). * * @author Dan Ellis (dpwe@ee.columbia.edu) * @author Ron Weiss (ronw@ee.columbia.edu) */ public class DpweOnsetDetector extends OnsetDetector { // Onset detection function computed from the STFT protected double[] onsetFunction; // number of frames in onsetFunction private long numFrames; // silence threshold in dB protected double silenceThresh = -40; // gain applied to the median filter threshold in checkOnsets private double threshMult = 1; private AvgMelSpec melSpec; private double[] lastMelFrame = null; private double smtime = 0.10; static final int sr = 32000; static final int swin = 1024; static final int nmel = 40; static final double sgsrate = sr/(swin/2); // dpwe debug 2006-12-11 //static final int nDebugFrames = 1500; //private double[][] melFrames = new double[nDebugFrames][nmel]; //private int nMelFrames = 0; //private double[] boost; //private double[][] specgram; public DpweOnsetDetector(STFT stft, long numFrames, double thresh) { super(stft, 0, 0); threshMult = thresh; onsetFunction = new double[(int)numFrames]; this.numFrames = numFrames; melSpec = new AvgMelSpec(swin/2+1, sr, nmel); // low frequency boost for bass drum //double[] freqs = DSP.times(DSP.range(0,swin/2), sr/swin); // double[] lfboost = DSP.times(DSP.log10(DSP.max(DSP.plus(DSP.rdivide(DSP.minus(200, freqs), 200.0), 1), 1)), 10.0); // // high frequency boost for noisy drums // //double[] hfboost = DSP.times(DSP.log10(DSP.max(DSP.plus(DSP.rdivide(DSP.minus(freqs, 6000), 6000), 1), 1)), 10.0); // double[] hfboost = new double[lfboost.length]; //for(int x = 0; x < hfboost.length; x++) //{ // if(freqs[x] < 6000) // hfboost[x] = 0; // else // hfboost[x] = 3; //} //boost = DSP.plus(lfboost, hfboost); //DSP.imagesc(boost); //specgram = new double[(int)numFrames][stft.getColumns()]; } public DpweOnsetDetector(STFT stft, long numFrames, double thresh, double smt) { this(stft, numFrames, thresh); smtime = smt; } /** * Computes the onset detection function in real time as the STFT * gets new frames. Once the final frame is reached, look for * onsets in the detection function. */ public void newFrame(STFT stft, long newestFrame) { if(newestFrame <= numFrames && newestFrame != -1) { // apply frequency weights //double[] D = stft.getFrame(newestFrame); //stft.setFrame(newestFrame, DSP.plus(D, boost)); //if(newestFrame < specgram.length) // specgram[(int)newestFrame] = stft.getFrame(newestFrame); double[] melFrame = melSpec.features(stft, newestFrame, 1); // threshold: melFrame = DSP.max(melFrame, silenceThresh); // dpwe debug 2006-12-11 // if (nMelFrames < nDebugFrames) { // for (int j = 0; j < nmel; ++j) { // melFrames[nMelFrames][j] = melFrame[j]; // } // ++nMelFrames; // if (nMelFrames == nDebugFrames) { // DSP.imagesc(melFrames, "melFrames"); // } // } // is this the first frame we've seen? if(lastMelFrame == null) { lastMelFrame = melFrame; return; } long currFrame = newestFrame-1; onsetFunction[(int)currFrame] = DSP.mean(DSP.max(DSP.minus(melFrame, lastMelFrame), 0)); lastMelFrame = melFrame; } else { // if this is the last frame in stft, do some smoothing and // find local maxes. checkOnsets(); } } protected void checkOnsets() { //DSP.imagesc(specgram, "specgram"); //DSP.imagesc(onsetFunction, "onset function"); //DSP.wavwrite(DSP.rdivide(onsetFunction, DSP.max(onsetFunction)), (int)sgsrate, "onsetFunction.wav"); // smooth like crazy int winLen = (int)(smtime*sgsrate); // make it odd winLen = (int)Math.round((winLen-1)/2)*2 + 1; double[] smwin = DSP.hanning(winLen); smwin = DSP.times(smwin, 1/DSP.sum(smwin)); onsetFunction = DSP.conv(smwin, onsetFunction); onsetFunction = DSP.slice(onsetFunction, (int)(winLen-1)/2, (int)(winLen-1)/2+(int)numFrames-1); // remove DC double[] b = {1, -1}; double[] a = {1, -0.99}; onsetFunction = DSP.filter(b, a, onsetFunction); onsetFunction = DSP.max(onsetFunction, 0); // normalize //onsetFunction = DSP.times(onsetFunction, 1/DSP.max(onsetFunction)); // find local maxima in onsetFunction //double[] threshFunc = new double[onsetFunction.length]; double dcThresh = 0.005; int nwin = 50; for(int fr = 1; fr < onsetFunction.length-1; fr++) { // threshold using a median filter over 50 point window: double thresh = dcThresh + threshMult * DSP.median(DSP.slice(onsetFunction, fr > nwin/2 ? fr-nwin/2 : 0, fr > onsetFunction.length - nwin/2 ? onsetFunction.length : fr+nwin/2-1)); //threshFunc[fr] = thresh; if(onsetFunction[fr] > thresh && onsetFunction[fr] > onsetFunction[fr-1] && onsetFunction[fr] > onsetFunction[fr+1]) notifyListeners(fr, 0); } //System.out.println(threshMult); //DSP.imagesc(onsetFunction, "smoothed onsetFunc"); //DSP.imagesc(threshFunc, "thresh"); //int len = (int)Math.min(20000, onsetFunction.length); //double[][] d = new double[2][len]; //d[1] = DSP.slice(onsetFunction, 0, len); //d[0] = DSP.slice(threshFunc, 0, len); //DSP.imagesc(DSP.transpose(d), "onset function and threshold"); //DSP.wavwrite(onsetFunction, (int)sgsrate, "smoothedOnsetFunction.wav"); //DSP.wavwrite(threshFunc, (int)sgsrate, "threshFunction.wav"); } }