Package com.sun.speech.freetts.audio

Class JavaStreamingAudioPlayer

java.lang.Object
com.sun.speech.freetts.audio.JavaStreamingAudioPlayer
All Implemented Interfaces:
AudioPlayer
public class JavaStreamingAudioPlayer extends Object implements AudioPlayer
Streams audio to java audio. This class provides a low latency method of sending audio output through the javax.sound audio API. Audio data is sent in small sets to the audio system allowing it to be played soon after it is generated. Unfortunately, the current release of the JDK (JDK 1.4 beta 2) has a bug or two in the implementation of 'SourceDataLine.drain'. A workaround solution that sleep/waits on SourceDataLine.isActive is used here instead. To disable the work around (i.e use the real 'drain') set the property:

com.sun.speech.freetts.audio.AudioPlayer.drainWorksProperly; to true. If the workaround is enabled, the line.isActive method will be performed periodically. The period of the test can be controlled with:

com.sun.speech.freetts.audio.AudioPlayer.drainDelay"

The default if 5ms.

The property com.sun.speech.freetts.audio.AudioPlayer.bufferSize"

Controls the audio buffer size, it defaults to 8192

Even with this drain work around, there are some issues with this class. The workaround drain is not completely reliable. A resume following a pause does not always continue at the proper position in the audio. On a rare occasion, sound output will be repeated a number of times. This may be related to bug 4421330 in the Bug Parade database.

  • Constructor Summary

    Constructors
    Constructor
    Description
    JavaStreamingAudioPlayer()
    Constructs a default JavaStreamingAudioPlayer

  • Method Summary

    Modifier and Type
    Method
    Description
    void
    begin(int size)
    Starts the output of a set of data.
    void
    cancel()
    Cancels currently playing audio.
    void
    close()
    Closes this audio player
    boolean
    drain()
    Waits for all queued audio to be played
    boolean
    end()
    Marks the end of a set of data.
    AudioFormat
    getAudioFormat()
    Gets the audio format for this player
    long
    getTime()
    Gets the amount of played since the last mark
    float
    getVolume()
    Returns the current volume.
    void
    pause()
    Pauses audio output
    void
    reset()
    Prepares for another batch of output.
    void
    resetTime()
    Resets the audio clock
    void
    resume()
    Resumes audio output
    void
    setAudioFormat(AudioFormat format)
    Sets the audio format for this player
    void
    setVolume(float volume)
    Sets the current volume.
    void
    showMetrics()
    Shows metrics for this audio player
    void
    startFirstSampleTimer()
    Starts the first sample timer
    String
    toString()
    Returns the name of this audioplayer
    boolean
    write(byte[] audioData)
    Writes the given bytes to the audio stream
    boolean
    write(byte[] bytes, int offset, int size)
    Writes the given bytes to the audio stream

    Methods inherited from class java.lang.Object

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

  • Constructor Details

    • JavaStreamingAudioPlayer

      public JavaStreamingAudioPlayer()
      Constructs a default JavaStreamingAudioPlayer

  • Method Details

    • setAudioFormat

      public void setAudioFormat(AudioFormat format)
      Sets the audio format for this player
      Specified by:
      setAudioFormat in interface AudioPlayer
      Parameters:
      format - the audio format
      Throws:
      UnsupportedOperationException - if the line cannot be opened with the given format

    • getAudioFormat

      public AudioFormat getAudioFormat()
      Gets the audio format for this player
      Specified by:
      getAudioFormat in interface AudioPlayer
      Returns:
      format the audio format

    • startFirstSampleTimer

      public void startFirstSampleTimer()
      Starts the first sample timer
      Specified by:
      startFirstSampleTimer in interface AudioPlayer

    • pause

      public void pause()
      Pauses audio output
      Specified by:
      pause in interface AudioPlayer

    • resume

      public void resume()
      Resumes audio output
      Specified by:
      resume in interface AudioPlayer

    • cancel

      public void cancel()
      Cancels currently playing audio.
      Specified by:
      cancel in interface AudioPlayer

    • reset

      public void reset()
      Prepares for another batch of output. Larger groups of output (such as all output associated with a single FreeTTSSpeakable) should be grouped between a reset/drain pair.
      Specified by:
      reset in interface AudioPlayer

    • close

      public void close()
      Closes this audio player
      Specified by:
      close in interface AudioPlayer

    • getVolume

      public float getVolume()
      Returns the current volume.
      Specified by:
      getVolume in interface AudioPlayer
      Returns:
      the current volume (between 0 and 1)

    • setVolume

      public void setVolume(float volume)
      Sets the current volume.
      Specified by:
      setVolume in interface AudioPlayer
      Parameters:
      volume - the current volume (between 0 and 1)

    • begin

      public void begin(int size)
      Starts the output of a set of data. For this JavaStreamingAudioPlayer, it actually opens the audio line. Since this is a streaming audio player, the size parameter has no meaning and effect at all, so any value can be used. Audio data for a single utterance should be grouped between begin/end pairs.
      Specified by:
      begin in interface AudioPlayer
      Parameters:
      size - supposedly the size of data between now and the end, but since this is a streaming audio player, this parameter has no meaning and effect at all

    • end

      public boolean end()
      Marks the end of a set of data. Audio data for a single utterance should be groupd between begin/end pairs.
      Specified by:
      end in interface AudioPlayer
      Returns:
      true if the audio was output properly, false if the output was cancelled or interrupted.

    • drain

      public boolean drain()
      Waits for all queued audio to be played
      Specified by:
      drain in interface AudioPlayer
      Returns:
      true if the audio played to completion, false if the audio was stopped [[[ WORKAROUND TODO The javax.sound.sampled drain is almost working properly. On linux, there is still a little bit of sound that needs to go out, even after drain is called. Thus, the drainDelay. We wait for a few hundred milliseconds while the data is really drained out of the system ]]]

    • getTime

      public long getTime()
      Gets the amount of played since the last mark
      Specified by:
      getTime in interface AudioPlayer
      Returns:
      the amount of audio in milliseconds

    • resetTime

      public void resetTime()
      Resets the audio clock
      Specified by:
      resetTime in interface AudioPlayer

    • write

      public boolean write(byte[] audioData)
      Writes the given bytes to the audio stream
      Specified by:
      write in interface AudioPlayer
      Parameters:
      audioData - audio data to write to the device
      Returns:
      true of the write completed successfully, false if the write was cancelled.

    • write

      public boolean write(byte[] bytes, int offset, int size)
      Writes the given bytes to the audio stream
      Specified by:
      write in interface AudioPlayer
      Parameters:
      bytes - audio data to write to the device
      offset - the offset into the buffer
      size - the size into the buffer
      Returns:
      true of the write completed successfully, false if the write was cancelled.

    • toString

      public String toString()
      Returns the name of this audioplayer
      Overrides:
      toString in class Object
      Returns:
      the name of the audio player

    • showMetrics

      public void showMetrics()
      Shows metrics for this audio player
      Specified by:
      showMetrics in interface AudioPlayer