Package ptolemy.actor.lib.javasound

Class AudioPlayer

  • All Implemented Interfaces:
    java.lang.Cloneable, Actor, Executable, FiringsRecordable, Initializable, TypedActor, Changeable, Debuggable, DebugListener, Derivable, Instantiable, ModelErrorHandler, MoMLExportable, Moveable, Nameable
    public class AudioPlayer
extends LiveSoundActor
    This actor reads audio samples and plays them.

    Specifically, the input stream that this actor reads is interpreted as consisting of audio samples. This actor writes this stream of audio samples to the audio output port of the computer, which typically consists of the computer speaker or the headphones output. The audio samples that are supplied to this actor should be doubles in the range [-1.0, 1.0]. Thus, the input port of this actor is of type DoubleToken. Any input tokens that are outside of the valid range will be hard-clipped to fall within the range [-1.0, 1.0] before they are written to the audio output port of the computer.

    This actor should be fired often enough to prevent underflow of the internal audio playback buffer. Underflow should be avoided, since it will result in audio discontinuities (heard as clicks) in the output. No exception will be thrown if underflow occurs.

    The following parameters should be set accordingly. In all cases, an exception is thrown if an illegal parameter value is used. Note that these parameters may be changed while audio capture is active. If this actor is used in conjunction with an AudioCapture actor, changing a parameter of this actor will cause the corresponding parameter value of the AudioCapture actor to automatically be set to the same value. This behavior is required because the AudioCapture and AudioPlayer actors both share access to the audio hardware, which is associated with a single sample rate, bit resolution, and number of channels.

    • sampleRate should be set to desired sample rate, in Hz. The default value is 8000. Allowable values are 8000, 11025, 22050, 44100, and 48000 Hz. Some sound cards support 96000 Hz operation, but this is not supported in Java.
    • bitsPerSample should be set to desired bit resolution. The default value is 16. Allowable values are 8 and 16. Some sound cards support 20 and 24 bit audio, but this is not supported in Java.
    • channels should be set to desired number of audio channels. Allowable values are 1 (for mono) and 2 (for stereo). The default value is 1. Some sound cards support more than two audio channels, but this is not supported in Java.

    If more than one AudioPlayer actor is used in model, the sounds produced by these actors will be interleaved. This may make sense, for example, if the actor is used in a ModalModel.

    Since:
    Ptolemy II 1.0
    Version:
    $Id$
    Author:
    Brian K. Vogel, Steve Neuendorffer
    See Also:
    LiveSound, AudioCapture, AudioReader, AudioWriter
    Pt.AcceptedRating:
    Yellow (chf)
    Pt.ProposedRating:
    Green (neuendor)