ptolemy.media.javasound

Interface LiveSoundInterface

All Known Implementing Classes:

LiveSoundJavaSE

public interface LiveSoundInterface

Interface for implementing for implementing LiveSoundActor on different platforms.

Since:

Ptolemy II 10.0

Version:

$Id$

Author:

Ishwinder Singh

Pt.AcceptedRating:

Yellow (ishwinde)

Pt.ProposedRating:

Yellow (ishwinde)

Method Summary

Modifier and Type	Method and Description
void	addLiveSoundListener(LiveSoundListener listener) Add a live sound listener.
void	flushCaptureBuffer(java.lang.Object consumer) Flush queued data from the capture buffer.
void	flushPlaybackBuffer(java.lang.Object producer) Flush queued data from the playback buffer.
int	getBitsPerSample() Return the number of bits per audio sample, which is set by the setBitsPerSample() method.
int	getBufferSize() Return the suggested size of the internal capture and playback audio buffers, in samples per channel.
int	getBufferSizeCapture() Return the size of the internal capture audio buffer, in samples per channel.
int	getBufferSizePlayback() Return the size of the internal playback audio buffer, 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.
double[][]	getSamples(java.lang.Object consumer) Return an array of captured audio samples.
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	putSamples(java.lang.Object producer, double[][] samplesArray) Play an array of audio samples.
void	removeLiveSoundListener(LiveSoundListener listener) Remove a live sound listener.
void	resetCapture() Stop audio capture.
void	resetPlayback() Stop audio playback.
void	setBitsPerSample(int bitsPerSample) Set the number of bits per sample to use for audio capture and playback and notify any registered listeners of the change.
void	setBufferSize(int bufferSize) Request that the internal capture and playback audio buffers have bufferSize samples per channel and notify the registered listeners of the change.
void	setChannels(int channels) Set the number of audio channels to use for capture and playback and notify any registered listeners of the change.
void	setSampleRate(int sampleRate) Set the sample rate to use for audio capture and playback and notify an registered listeners of the change.
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.
void	startCapture(java.lang.Object consumer) Start audio capture.
void	startPlayback(java.lang.Object producer) Start audio playback.
void	stopCapture(java.lang.Object consumer) Stop audio capture.
void	stopPlayback(java.lang.Object producer) Stop audio playback.

Method Detail

addLiveSoundListener

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)

flushCaptureBuffer

void flushCaptureBuffer(java.lang.Object consumer)
                 throws java.io.IOException,
                        java.lang.IllegalStateException

Flush queued data from the capture buffer. The flushed data is discarded. It is only legal to flush the capture buffer after startCapture() is called. Flushing an active audio buffer is likely to cause a discontinuity in the data, resulting in a perceptible click.

Note that only the object with the exclusive lock on the capture audio resources is allowed to invoke this method. An exception will occur if the specified object does not have the lock on the playback audio resources.

Parameters:

consumer - The object that has an exclusive lock on the capture audio resources.

Throws:

java.lang.IllegalStateException - If audio capture is currently inactive. That is, if startCapture() has not yet been called or if stopCapture() has already been called.

java.io.IOException - If the calling program does not have permission to access the audio capture resources.

flushPlaybackBuffer

void flushPlaybackBuffer(java.lang.Object producer)
                  throws java.io.IOException,
                         java.lang.IllegalStateException

Flush queued data from the playback buffer. The flushed data is discarded. It is only legal to flush the playback buffer after startPlayback() is called, and only makes sense to do so (but is not required) after putSamples() is called. Flushing an active audio buffer is likely to cause a discontinuity in the data, resulting in a perceptible click.

Note that only the object with the exclusive lock on the playback audio resources is allowed to invoke this method. An exception will occur if the specified object does not have the lock on the playback audio resources.

Parameters:

producer - The object that has an exclusive lock on the playback audio resources.

Throws:

java.lang.IllegalStateException - If audio playback is currently inactive. That is, if startPlayback() has not yet been called or if stopPlayback() has already been called.

java.io.IOException - If the calling program does not have permission to access the audio playback resources.

getBitsPerSample

int getBitsPerSample()

Return the number of bits per audio sample, which is set by the setBitsPerSample() method. The default value of this parameter is 16 bits.

Returns:

The sample size in bits.

