BeatRoot

Field Detail

• audioOut

  protected javax.sound.sampled.SourceDataLine audioOut

  The object to which audio output is written

• beatIndex

  protected int beatIndex

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

• beats

  protected long[] beats

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

• click

  protected int[][] click

  An array of percussion sounds

• currentFile

  protected AudioFile currentFile

  The file currently loaded by this AudioPlayer

• currentPosition

  protected long currentPosition

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

• debug

  protected boolean debug

  Flag for debugging output

• defaultOutputBufferSize

  protected static final int defaultOutputBufferSize

  The default buffer size for audio output

  See Also:

  Constant Field Values

• endPosition

  protected long endPosition

  The byte position in the current file to stop playing

• gui

  protected GUI gui

  BeatRoot's graphical user interface

• jfc

  protected javax.swing.JFileChooser jfc

  The file chooser dialog window for opening and saving files

• level

  protected int[] level

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

• outputBufferSize

  protected int outputBufferSize

  The buffer size used by audioOut

• 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

• playing

  protected boolean playing

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

• 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

• readBufferSize

  protected static final int readBufferSize

  The size of the buffer for reading audio input

  See Also:

  Constant Field Values

• requestedFile

  protected AudioFile requestedFile

  A new file that has been loaded to play next

• requestedPosition

  protected long requestedPosition

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

• 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

• volume

  protected static double volume

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

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)