at.ofai.music.beatroot
Class AudioPlayer

java.lang.Object
  at.ofai.music.beatroot.AudioPlayer

All Implemented Interfaces:

java.lang.Runnable

public class AudioPlayer
extends java.lang.Object
implements java.lang.Runnable

Field Summary

protected javax.sound.sampled.SourceDataLine	audioOut The object to which audio output is written
protected int	beatIndex The index in beats[] of the next beat (relative to the current playback position
protected long[]	beats The positions in samples of beats for playback of audio with click marking beat times
protected int[][]	click An array of percussion sounds
protected AudioFile	currentFile The file currently loaded by this AudioPlayer
protected long	currentPosition The position (in bytes) of playback, relative to the beginning of the file
protected boolean	debug Flag for debugging output
protected static int	defaultOutputBufferSize The default buffer size for audio output
protected long	endPosition The byte position in the current file to stop playing
protected GUI	gui BeatRoot's graphical user interface
protected javax.swing.JFileChooser	jfc The file chooser dialog window for opening and saving files
protected int[]	level The metrical level of each beat (see beats[])
protected int	outputBufferSize The buffer size used by audioOut
protected boolean	playAudio Flag indicating the current mode of playing, whether audio should be played
protected boolean	playBeats Flag indicating the current mode of playing, whether the beats should be played
protected boolean	playing A flag set by the play thread indicating whether audio playback is active
protected byte[]	readBuffer Audio input buffer for the current input file
protected byte[]	readBuffer2 A second audio input buffer used when crossfading between two audio files
protected static int	readBufferSize The size of the buffer for reading audio input
protected AudioFile	requestedFile A new file that has been loaded to play next
protected long	requestedPosition The requested playback position, in bytes, relative to the beginning of the file
protected long	startNanoTime The time that the audio playback last started, in nanoseconds
protected double	startTime The time in the playback file where the audio playback last started
protected boolean	stopRequested A flag indicating to the play thread that playing should stop
protected static double	volume The relative volume of percussion (for the click track) relative to the input audio

Constructor Summary

AudioPlayer(AudioFile f, javax.swing.JFileChooser ch)
Constructor

Method Summary

protected void	addBeat(byte[] buffer, int offset, int len, int level) Adds a percussion sound to an audio sample at a specified time.
protected void	addBeats(byte[] buffer, int bytes) Adds a sequence of percussive sounds marking the beats at various metrical levels to an audio sample.
long	correctedPosition() Returns current playback position, corrected for audio buffered in the soundcard.
long	getCurrentFileLength() Returns the length of the current or requested file.
double	getCurrentTime() Returns the current playback time in seconds from when play was started.
void	ifSetPosition(double time) Conditionally changes the position and possibly the file for input data, if the play thread is idle.
protected void	initBeats() Initialise the beat list ready for audio playback with beats.
protected void	initClicks() Initialise the percussion sounds for audio playback with beats.
void	load() Open a new audio input file, with the path being chosen by a file chooser dialog.
void	load(java.lang.String fileName) Open a new audio input file with the given path.
void	pause() Notifies play thread to pause playing
void	play() Notify play thread to play audio with beats
void	play(boolean audioOnly) Notify play thread to play either audio or beats.
void	play(boolean audio, boolean beats) Notify play thread to play audio, beats or both.
void	run() Implements the Runnable interface for the audio playback thread.
void	save() Saves audio with beats as a WAV file, with name determined by a file chooser dialog.
void	setCurrentFile(AudioFile newFile) Change the input file for audio playback (in a thread-safe way).
protected void	setPosition(long positionRequested) Changes the position and possibly the file for input data, and updates the GUI accordingly.
protected void	setPosition(long positionRequested, boolean update) Changes the position and possibly the file for input data.
void	skip(double time) Changes the playback position relative to the current playback position.
void	skip(long bytes) Changes the playback position relative to the current playback position.
void	stop() Notifies play thread to stop playing or reset position if not playing.
void	stop(boolean resetPosition) Notifies play thread to stop playing.
void	togglePlay() Notifies the play thread to pause if playing or play if paused/stopped.

Methods inherited from class java.lang.Object

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

Field Detail

jfc

protected javax.swing.JFileChooser jfc

The file chooser dialog window for opening and saving files

gui

protected GUI gui

BeatRoot's graphical user interface

currentFile

protected AudioFile currentFile

The file currently loaded by this AudioPlayer

requestedFile

protected AudioFile requestedFile

A new file that has been loaded to play next

currentPosition

protected long currentPosition

The position (in bytes) of playback, relative to the beginning of the file

requestedPosition

protected long requestedPosition

The requested playback position, in bytes, relative to the beginning of the file

endPosition

protected long endPosition

The byte position in the current file to stop playing

startNanoTime

protected long startNanoTime

The time that the audio playback last started, in nanoseconds

startTime

protected double startTime

The time in the playback file where the audio playback last started

stopRequested

protected boolean stopRequested

A flag indicating to the play thread that playing should stop

playing

protected boolean playing

A flag set by the play thread indicating whether audio playback is active

audioOut

protected javax.sound.sampled.SourceDataLine audioOut

The object to which audio output is written

outputBufferSize

protected int outputBufferSize

The buffer size used by audioOut

readBuffer

protected byte[] readBuffer

Audio input buffer for the current input file

readBuffer2

protected byte[] readBuffer2

A second audio input buffer used when crossfading between two audio files

beats

protected long[] beats

The positions in samples of beats for playback of audio with click marking beat times

level

protected int[] level

The metrical level of each beat (see beats[])

beatIndex

protected int beatIndex

The index in beats[] of the next beat (relative to the current playback position

click

protected int[][] click

An array of percussion sounds

readBufferSize

protected static final int readBufferSize

The size of the buffer for reading audio input

See Also:

Constant Field Values

defaultOutputBufferSize

protected static final int defaultOutputBufferSize

The default buffer size for audio output

See Also:

Constant Field Values

volume

protected static double volume

The relative volume of percussion (for the click track) relative to the input audio

debug

protected boolean debug

Flag for debugging output

playAudio

protected boolean playAudio

Flag indicating the current mode of playing, whether audio should be played

playBeats

protected boolean playBeats

Flag indicating the current mode of playing, whether the beats should be played

Constructor Detail

AudioPlayer

public AudioPlayer(AudioFile f,
                   javax.swing.JFileChooser ch)

Constructor

Parameters:

f - The input audio file

ch - The FileChooser object for opening and saving files

Method Detail

play

public void play()

Notify play thread to play audio with beats

play

public void play(boolean audioOnly)

Notify play thread to play either audio or beats.

Parameters:

audioOnly - Flag indicating whether to play audio (true) or play beats (false)

play

public void play(boolean audio,
                 boolean beats)

Notify play thread to play audio, beats or both.

Parameters:

audio - Flag indicating whether audio should be played

beats - Flag indicating whether beats should be played

pause

public void pause()

Notifies play thread to pause playing

stop

public void stop(boolean resetPosition)

Notifies play thread to stop playing.

Parameters:

resetPosition - Flag indicating whether to reset the playback position to the beginning of the file

stop

public void stop()

Notifies play thread to stop playing or reset position if not playing.

togglePlay

public void togglePlay()

Notifies the play thread to pause if playing or play if paused/stopped.

setPosition

protected void setPosition(long positionRequested)

Changes the position and possibly the file for input data, and updates the GUI accordingly.

Parameters:

positionRequested - The new file position (in bytes) for audio input

setPosition

protected void setPosition(long positionRequested,
                           boolean update)

Changes the position and possibly the file for input data.

Parameters:

positionRequested - The new file position (in bytes) for audio input

update - Flag to indicate whether the GUI should be updated or not

ifSetPosition

public void ifSetPosition(double time)

Conditionally changes the position and possibly the file for input data, if the play thread is idle. The GUI is not updated.

Parameters:

time - New play position (in seconds)

skip

public void skip(double time)

Changes the playback position relative to the current playback position.

Parameters:

time - Offset of new play position (in seconds) relative to present play position.

skip

public void skip(long bytes)

Changes the playback position relative to the current playback position.

Parameters:

bytes - Offset of new play position (in bytes) relative to present play position.

getCurrentTime

public double getCurrentTime()

Returns the current playback time in seconds from when play was started. Note that DataLine.getLongFramePosition() is not reliable - it counts in units of output buffers or simple fractions thereof - i.e. what has been sent to the soundcard rather than what has been rendered by the soundcard.

Returns:

Playback time in seconds

correctedPosition

public long correctedPosition()

Returns current playback position, corrected for audio buffered in the soundcard.

Returns:

Current playback position in bytes relative to the beginning of the file.

getCurrentFileLength

public long getCurrentFileLength()

Returns the length of the current or requested file.

Returns:

Length in bytes of the current or requested audio input file.

save

public void save()

Saves audio with beats as a WAV file, with name determined by a file chooser dialog.

load

public void load()

Open a new audio input file, with the path being chosen by a file chooser dialog.

load

public void load(java.lang.String fileName)

Open a new audio input file with the given path.

Parameters:

fileName - The relative or absolate path name of the new audio input file.

setCurrentFile

public void setCurrentFile(AudioFile newFile)

Change the input file for audio playback (in a thread-safe way).

Parameters:

newFile - The new input file.

run

public void run()

Implements the Runnable interface for the audio playback thread. This method has two loops: an outer "request" loop and an inner "play" loop. The outer loop waits for a signal (notify()) from the play() method, and then initialises audio output and click track data, and enters the inner play loop. The inner loop reads audio from the input file and writes to the audio device, exiting only at the end of file or an external request to stop or pause playback, or to switch playback to a new file.

Specified by:

run in interface java.lang.Runnable

initClicks

protected void initClicks()

Initialise the percussion sounds for audio playback with beats. Reads each of the sounds into an array for quick and simple playback.

initBeats

protected void initBeats()

Initialise the beat list ready for audio playback with beats. Copies beats into an array for quick and simple retrieval during playback. Might not be the best solution; e.g. direct use of the beat list would be possible if checks were made for concurrent modification

addBeats

protected void addBeats(byte[] buffer,
                        int bytes)

Adds a sequence of percussive sounds marking the beats at various metrical levels to an audio sample.

Parameters:

buffer - The audio sample without beats

bytes - The length of the audio sample in bytes

addBeat

protected void addBeat(byte[] buffer,
                       int offset,
                       int len,
                       int level)

Adds a percussion sound to an audio sample at a specified time.

Parameters:

buffer - The audio sample without the beats being marked

offset - Offset of the percussion sound relative to the audio sample

len - Length of the sound to add (in bytes)

level - Metrical level of the percussion sound (determines instrument)