See Also:

setBitsPerSample(int)

getBufferSize

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.

See Also:

setBufferSize(int)

getBufferSizeCapture

int getBufferSizeCapture()
                  throws java.lang.IllegalStateException

Return the size of the internal capture audio buffer, in samples per channel.

Returns:

The internal buffer size in samples per channel.

Throws:

java.lang.IllegalStateException - If audio capture is inactive.

getBufferSizePlayback

int getBufferSizePlayback()

Return the size of the internal playback audio buffer, in samples per channel. This may differ from the requested buffer size if the hardware does not support the requested buffer size. If playback has not been started, then will simply return the requested buffer size.

Returns:

The internal buffer size in samples per channel.

Throws:

java.lang.IllegalStateException - If audio playback is inactive.

getChannels

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.

See Also:

setChannels(int)

getSampleRate

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.

See Also:

setSampleRate(int)

getSamples

double[][] getSamples(java.lang.Object consumer)
               throws java.io.IOException,
                      java.lang.IllegalStateException

Return an array of captured audio samples. This method should be repeatedly called to obtain audio data. The returned audio samples will have values in the range [-1, 1], regardless of the audio bit resolution (bits per sample). This method should be called often enough to prevent overflow of the internal audio buffer. If overflow occurs, some audio data will be lost but no exception or other error condition will occur. If the audio data is not yet available, then this method will block until the data is available.

The first index of the returned array represents the channel number (0 for first channel, 1 for second channel). The number of channels is set by the setChannels() method. The second index represents the sample index within a channel. For example, returned array[n][m] contains the (m+1)th sample of the (n+1)th channel. For each channel, n, the length of returned array[n] is equal to the value returned by the getTransferSize() method. The size of the 2nd dimension of the returned array is set by the setTransferSize() method.

Note that only the object with the exclusive lock on the captured audio resources is allowed to invoked this method. An exception will occur if the specified object does not have the lock on the captured audio resources.

Parameters:

consumer - The object that has an exclusive lock on the capture audio resources.

Returns:

Two dimensional array of captured audio samples.

Throws:

java.lang.IllegalStateException - If audio capture is currently inactive. That is, if startCapture() has not yet been called or if stopCapture() has already been called.

java.io.IOException - If the calling program does not have permission to access the audio capture resources.

getTransferSize

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

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

boolean isPlaybackActive()

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

Returns:

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

putSamples

void putSamples(java.lang.Object producer,
                double[][] samplesArray)
         throws java.io.IOException,
                java.lang.IllegalStateException

Play an array of audio samples. There will be a delay before the audio data is actually heard, since the audio data in samplesArray is queued to an internal audio buffer. The setBufferSize() method suggests a size for the internal buffer. An upper bound on the latency is given by (bufferSize / sampleRate) seconds. This method should be invoked often enough to prevent underflow of the internal audio buffer. Underflow is undesirable since it will cause audible gaps in audio playback, but no exception or error condition will occur. If the caller attempts to write more data than can be written, this method blocks until the data can be written to the internal audio buffer. Note that only the object with the exclusive lock on the playback audio resources is allowed to invoke this method. An exception will occur if the specified object does not have the lock on the playback audio resources.

Parameters:

producer - The object that has an exclusive lock on the playback audio resources.

samplesArray - A two dimensional array containing the samples to play or write to a file.

Throws:

java.io.IOException - If the calling program does not have permission to access the audio playback resources.

java.lang.IllegalStateException - If audio playback is currently inactive. That is, If startPlayback() has not yet been called or if stopPlayback() has already been called.

removeLiveSoundListener

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)

resetCapture

void resetCapture()

Stop audio capture. If audio capture is already inactive, then do nothing. This method should generally not be used, but it may be needed to turn of audio capture for the case where an ill-behaved application exits without calling stopCapture(). The preferred way of stopping audio capture is by calling the stopCapture() method.

resetPlayback

void resetPlayback()

Stop audio playback. If audio playback is already inactive, then do nothing. This method should generally not be used, but it may be needed to turn of audio playback for the case where an ill-behaved application exits without calling stopPlayback(). The preferred way of stopping audio playback is by calling the stopPlayback() method.

setBitsPerSample

void setBitsPerSample(int bitsPerSample)
               throws java.io.IOException

Set the number of bits per sample to use for audio capture and playback and notify any registered listeners of the change. Allowable values include 8 and 16 bits. If this method is not invoked, then the default value of 16 bits is used.

