OnsetsDS

2011-02  Dan Stowell

    * Add matlab/octave wrapper

#!/bin/bash

# Script to make a download bundle of the OnsetsDS code

# Dan Stowell, June 2008

version=`date "+%Y-%m-%d"`

# build the documentation

cd doc

doxygen

cd ..

rm -rf OnsetsDS

svn export . OnsetsDS

cp -R doc/html OnsetsDS/doc/html

zip -r "OnsetsDS-$version" OnsetsDS

tar -czvf "OnsetsDS-$version.tgz" OnsetsDS

<small>Copyright (c) 2007 Dan Stowell (Published under the GNU Public License v2 or later). 

(Added Feb 2011: matlab/octave wrapper, an offline function onsetsds() which can

be applied to a matrix of fft data)

	<li><a href="https://sourceforge.net/projects/onsetsds/files/onsetsds/OnsetsDS-source/">Download the sourcecode bundle</a></li>

//-/////// (1) INITIALISATION: ///////-//

// Allocate contiguous memory using malloc or whatever is reasonable.

float* odsdata = (float*) malloc( onsetsds_memneeded(odftype, 512, 11) );

// Now initialise the OnsetsDS struct and its associated memory

onsetsds_init(&ods, odsdata, ODS_FFT_FFTW3_HC, odftype, 512, 11, 44100.f);

//-/////// (2) EXECUTION:      ///////-//

   // Grab your 512- or 1024-point, 50%-overlap, nicely-windowed FFT data, into "fftdata"

   onset = onsetsds_process(&ods, fftdata);

//-/////// (3) TIDYING UP:     ///////-//

mex                    -I../src  onsetsds.c ../src/onsetsds.c

/**

    This file is part of "onsetsds".

    (c) 2011 Dan Stowell and Queen Mary University of London

    All rights reserved.

    onsetsds 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.

    onsetsds 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 kdpee.  If not, see <http://www.gnu.org/licenses/>.

*/

#include "math.h"

#include "mex.h"

#include "onsetsds.h"

////////////////////////////////////////////////////////////////////////

// MATLAB ENTRY FUNCTION:

void mexFunction(int nlhs, mxArray *plhs[], int nrhs, const mxArray *prhs[])

{

	// implementation of: onsetsds(fftdata, odftype, medspan, srate)

	// Get the star of the show, the fft data

	const mxArray *fftdata;	

	fftdata = prhs[0];

	if(!mxIsComplex(fftdata)){

    	mexErrMsgTxt("onsetsds expects a matrix of complex data (e.g. from fft()).\n");

	}

	const size_t fftframesize = mxGetM(fftdata);

	const size_t numframes    = mxGetN(fftdata);

	const double* real = mxGetPr(fftdata);

	const double* imag = mxGetPi(fftdata);

	// optional args

	int odftype = ODS_ODF_RCOMPLEX;

	if(nrhs>1){

		odftype = mxGetScalar(prhs[1]);

		if((odftype < 0) || (newodftype > 6))

    		mexErrMsgTxt("onsetsds: unrecognised ODF type.\n");

	}

	const unsigned int medspan

	                  = (nrhs<3) ? 11 : (unsigned int) mxGetScalar(prhs[2]);

	const float srate = (nrhs<4) ? 44100.f : (float) mxGetScalar(prhs[3]);

	// set up the ods

	OnsetsDS ods;

	float* odsdata = (float*) malloc( onsetsds_memneeded(odftype, fftframesize, medspan) );

	onsetsds_init(&ods, odsdata, ODS_FFT_SC3_COMPLEX, odftype, fftframesize, medspan, srate);

	// This is where we'll repack an individual frame

	float* packeddata = malloc(fftframesize * sizeof(float));

	// set up the output array, size numframes

	double *results = (double*) mxCalloc(numframes, sizeof(double));

	if(!results){

    	mexErrMsgTxt("onsetsds error, could not create results array (out of memory?).\n");

	}

	////////////////////////////////////////////////////////////////////////////

	// iterate the frames, converting to expected format and onset-detecting

	size_t i;

	for(i=0; i<numframes; ++i){

		// copy the data into an array in ODS_FFT_SC3_COMPLEX format.

		// note that here we're discarding stuff above nyquist, since assuming real-valued input.

		size_t frameoffset = fftframesize * i;

		packeddata[0] = (float) real[frameoffset];

		packeddata[1] = (float) real[frameoffset + fftframesize / 2];

		size_t j;

		for(j=1; j< fftframesize/2; ++j){

			packeddata[j+j]   = (float) real[frameoffset + j];

			packeddata[j+j+1] = (float) imag[frameoffset + j];

		}

		bool onset = onsetsds_process(&ods, packeddata);

		results[i] = (onset ? 1.0 : 0.0);

	}	

	// Copy the results from double-array into matlab format

	mxArray *resultsM = mxCreateDoubleMatrix(1,numframes,mxREAL);

	memcpy(mxGetPr(resultsM), results, numframes * sizeof(double));

	plhs[0] = resultsM;

	// destroy the ods correctly, and any matlabby things that need to go too.

	free(ods.data);

	free(packeddata);

	mxFree(results);

}

function onsets = onsetsds(fftdata, odftype, medspan, srate)

% function onsets = onsetsds(fftdata)

% function onsets = onsetsds(fftdata, odftype)

% function onsets = onsetsds(fftdata, odftype, medspan)

% function onsets = onsetsds(fftdata, odftype, medspan, srate)

%

% Musical onset detector using adaptive whitening 

%     -- see http://onsetsds.sourceforge.net/

%

%  "fftdata": a matrix of FFT frames (1 per column) derived from an audio 

%             file. The common case (used for testing the code) is 44.1 kHz 

%             audio with 50% overlap and Hann windowing.

%

%  "odftype": integer specifying onset detection function to use:

%              0 'power', 

%              1 'magsum', 

%              2 'complex',

%              3 'rcomplex',  <-- default

%              4 'phase', 

%              5 'wphase', 

%              6 'mkl'.

%  "medspan": length of median-filter in frames, default is 11.

%  "srate": sampling rate of audio, default is 44100.

%

% For more info see D. Stowell and M. D. Plumbley, 

%         "Adaptive whitening for improved real-time audio onset detection", 

%         Proceedings of the International Computer Music Conference (ICMC'07), 

%         Copenhagen, Denmark, August 2007.

%

%   onsetsds 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 2 of the License, or

%   (at your option) any later version.

static inline float onsetsds_phase_rewrap(float phase){

	ODS_FFT_SC3_COMPLEX,	  ///< SuperCollider, cartesian co-ords ("SCComplexBuf") [dc, nyq, real[1], imag[1], real[2], imag[2]...] - NB it's more efficient to provide polar data from SC

	ODS_FFT_SC3_POLAR,	  ///< SuperCollider, polar co-ords ("SCPolarBuf") [dc, nyq, mag[1], phase[1], mag[2], phase[2]...]

	ODS_FFT_FFTW3_HC, ///< FFTW <a href="http://www.fftw.org/fftw3_doc/The-Halfcomplex_002dformat-DFT.html">"halfcomplex"</a> format - [dc, real[1], real[2] ... nyq, imag[nyq-1] ... imag[1]]

#include "onsetsds.h"