mirror of
https://github.com/WinampDesktop/winamp.git
synced 2024-12-12 16:41:06 -05:00
91 lines
3.8 KiB
C
91 lines
3.8 KiB
C
|
////////////////////////////////////////////////////////////////////////////////
|
||
|
///
|
||
|
/// The routine detects highest value on an array of values and calculates the
|
||
|
/// precise peak location as a mass-center of the 'hump' around the peak value.
|
||
|
///
|
||
|
/// 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 _PeakFinder_H_
|
||
|
#define _PeakFinder_H_
|
||
|
|
||
|
namespace soundtouch
|
||
|
{
|
||
|
|
||
|
class PeakFinder
|
||
|
{
|
||
|
protected:
|
||
|
/// Min, max allowed peak positions within the data vector
|
||
|
int minPos, maxPos;
|
||
|
|
||
|
/// Calculates the mass center between given vector items.
|
||
|
double calcMassCenter(const float *data, ///< Data vector.
|
||
|
int firstPos, ///< Index of first vector item belonging to the peak.
|
||
|
int lastPos ///< Index of last vector item belonging to the peak.
|
||
|
) const;
|
||
|
|
||
|
/// Finds the data vector index where the monotoniously decreasing signal crosses the
|
||
|
/// given level.
|
||
|
int findCrossingLevel(const float *data, ///< Data vector.
|
||
|
float level, ///< Goal crossing level.
|
||
|
int peakpos, ///< Peak position index within the data vector.
|
||
|
int direction /// Direction where to proceed from the peak: 1 = right, -1 = left.
|
||
|
) const;
|
||
|
|
||
|
// Finds real 'top' of a peak hump from neighnourhood of the given 'peakpos'.
|
||
|
int findTop(const float *data, int peakpos) const;
|
||
|
|
||
|
|
||
|
/// Finds the 'ground' level, i.e. smallest level between two neighbouring peaks, to right-
|
||
|
/// or left-hand side of the given peak position.
|
||
|
int findGround(const float *data, /// Data vector.
|
||
|
int peakpos, /// Peak position index within the data vector.
|
||
|
int direction /// Direction where to proceed from the peak: 1 = right, -1 = left.
|
||
|
) const;
|
||
|
|
||
|
/// get exact center of peak near given position by calculating local mass of center
|
||
|
double getPeakCenter(const float *data, int peakpos) const;
|
||
|
|
||
|
public:
|
||
|
/// Constructor.
|
||
|
PeakFinder();
|
||
|
|
||
|
/// Detect exact peak position of the data vector by finding the largest peak 'hump'
|
||
|
/// and calculating the mass-center location of the peak hump.
|
||
|
///
|
||
|
/// \return The location of the largest base harmonic peak hump.
|
||
|
double detectPeak(const float *data, /// Data vector to be analyzed. The data vector has
|
||
|
/// to be at least 'maxPos' items long.
|
||
|
int minPos, ///< Min allowed peak location within the vector data.
|
||
|
int maxPos ///< Max allowed peak location within the vector data.
|
||
|
);
|
||
|
};
|
||
|
|
||
|
}
|
||
|
|
||
|
#endif // _PeakFinder_H_
|