ptolemy.media.javasound

Class LiveSoundCommon

java.lang.Object

ptolemy.media.javasound.LiveSoundCommon

Direct Known Subclasses:

LiveSoundJavaSE

public class LiveSoundCommon
extends java.lang.Object

Class containing the platform independent code of LiveSound actor.

Since:

Ptolemy II 10.0

Author:

Brian K. Vogel and Neil E. Turner and Steve Neuendorffer, Edward A. Lee, Contributor: Dennis Geurts, Ishwinder Singh

Pt.AcceptedRating:

Red (ishwinde)

Pt.ProposedRating:

Red (ishwinde)

Field Summary

Fields

Modifier and Type	Field and Description
protected double[][]	_audioInDoubleArray Array of audio samples in double format.
protected int	_bitsPerSample The number of bits per sample.
protected int	_bufferSize The requested buffer size in samples per channel.
protected int	_bytesPerSample The number of bytes per sample, default 2.
protected byte[]	_captureData Array of audio samples in byte format.
protected boolean	_captureIsActive true is audio capture is currently active.
protected int	_channels The number of channels.
protected java.util.List	_liveSoundListeners The list of listeners.
protected double	_maxSample Cached value of the maximum integer value, default for 16 bits.
protected double	_maxSampleReciprocal Cached value of the maximum value scaling factor, default for 16 bits.
protected byte[]	_playbackData Byte buffer used for playback data.
protected boolean	_playbackIsActive true is audio playback is currently active.
protected float	_sampleRate The sample rate.
protected java.util.List	_soundConsumers The list of sound consumers.
protected int	_transferSize The number of audio samples to transfer per channel when getSamples() is invoked.

Constructor Summary

Constructors

Constructor and Description
LiveSoundCommon()

Method Summary

Modifier and Type	Method and Description
protected void	_byteArrayToDoubleArray(double[][] doubleArray, byte[] byteArray) Convert a byte array of audio samples in linear signed PCM big endian format into a double array of audio samples (-1, 1) range.
protected byte[]	_doubleArrayToByteArray(double[][] doubleArray) Convert a double array of audio samples into a byte array of audio samples in linear signed PCM big endian format.
protected void	_notifyLiveSoundListeners(int parameter) Notify the live sound listeners about a change in an audio parameter.
void	addLiveSoundListener(LiveSoundListener listener) Add a live sound listener.
int	getBitsPerSample() Return the number of bits per sample.
int	getBufferSize() Return the suggested size of the internal capture and playback audio buffers, in samples per channel.
int	getChannels() Return the number of audio channels, which is set by the setChannels() method.
int	getSampleRate() Return the current sampling rate in Hz, which is set by the setSampleRate() method.
int	getTransferSize() Get the array length (in samples per channel) to use for capturing and playing samples via the putSamples() and getSamples() methods.
boolean	isCaptureActive() Return true if audio capture is currently active.
boolean	isPlaybackActive() Return true if audio playback is currently active.
void	removeLiveSoundListener(LiveSoundListener listener) Remove a live sound listener.
void	setTransferSize(int transferSize) Set the array length (in samples per channel) to use for capturing and playing samples via the putSamples() and getSamples() methods.

Methods inherited from class java.lang.Object

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

Field Detail

_audioInDoubleArray

protected double[][] _audioInDoubleArray

Array of audio samples in double format.

_bitsPerSample

protected int _bitsPerSample

The number of bits per sample. Default is 16.

_bufferSize

protected int _bufferSize

The requested buffer size in samples per channel.

_bytesPerSample

protected int _bytesPerSample

The number of bytes per sample, default 2.

_captureIsActive

protected boolean _captureIsActive

true is audio capture is currently active.

_channels

protected int _channels

The number of channels. Deafult is 1.

_captureData

protected byte[] _captureData

Array of audio samples in byte format.

_playbackData

protected byte[] _playbackData

Byte buffer used for playback data.

_liveSoundListeners

protected java.util.List _liveSoundListeners

The list of listeners.

_maxSampleReciprocal

protected double _maxSampleReciprocal

Cached value of the maximum value scaling factor, default for 16 bits.

_maxSample

protected double _maxSample

Cached value of the maximum integer value, default for 16 bits.

_playbackIsActive

protected boolean _playbackIsActive

true is audio playback is currently active.

_sampleRate

protected float _sampleRate

The sample rate.

_soundConsumers

protected java.util.List _soundConsumers

The list of sound consumers.

_transferSize

protected int _transferSize

The number of audio samples to transfer per channel when getSamples() is invoked.

