com.softsynth.math

Class AudioMath

java.lang.Object

com.softsynth.math.AudioMath

public class AudioMath
extends java.lang.Object

Miscellaneous math functions useful in Audio

Author:

(C) 1998 Phil Burk

Field Summary

Fields

Modifier and Type	Field and Description
static double	CONCERT_A_FREQUENCY
static int	CONCERT_A_PITCH

Constructor Summary

Constructors

Constructor and Description
AudioMath()

Method Summary

Modifier and Type	Method and Description
static double	amplitudeToDecibels(double amplitude) Convert amplitude to decibels.
static double	decibelsToAmplitude(double decibels) Convert decibels to amplitude.
static double	frequencyToPitch(double frequency) Calculate MIDI pitch based on frequency in Hertz.
static double	getConcertAFrequency()
static double	pitchToFrequency(double pitch) Calculate frequency in Hertz based on MIDI pitch.
static double	semitonesToFrequencyScaler(double semitones) Convert a delta value in semitones to a frequency multiplier.
static void	setConcertAFrequency(double concertAFrequency) This can be used to globally adjust the tuning in JSyn from Concert A at 440.0 Hz to a slightly different frequency.

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Field Detail

CONCERT_A_PITCH

public static final int CONCERT_A_PITCH

See Also:

Constant Field Values

CONCERT_A_FREQUENCY

public static final double CONCERT_A_FREQUENCY

See Also:

Constant Field Values

Constructor Detail

AudioMath

public AudioMath()

Method Detail

amplitudeToDecibels

public static double amplitudeToDecibels(double amplitude)

Convert amplitude to decibels. 1.0 is zero dB. 0.5 is -6.02 dB.

decibelsToAmplitude

public static double decibelsToAmplitude(double decibels)

Convert decibels to amplitude. Zero dB is 1.0 and -6.02 dB is 0.5.

frequencyToPitch

public static double frequencyToPitch(double frequency)

Calculate MIDI pitch based on frequency in Hertz. Middle C is 60.0.

pitchToFrequency

public static double pitchToFrequency(double pitch)

Calculate frequency in Hertz based on MIDI pitch. Middle C is 60.0. You can use fractional pitches so 60.5 would give you a pitch half way between C and C#.

setConcertAFrequency

public static void setConcertAFrequency(double concertAFrequency)

This can be used to globally adjust the tuning in JSyn from Concert A at 440.0 Hz to a slightly different frequency. Some orchestras use a higher frequency, eg. 441.0. This value will be used by pitchToFrequency() and frequencyToPitch().

Parameters:

concertAFrequency -

getConcertAFrequency

public static double getConcertAFrequency()

semitonesToFrequencyScaler

public static double semitonesToFrequencyScaler(double semitones)

Convert a delta value in semitones to a frequency multiplier.

Parameters:

semitones -

Returns:

scaler For example 2.0 for an input of 12.0 semitones.