com.tagtraum.jipes.audio

Class AbstractAudioSpectrum

java.lang.Object

com.tagtraum.jipes.audio.AbstractAudioSpectrum

All Implemented Interfaces:

AudioBuffer, AudioSpectrum, Cloneable

Direct Known Subclasses:

InstantaneousFrequencySpectrum, LinearFrequencySpectrum, LogFrequencySpectrum, MelSpectrum, MultiBandSpectrum

public abstract class AbstractAudioSpectrum
extends Object
implements AudioSpectrum, Cloneable

Skeleton implementation of an AudioSpectrum.

Author:

Hendrik Schreiber

Field Summary

Fields

Modifier and Type	Field and Description
protected AudioFormat	audioFormat
protected int	frameNumber
protected float[]	imaginaryData
protected float[]	magnitudes
protected float[]	powers
protected float[]	realData

Constructor Summary

Constructors

Modifier	Constructor and Description
protected	AbstractAudioSpectrum(AbstractAudioSpectrum abstractAudioSpectrum) Copy constructor for creating exact copies of a spectrum, if you know, what class it is.
	AbstractAudioSpectrum(int frameNumber, float[] realData, float[] imaginaryData, AudioFormat audioFormat)

Method Summary

Modifier and Type	Method and Description
Object	clone() Creates an exact copy of this buffer.
protected float[]	computeMagnitudes(int length, float[] powers)
protected float[]	computePowers(int length)
AudioFormat	getAudioFormat() AudioFormat of the data this spectrum was generated from.
float[]	getData() Synonymous with getMagnitudes()
int	getFrameNumber() Number of the first frame at the beginning of this buffer.
float	getFrequency(int bin) Frequency represented by bin/index x.
float[]	getImaginaryData() Imaginary part of the spectrum (phase).
float[]	getMagnitudes() Magnitudes (square root of the powers) of the spectrum.
int	getNumberOfSamples() Number of samples.
float[]	getPowers() Powers (sum of the squares of the real and imaginary part) of the spectrum.
float[]	getRealData() Real part of the spectrum (amplitudes).
long	getTimestamp() Time from the beginning of the track to the beginning of this buffer in ms.
long	getTimestamp(TimeUnit timeUnit) Time from the beginning of the track to the beginning of this buffer in the requested unit.
protected void	reuse(int frameNumber, float[] realData, float[] imaginaryData, AudioFormat audioFormat) Refills this spectrum with new data.

Methods inherited from class java.lang.Object

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

Methods inherited from interface com.tagtraum.jipes.audio.AudioSpectrum

derive, getBin, getFrequencies

Field Detail

realData

protected float[] realData

imaginaryData

protected float[] imaginaryData

frameNumber

protected int frameNumber

audioFormat

protected AudioFormat audioFormat

magnitudes

protected float[] magnitudes

powers

protected float[] powers

Constructor Detail

AbstractAudioSpectrum

public AbstractAudioSpectrum(int frameNumber,
                             float[] realData,
                             float[] imaginaryData,
                             AudioFormat audioFormat)

AbstractAudioSpectrum

protected AbstractAudioSpectrum(AbstractAudioSpectrum abstractAudioSpectrum)

Copy constructor for creating exact copies of a spectrum, if you know, what class it is. If you don't know the exact class you might prefer clone().

Parameters:

abstractAudioSpectrum - spectrum to copy

Method Detail

reuse

protected void reuse(int frameNumber,
                     float[] realData,
                     float[] imaginaryData,
                     AudioFormat audioFormat)

Refills this spectrum with new data. This allows some object reuse. Use with care!

Parameters:

frameNumber - frame number

realData - real data

imaginaryData - imaginary data

audioFormat - audio format

getFrameNumber

public int getFrameNumber()

Description copied from interface: AudioBuffer

Number of the first frame at the beginning of this buffer. In this context a frame consists of one or more samples, depending on the number of channels. E.g. one stereo frame contains two samples.

Just like AudioBuffer.getTimestamp(), this method may not be the most accurate, if you didn't start reading at the beginning of the file.

Specified by:

getFrameNumber in interface AudioBuffer

Returns:

frame number

See Also:

AudioBuffer.getTimestamp(), AudioFormat

getTimestamp

public long getTimestamp()

Description copied from interface: AudioBuffer

Time from the beginning of the track to the beginning of this buffer in ms. For more accurate timestamps, use AudioBuffer.getTimestamp(java.util.concurrent.TimeUnit) with a finer unit.

If we didn't start reading at the beginning of the file (i.e. timestamp == 0), the offset may not be 100% precise.

Specified by:

getTimestamp in interface AudioBuffer

Returns:

time in ms or -1, if it cannot be determined

See Also:

AudioBuffer.getFrameNumber(), AudioBuffer.getTimestamp(java.util.concurrent.TimeUnit)

getTimestamp

public long getTimestamp(TimeUnit timeUnit)

Description copied from interface: AudioBuffer

Time from the beginning of the track to the beginning of this buffer in the requested unit. If we didn't start reading at the beginning of the file (i.e. timestamp == 0), the offset may not be 100% precise.

Specified by:

getTimestamp in interface AudioBuffer

Parameters:

timeUnit - time unit

Returns:

time in the given unit or -1, if it cannot be determined

See Also:

AudioBuffer.getTimestamp()

getAudioFormat

public AudioFormat getAudioFormat()

AudioFormat of the data this spectrum was generated from.

Specified by:

getAudioFormat in interface AudioBuffer

Returns:

audio formal

getRealData

public float[] getRealData()

Real part of the spectrum (amplitudes).

Specified by:

getRealData in interface AudioBuffer

Returns:

real part

getImaginaryData

public float[] getImaginaryData()

Imaginary part of the spectrum (phase).

Specified by:

getImaginaryData in interface AudioBuffer

Returns:

imaginary part

getData

public float[] getData()

Synonymous with getMagnitudes()

Specified by:

getData in interface AudioBuffer

Returns:

magnitudes of this spectrum

See Also:

getData()

getFrequency

public float getFrequency(int bin)

Frequency represented by bin/index x.

Specified by:

getFrequency in interface AudioSpectrum

Parameters:

bin - bin number

Returns:

frequency

See Also:

AudioSpectrum.getFrequencies()

getNumberOfSamples

public int getNumberOfSamples()

Number of samples.

Specified by:

getNumberOfSamples in interface AudioBuffer

Returns:

number of samples, usually getRealData().length.

computePowers

protected float[] computePowers(int length)

computeMagnitudes

protected float[] computeMagnitudes(int length,
                                    float[] powers)

getPowers

public float[] getPowers()

Powers (sum of the squares of the real and imaginary part) of the spectrum.

Specified by:

getPowers in interface AudioBuffer

Returns:

array of length numberOfSamples

See Also:

getMagnitudes()

getMagnitudes

public float[] getMagnitudes()

Magnitudes (square root of the powers) of the spectrum.

Specified by:

getMagnitudes in interface AudioBuffer

Returns:

array of length numberOfSamples

See Also:

getPowers()

clone

public Object clone()
             throws CloneNotSupportedException

Description copied from interface: AudioBuffer

Creates an exact copy of this buffer. All AudioBuffers must be cloneable.

Specified by:

clone in interface AudioBuffer

Overrides:

clone in class Object

Returns:

clone

Throws:

CloneNotSupportedException