Constructor Detail

LiveSoundCommon

public LiveSoundCommon()

Method Detail

addLiveSoundListener

public void addLiveSoundListener(LiveSoundListener listener)

Add a live sound listener. The listener will be notified of all changes in live audio parameters. If the listener is already listening, then do nothing.

Parameters:

listener - The LiveSoundListener to add.

See Also:

removeLiveSoundListener(LiveSoundListener)

getBitsPerSample

public int getBitsPerSample()

Return the number of bits per sample.

Returns:

The number of bits per sample, which in this base class defaults to 16.

getBufferSize

public int getBufferSize()

Return the suggested size of the internal capture and playback audio buffers, in samples per channel. This parameter is set by the setBufferSize() method. There is no guarantee that the value returned is the actual buffer size used for capture and playback. Furthermore, the buffers used for capture and playback may have different sizes. The default value of this parameter is 4096.

Returns:

The suggested internal buffer size in samples per channel.

getChannels

public int getChannels()

Return the number of audio channels, which is set by the setChannels() method. The default value of this parameter is 1 (for mono audio).

Returns:

The number of audio channels.

getSampleRate

public int getSampleRate()

Return the current sampling rate in Hz, which is set by the setSampleRate() method. The default value of this parameter is 8000 Hz.

Returns:

The sample rate in Hz.

getTransferSize

public int getTransferSize()

Get the array length (in samples per channel) to use for capturing and playing samples via the putSamples() and getSamples() methods. This method gets the size of the 2nd dimension of the 2-dimensional array used by the putSamples() and getSamples() methods. This method returns the value that was set by the setTransferSize(). If setTransferSize() was not invoked, the default value of 128 is returned.

Returns:

The size of the 2nd dimension of the 2-dimensional array used by the putSamples() and getSamples() methods.

See Also:

setTransferSize(int)

isCaptureActive

public boolean isCaptureActive()

Return true if audio capture is currently active. Otherwise return false.

Returns:

True If audio capture is currently active. Otherwise return false.

isPlaybackActive

public boolean isPlaybackActive()

Return true if audio playback is currently active. Otherwise return false.

Returns:

True If audio playback is currently active. Otherwise return false.

removeLiveSoundListener

public void removeLiveSoundListener(LiveSoundListener listener)

Remove a live sound listener. If the listener is is not listening, then do nothing.

Parameters:

listener - The LiveSoundListener to remove.

See Also:

addLiveSoundListener(LiveSoundListener)

setTransferSize

public void setTransferSize(int transferSize)
                     throws java.lang.IllegalStateException

Set the array length (in samples per channel) to use for capturing and playing samples via the putSamples() and getSamples() methods. This method sets the size of the 2nd dimension of the 2-dimensional array used by the putSamples() and getSamples() methods. If this method is not invoked, the default value of 128 is used.

This method should only be called while audio capture and playback are inactive. Otherwise an exception will occur.

Parameters:

transferSize - The size of the 2nd dimension of the 2-dimensional array used by the putSamples() and getSamples() methods

Throws:

java.lang.IllegalStateException - If this method is called while audio capture or playback are active.

See Also:

getTransferSize()

_byteArrayToDoubleArray

protected void _byteArrayToDoubleArray(double[][] doubleArray,
                                       byte[] byteArray)

Convert a byte array of audio samples in linear signed PCM big endian format into a double array of audio samples (-1, 1) range.

Parameters:

doubleArray - The resulting array of doubles.

byteArray - The linear signed pcm big endian byte array formatted array representation of audio data.

_doubleArrayToByteArray

protected byte[] _doubleArrayToByteArray(double[][] doubleArray)

Convert a double array of audio samples into a byte array of audio samples in linear signed PCM big endian format. The samples contained in doubleArray should be in the range (-1, 1). Samples outside this range will be hard clipped to the range (-1, 1).

Parameters:

doubleArray - Two dimensional array holding audio samples. For each channel, m, doubleArray[m] is a single dimensional array containing samples for channel m. All channels are required to have the same number of samples, but this is not checked.

Returns:

The linear signed PCM big endian byte array formatted array representation of doubleArray. The length of the returned array is (doubleArray[i].length*bytesPerSample*channels).

_notifyLiveSoundListeners

protected void _notifyLiveSoundListeners(int parameter)

Notify the live sound listeners about a change in an audio parameter.

Parameters:

parameter - The audio parameter of LiveSound that has changed. The value of parameter should be one of LiveSoundEvent.SAMPLE_RATE, LiveSoundEvent.CHANNELS, LiveSoundEvent.BUFFER_SIZE, or LiveSoundEvent.BITS_PER_SAMPLE.