Parameters:

bitsPerSample - The number of bits per sample.

Throws:

java.io.IOException - If the specified bits per sample is not supported by the audio hardware or by Java.

See Also:

getBitsPerSample()

setBufferSize

void setBufferSize(int bufferSize)
            throws java.io.IOException

Request that the internal capture and playback audio buffers have bufferSize samples per channel and notify the registered listeners of the change. If this method is not invoked, the default value of 1024 is used.

Parameters:

bufferSize - The suggested size of the internal capture and playback audio buffers, in samples per channel.

Throws:

java.io.IOException - If the specified number of channels is not supported by the audio hardware or by Java.

See Also:

getBufferSize()

setChannels

void setChannels(int channels)
          throws java.io.IOException

Set the number of audio channels to use for capture and playback and notify any registered listeners of the change. Allowable values are 1 (for mono) and 2 (for stereo). If this method is not invoked, the default value of 1 audio channel is used. Note that this method sets the size of the first dimension of the 2-dimensional array used by the putSamples() and getSamples() methods.

Parameters:

channels - The number audio channels.

Throws:

java.io.IOException - If the specified number of channels is not supported by the audio hardware or by Java.

See Also:

getChannels()

setSampleRate

void setSampleRate(int sampleRate)
            throws java.io.IOException

Set the sample rate to use for audio capture and playback and notify an registered listeners of the change. Allowable values for this parameter are 8000, 11025, 22050, 44100, and 48000 Hz. If this method is not invoked, then the default value of 8000 Hz is used.

Parameters:

sampleRate - Sample rate in Hz.

Throws:

java.io.IOException - If the specified sample rate is not supported by the audio hardware or by Java.

See Also:

getSampleRate()

setTransferSize

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()

startCapture

void startCapture(java.lang.Object consumer)
           throws java.io.IOException,
                  java.lang.IllegalStateException

Start audio capture. The specified object will be given an exclusive lock on the audio capture resources until the stopCapture() method is called with the same object reference. After this method returns, the getSamples() method may be repeatedly invoked (using the object reference as a parameter) to capture audio.

If audio capture is already active, then an exception will occur.

Parameters:

consumer - The object to be given exclusive access to the captured audio resources.

Throws:

java.io.IOException - If another object currently has access to the audio capture resources or if starting the capture or playback throws it.

java.lang.IllegalStateException - If this method is called while audio capture is already active.

startPlayback

void startPlayback(java.lang.Object producer)
            throws java.io.IOException,
                   java.lang.IllegalStateException

Start audio playback. The specified object will be given an exclusive lock on the audio playback resources until the stopPlayback() method is called with the same object reference. After this method returns, the putSamples() method may be repeatedly invoked (using the object reference as a parameter) to playback audio.

If audio playback is already active, then an exception will occur.

Parameters:

producer - The object to be given exclusive access to the playback resources.

Throws:

java.io.IOException - If another object currently has access to the audio capture resources or if starting the playback throws it.

java.lang.IllegalStateException - If this method is called while audio playback is already active.

stopCapture

void stopCapture(java.lang.Object consumer)
          throws java.io.IOException,
                 java.lang.IllegalStateException

Stop audio capture. If the specified object has the lock on audio capture when this method is invoked, then stop audio capture. Otherwise an exception will occur.

Parameters:

consumer - The object that held on exclusive lock on the captured audio resources when this method was invoked.

Throws:

java.io.IOException - If another object currently has access to the audio capture resources or if stopping the capture throws it.

java.lang.IllegalStateException - If the specified object did not hold an exclusive lock on the captured audio resources when this method was invoked.

stopPlayback

void stopPlayback(java.lang.Object producer)
           throws java.io.IOException,
                  java.lang.IllegalStateException

Stop audio playback. If the specified object has the lock on audio playback when this method is invoked, then stop audio playback. Otherwise an exception will occur.

Parameters:

producer - The object that held on exclusive lock on the playback audio resources when this method was invoked.

Throws:

java.io.IOException - If another object currently has access to the audio capture resources or if stopping the playback throws it.

java.lang.IllegalStateException - If the specified object did not hold an exclusive lock on the playback audio resources when this method was invoked.