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Diffstat (limited to 'lib/soundtouch/BPMDetect.h')
| -rw-r--r-- | lib/soundtouch/BPMDetect.h | 205 |
1 files changed, 0 insertions, 205 deletions
diff --git a/lib/soundtouch/BPMDetect.h b/lib/soundtouch/BPMDetect.h deleted file mode 100644 index 8ece78448d..0000000000 --- a/lib/soundtouch/BPMDetect.h +++ /dev/null @@ -1,205 +0,0 @@ -////////////////////////////////////////////////////////////////////////////////
-///
-/// Beats-per-minute (BPM) detection routine.
-///
-/// The beat detection algorithm works as follows:
-/// - Use function 'inputSamples' to input a chunks of samples to the class for
-/// analysis. It's a good idea to enter a large sound file or stream in smallish
-/// chunks of around few kilosamples in order not to extinguish too much RAM memory.
-/// - Input sound data is decimated to approx 500 Hz to reduce calculation burden,
-/// which is basically ok as low (bass) frequencies mostly determine the beat rate.
-/// Simple averaging is used for anti-alias filtering because the resulting signal
-/// quality isn't of that high importance.
-/// - Decimated sound data is enveloped, i.e. the amplitude shape is detected by
-/// taking absolute value that's smoothed by sliding average. Signal levels that
-/// are below a couple of times the general RMS amplitude level are cut away to
-/// leave only notable peaks there.
-/// - Repeating sound patterns (e.g. beats) are detected by calculating short-term
-/// autocorrelation function of the enveloped signal.
-/// - After whole sound data file has been analyzed as above, the bpm level is
-/// detected by function 'getBpm' that finds the highest peak of the autocorrelation
-/// function, calculates it's precise location and converts this reading to bpm's.
-///
-/// Author : Copyright (c) Olli Parviainen
-/// Author e-mail : oparviai 'at' iki.fi
-/// SoundTouch WWW: http://www.surina.net/soundtouch
-///
-////////////////////////////////////////////////////////////////////////////////
-//
-// License :
-//
-// SoundTouch audio processing library
-// Copyright (c) Olli Parviainen
-//
-// This library is free software; you can redistribute it and/or
-// modify it under the terms of the GNU Lesser General Public
-// License as published by the Free Software Foundation; either
-// version 2.1 of the License, or (at your option) any later version.
-//
-// This library 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
-// Lesser General Public License for more details.
-//
-// You should have received a copy of the GNU Lesser General Public
-// License along with this library; if not, write to the Free Software
-// Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
-//
-////////////////////////////////////////////////////////////////////////////////
-
-#ifndef _BPMDetect_H_
-#define _BPMDetect_H_
-
-#include <vector>
-#include "STTypes.h"
-#include "FIFOSampleBuffer.h"
-
-namespace soundtouch
-{
-
- /// Minimum allowed BPM rate. Used to restrict accepted result above a reasonable limit.
- #define MIN_BPM 45
-
- /// Maximum allowed BPM rate range. Used for calculating algorithm parametrs
- #define MAX_BPM_RANGE 200
-
- /// Maximum allowed BPM rate range. Used to restrict accepted result below a reasonable limit.
- #define MAX_BPM_VALID 190
-
-////////////////////////////////////////////////////////////////////////////////
-
- typedef struct
- {
- float pos;
- float strength;
- } BEAT;
-
-
- class IIR2_filter
- {
- double coeffs[5];
- double prev[5];
-
- public:
- IIR2_filter(const double *lpf_coeffs);
- float update(float x);
- };
-
-
- /// Class for calculating BPM rate for audio data.
- class BPMDetect
- {
- protected:
- /// Auto-correlation accumulator bins.
- float *xcorr;
-
- /// Sample average counter.
- int decimateCount;
-
- /// Sample average accumulator for FIFO-like decimation.
- soundtouch::LONG_SAMPLETYPE decimateSum;
-
- /// Decimate sound by this coefficient to reach approx. 500 Hz.
- int decimateBy;
-
- /// Auto-correlation window length
- int windowLen;
-
- /// Number of channels (1 = mono, 2 = stereo)
- int channels;
-
- /// sample rate
- int sampleRate;
-
- /// Beginning of auto-correlation window: Autocorrelation isn't being updated for
- /// the first these many correlation bins.
- int windowStart;
-
- /// window functions for data preconditioning
- float *hamw;
- float *hamw2;
-
- // beat detection variables
- int pos;
- int peakPos;
- int beatcorr_ringbuffpos;
- int init_scaler;
- float peakVal;
- float *beatcorr_ringbuff;
-
- /// FIFO-buffer for decimated processing samples.
- soundtouch::FIFOSampleBuffer *buffer;
-
- /// Collection of detected beat positions
- //BeatCollection beats;
- std::vector<BEAT> beats;
-
- // 2nd order low-pass-filter
- IIR2_filter beat_lpf;
-
- /// Updates auto-correlation function for given number of decimated samples that
- /// are read from the internal 'buffer' pipe (samples aren't removed from the pipe
- /// though).
- void updateXCorr(int process_samples /// How many samples are processed.
- );
-
- /// Decimates samples to approx. 500 Hz.
- ///
- /// \return Number of output samples.
- int decimate(soundtouch::SAMPLETYPE *dest, ///< Destination buffer
- const soundtouch::SAMPLETYPE *src, ///< Source sample buffer
- int numsamples ///< Number of source samples.
- );
-
- /// Calculates amplitude envelope for the buffer of samples.
- /// Result is output to 'samples'.
- void calcEnvelope(soundtouch::SAMPLETYPE *samples, ///< Pointer to input/output data buffer
- int numsamples ///< Number of samples in buffer
- );
-
- /// remove constant bias from xcorr data
- void removeBias();
-
- // Detect individual beat positions
- void updateBeatPos(int process_samples);
-
-
- public:
- /// Constructor.
- BPMDetect(int numChannels, ///< Number of channels in sample data.
- int sampleRate ///< Sample rate in Hz.
- );
-
- /// Destructor.
- virtual ~BPMDetect();
-
- /// Inputs a block of samples for analyzing: Envelopes the samples and then
- /// updates the autocorrelation estimation. When whole song data has been input
- /// in smaller blocks using this function, read the resulting bpm with 'getBpm'
- /// function.
- ///
- /// Notice that data in 'samples' array can be disrupted in processing.
- void inputSamples(const soundtouch::SAMPLETYPE *samples, ///< Pointer to input/working data buffer
- int numSamples ///< Number of samples in buffer
- );
-
- /// Analyzes the results and returns the BPM rate. Use this function to read result
- /// after whole song data has been input to the class by consecutive calls of
- /// 'inputSamples' function.
- ///
- /// \return Beats-per-minute rate, or zero if detection failed.
- float getBpm();
-
- /// Get beat position arrays. Note: The array includes also really low beat detection values
- /// in absence of clear strong beats. Consumer may wish to filter low values away.
- /// - "pos" receive array of beat positions
- /// - "values" receive array of beat detection strengths
- /// - max_num indicates max.size of "pos" and "values" array.
- ///
- /// You can query a suitable array sized by calling this with NULL in "pos" & "values".
- ///
- /// \return number of beats in the arrays.
- int getBeats(float *pos, float *strength, int max_num);
- };
-}
-#endif // _BPMDetect_H_
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