OnsetsDS Vamp plugin

/*

        OnsetsDS - real time musical onset detection library.

    Copyright (c) 2007 Dan Stowell. All rights reserved.

    This program 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.

    This program 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 this program; if not, write to the Free Software

    Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA

*/

/** \file */

/**

 * \defgroup HelperFuncs        Convenience functions to apply OnsetsDS to a chunk of audio data, or to an audio file.

 * 

 * These functions are NOT required in order to use the core OnsetsDS functionality, but provide wrappers to

 * make it easy to apply OnsetsDS to time-domain data (audio chunks, or audio files) without having to write the

 * FFT processing yourself.

 */

 //@{ 

#ifndef _OnsetsDSHelpers_

#define _OnsetsDSHelpers_

#ifdef __cplusplus

extern "C" {

#endif

#include <fftw3.h>

#include "../onsetsds.h"

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

/**

When using onsetsds_process_audiofile(), this specifies that your callback function should

take an #OnsetsDS and a double as arguments, and return void. The double will be a time

offset, from the beginning of the recording, at which the detected onset occurred.

*/

typedef void (*ODSFileCallback)(OnsetsDS*, double);

/**

Holds all the state data required by onsetsds_process_audiodata(), including a pointer to an #OnsetsDS

as well as the time-domain/freq-domain buffers.

Also remembers the FFT frame size, hop size.

*/

typedef struct OnsetsDSAudioBuf{

        OnsetsDS* ods;

        size_t buflen;

        size_t hopsize;

        size_t writepos;

        float *data;         // size will be buflen

        float *window;       // size will be buflen

        float *windoweddata; // size will be buflen

        float *fftbuf; // size will be buflen

        fftwf_plan fftplan;

        // Whole-file-only things (i.e. unused when you're pushing audio blocks yourself):

        long sampsElapsed;

        double samplerate;

        ODSFileCallback filecallback;

} OnsetsDSAudioBuf;

/**

When using onsetsds_process_audiodata(), this specifies that your callback function should

take an #OnsetsDSAudioBuf and a size_t as arguments, and return void. The size_t will be a sample

offset at which the detected onset occurred, within the audio frame that was just passed in. (More than 

one onset per audio frame is possible, depending on how much data you're passing in at a time.)

*/

typedef void (*ODSDataCallback)(OnsetsDSAudioBuf*, size_t);

/**

This data structure stores statistics derived from using onsetsds_evaluate_audiofile(), describing how well

the onset detector matched the "ground truth" annotations.

*/

typedef struct OnsetsDSEvalData{

        long numGT; ///< How many ground truth annotations were provided

        long numAnnot; ///< How many onsets it found

        long numTP; ///< How many correct detections occurred

        long numFP; ///< How many false positives occurred

        long numFN; ///< How many false negatives occurred

        float precision; ///< 0 to 1: a measure of resistance against false positives

        float recall; ///< 0 to 1: a measure of resistance against false negatives

        float f; ///< 0 to 1: the "F-measure", a combination of the precision and recall statistics

        float devimean; ///< Mean of each onset's deviation from the annotated onset, a rough indicator of reacting "too quickly"/"too slowly"

        float deviabsmean; ///< Absolute mean of each onset's deviation from the annotated onset, a rough indicator of temporal accuracy

        float devisd; ///< Standard deviation re devimean, useful when combining stats

        float deviabssd; ///< Standard deviation re deviabsmean, useful when combining stats

} OnsetsDSEvalData;

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

/**

Set up the data structures for use by onsetsds_process_audiodata().

@param odsbuf        Will be set up nicely by this function.

@param ods                Must have been initialised properly before calling this function.

@param hopsize        Hop size in samples (256 is recommended)

*/

void onsetsds_init_audiodata(OnsetsDSAudioBuf* odsbuf, OnsetsDS* ods, size_t hopsize);

/**

Correctly deallocate and destroy the #OnsetsDSAudioBuf. Use this after onsetsds_process_audiofile(), or after you've finished

running a series of onsetsds_process_audiodata() calls.

@param odsbuf        

*/

void onsetsds_destroy_audiodata(OnsetsDSAudioBuf* odsbuf);

/**

Process a new chunk of audio data. 

@param odsbuf        Must have been initialised properly before calling this function, using onsetsds_init_audiodata()

@param data                The *new* chunk of mono, time-domain audio data. Internal buffers will handle frame overlap etc. The size 

                        of the input data does *not* need to have a relation to the frame size or hop size.

@param datalen        Size of the data buffer.

@param callback        Name of your callback function, which will be called whenever an onset is detected. 

                        It will be passed the #OnsetsDSAudioBuf object and (more importantly) the sample offset at which the onset was detected 

                        (i.e. a value between 0 and datalen).

*/

void onsetsds_process_audiodata(OnsetsDSAudioBuf* odsbuf, float* data, size_t datalen, 

                        ODSDataCallback callback);

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

/**

Process an entire file of audio data. Returns 0 if successful (may fail if it can't find/open the audio file, for example).

@param odsbuf                Must have been initialised properly before calling this function, using onsetsds_init_audiodata()

@param infilename        The file to be loaded.

@param callback                Name of your callback function, which will be called whenever an onset is detected. 

                        It will be passed the #OnsetsDS object and (more importantly) the time offset in seconds at which the onset was detected 

                        (a double-precision-floating-point value between 0 and the duration of the audio file).

*/

int onsetsds_process_audiofile(OnsetsDSAudioBuf* odsbuf, const char *infilename,

                        ODSFileCallback callback);

/**

Process an entire file of audio data and compare the onset detector's output against a single "ground truth" annotation of where the 

onsets really are. 

@param odsbuf                Must have been initialised properly before calling this function, using onsetsds_init_audiodata()

@param infilename        The file to be loaded.

@param gtfilename        The file containing a text list of ground-truth annotations, one number per line, each being an onset's

                                                position in seconds from the beginning of the file. The numbers must be in ascending order.

                                                This format can be easily exported from programs 

                                                such as <a href="http://www.sonicvisualiser.org/">Sonic Visualiser</a>.

@param results                Pointer to the #OnsetsDSEvalData where the results should be written.

*/

int onsetsds_evaluate_audiofile(OnsetsDSAudioBuf* odsbuf, const char *infilename, const char *gtfilename, OnsetsDSEvalData* results);

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

#ifdef __cplusplus

}

#endif

#endif

//@}