paulscode.sound
Class Channel

java.lang.Object
  paulscode.sound.Channel

Direct Known Subclasses:

ChannelJavaSound, ChannelJOAL, ChannelLWJGLOpenAL

public class Channel
extends java.lang.Object

The Channel class is the base class which can be extended for library-specific channels. It is also used in the "no-sound" library. A channel is a reserved sound-card voice through which sources are played back. Channels can be either streaming channels or normal (non-streaming) ones. For consistant naming conventions, each sub-class should have the name prefix "Channel".

SoundSystem License:

You are free to use this library for any purpose, commercial or otherwise. You may modify this library or source code, and distribute it any way you like, provided the following conditions are met:
1) You may not falsely claim to be the author of this library or any unmodified portion of it.
2) You may not copyright this library or a modified version of it and then sue me for copyright infringement.
3) If you modify the source code, you must clearly document the changes made before redistributing the modified source code, so other users know it is not the original code.
4) You are not required to give me credit for this library in any derived work, but if you do, you must also mention my website: http://www.paulscode.com
5) I the author will not be responsible for any damages (physical, financial, or otherwise) caused by the use if this library or any part of it.
6) I the author do not guarantee, warrant, or make any representations, either expressed or implied, regarding the use of this library or any part of it.

Author: Paul Lamb
http://www.paulscode.com

Field Summary

Source	attachedSource Whatever source is attached to this channel.
int	buffersUnqueued Cumulative counter of the buffers played then unqued.
int	channelType Global identifier for the type of channel (normal or streaming).
protected java.lang.Class	libraryType The library class associated with this type of channel.

Constructor Summary

Channel(int type)
Constructor: Takes channelType identifier as a paramater.

Method Summary

int	buffersProcessed() Returns the number of queued byte[] buffers that have finished playing.
void	cleanup() Shuts the channel down and removes references to all instantiated objects.
void	close() Stops the channel, dequeues any queued data, and closes the channel.
protected boolean	errorCheck(boolean error, java.lang.String message) Prints the specified message if error is true.
protected void	errorMessage(java.lang.String message) Prints an error message.
int	feedRawAudioData(byte[] buffer) Feeds raw data to the stream.
void	flush() Dequeues all previously queued data.
java.lang.String	getClassName() Returns the name of the class.
protected void	importantMessage(java.lang.String message) Prints an important message.
protected void	message(java.lang.String message) Prints a message.
float	millisecondsPlayed() Calculates the number of milliseconds since the channel began playing.
void	pause() Temporarily stops playback for this channel.
void	play() Plays the currently attached normal source, opens this channel up for streaming, or resumes playback if this channel was paused.
boolean	playing() Used to determine if a channel is actively playing a source.
boolean	preLoadBuffers(java.util.LinkedList<byte[]> bufferList) Queues up the initial byte[] buffers of data to be streamed.
protected void	printStackTrace(java.lang.Exception e) Prints an exception's error message followed by the stack trace.
boolean	processBuffer() Plays the next queued byte[] buffer.
boolean	queueBuffer(byte[] buffer) Queues up a byte[] buffer of data to be streamed.
void	rewind() Rewinds the attached source to the beginning.
void	setAudioFormat(javax.sound.sampled.AudioFormat audioFormat) Sets the channel up to receive the specified audio format.
void	stop() Stops playback for this channel and rewinds the attached source to the beginning.

Methods inherited from class java.lang.Object

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

Field Detail

libraryType

protected java.lang.Class libraryType

The library class associated with this type of channel.

channelType

public int channelType

Global identifier for the type of channel (normal or streaming). Possible values for this varriable can be found in the SoundSystemConfig class.

attachedSource

public Source attachedSource

Whatever source is attached to this channel.

buffersUnqueued

public int buffersUnqueued

Cumulative counter of the buffers played then unqued.

Constructor Detail

Channel

public Channel(int type)

Constructor: Takes channelType identifier as a paramater. Possible values for channel type can be found in the SoundSystemConfig class.

Parameters:

type - Type of channel (normal or streaming).

Method Detail

cleanup

public void cleanup()

Shuts the channel down and removes references to all instantiated objects.

preLoadBuffers

public boolean preLoadBuffers(java.util.LinkedList<byte[]> bufferList)

Queues up the initial byte[] buffers of data to be streamed.

Parameters:

bufferList - List of the first buffers to be played for a streaming source.

Returns:

False if an error occurred or if end of stream was reached.

queueBuffer

public boolean queueBuffer(byte[] buffer)

Queues up a byte[] buffer of data to be streamed.

Parameters:

buffer - The next buffer to be played for a streaming source.

Returns:

False if an error occurred or if the channel is shutting down.

feedRawAudioData

public int feedRawAudioData(byte[] buffer)

Feeds raw data to the stream.

Parameters:

buffer - Buffer containing raw audio data to stream.

Returns:

Number of prior buffers that have been processed.

buffersProcessed

public int buffersProcessed()

Returns the number of queued byte[] buffers that have finished playing.

Returns:

Number of buffers processed.

millisecondsPlayed

public float millisecondsPlayed()

Calculates the number of milliseconds since the channel began playing.

Returns:

Milliseconds, or -1 if unable to calculate.

processBuffer

public boolean processBuffer()

Plays the next queued byte[] buffer. This method is run from the seperate StreamThread.

Returns:

False when no more buffers are left to process.

setAudioFormat

public void setAudioFormat(javax.sound.sampled.AudioFormat audioFormat)

Sets the channel up to receive the specified audio format.

flush

public void flush()

Dequeues all previously queued data.

close

public void close()

Stops the channel, dequeues any queued data, and closes the channel.

play

public void play()

Plays the currently attached normal source, opens this channel up for streaming, or resumes playback if this channel was paused.

pause

public void pause()

Temporarily stops playback for this channel.

stop

public void stop()

Stops playback for this channel and rewinds the attached source to the beginning.

rewind

public void rewind()

Rewinds the attached source to the beginning. Stops the source if it was paused.

playing

public boolean playing()

Used to determine if a channel is actively playing a source. This method will return false if the channel is paused or stopped and when no data is queued to be streamed.

Returns:

True if this channel is playing a source.

getClassName

public java.lang.String getClassName()

Returns the name of the class.

Returns:

"Channel" + library title.

message

protected void message(java.lang.String message)

Prints a message.

Parameters:

message - Message to print.

importantMessage

protected void importantMessage(java.lang.String message)

Prints an important message.

Parameters:

message - Message to print.

errorCheck

protected boolean errorCheck(boolean error,
                             java.lang.String message)

Prints the specified message if error is true.

Parameters:

error - True or False.

message - Message to print if error is true.

Returns:

True if error is true.

errorMessage

protected void errorMessage(java.lang.String message)

Prints an error message.

Parameters:

message - Message to print.

printStackTrace

protected void printStackTrace(java.lang.Exception e)

Prints an exception's error message followed by the stack trace.

Parameters:

e - Exception containing the information to print.