Package ptolemy.actor.lib.javasound

Class AudioWriteBuffer

  • All Implemented Interfaces:
    java.lang.Cloneable, Actor, Executable, FiringsRecordable, Initializable, TypedActor, Changeable, Debuggable, DebugListener, Derivable, Instantiable, ModelErrorHandler, MoMLExportable, Moveable, Nameable
    public class AudioWriteBuffer
extends TypedAtomicActor
    This actor writes audio samples to a buffer and saves the buffer to a sound file on wrapup. In each iteration, if there is a token available on the data and address ports, then the data DoubleToken is written to the buffer location specified by the address IntToken. The valid address range is 0 to bufferLength -1. If an invalid address is specified, then the data value will be ignored and no data will be written. The audio samples in the buffer will be written to the sound file specified by the pathName parameter on wrapup.

    Any existing file with the same name will be silently overwritten. The data port is of type DoubleToken. Each DoubleToken read from the data port represents one sample of the audio data and should be in the range [-1.0, 1.0]. Any samples that are outside of this range will be hard-clipped to fall within this range before they are written to the sound file. Single channel (mono) audio is supported but stereo is not supported.

    The following parameters should be set to specify the format of the file to write. In all cases, an exception is thrown if an illegal parameter value is used. Note that if a parameter is changed while audio writing is active, all data written so far will be saved, and the sound file will be closed. Subsequent audio samples will then be written to a new sound file with the new parameter values.

    • pathName should be set to the name of the output file. Any existing file with the same name will be silently overwritten. Relative filenames are supported. The default value is "outfile.wav". The audio format to use is determined by the file extension. E.g., "outfile.wav" will create a WAV format file. The supported file formats are AU, WAV, and, AIFF. For example, to write samples to a Sun AU format file with the name "test.au" in the directory "c:\tmp", this parameter should be set to the value c:\tmp\test.au. To write samples to a file with name "test.au" in the current directory, this parameter should be set to the value test.au.
    • 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. Only single-channel audio is currently supported. This limitation will be removed in a future version of this actor.
    • sampleRate should be set to desired sample rate, in Hz. The DoubleTokens read in by this actor will be interpreted as having this sample rate. Allowable values are 8000, 11025, 22050, 44100, and 48000. The default value is 8000.
    • bitsPerSample should be set to desired bit resolution. Allowable values are 8 and 16. The default value is 16.

    There are security issues involved with accessing files and audio resources in applets. By default, applets are not allowed to write files. The .java.policy file may be modified to grant applets more privileges.

    FIXME: this should extend AudioWriter

    Since:
    Ptolemy II 2.0
    Version:
    $Id$
    Author:
    Brian K. Vogel
    Pt.AcceptedRating:
    Red (vogel)
    Pt.ProposedRating:
    Red (vogel)

    • Field Detail

      • address

        public TypedIOPort address
        The address port, which is a multiport.

      • data

        public TypedIOPort data
        The data port, which is a multiport.

      • bufferLength

        public Parameter bufferLength
        The length of the audio buffer to use. The default value is 8000.

      • overwrite

        public Parameter overwrite
        The write mode to use. If this parameter is set to true, then a write to a buffer element overwrites the old value in the buffer. Otherwise, a write adds the new value to the old value of the buffer element.

      • pathName

        public StringAttribute pathName
        The name of the file to write to. The default value of this parameter is "test.wav", which creates a file called test.wav in the current directory and writes samples to this file.

        The audio format to use is determined by the file extension. E.g., "outfile.wav" will create a WAV format file. The supported file formats are AU, WAV, and, AIFF.

        An exception will be occur if the path references an unsupported sound file.

      • sampleRate

        public Parameter sampleRate
        The desired sample rate to use, in Hz. Valid values include: 8000, 11025, 22050, 44100, and 48000. The default value of the sample rate is an IntToken equal to 8000.

        An exception will be thrown if an illegal value is used.

      • bitsPerSample

        public Parameter bitsPerSample
        The desired number of bits per sample. The default value is an IntToken equal to 16. Supported values are 8 and 16. An exception will be thrown if an illegal value is used.

      • channels

        public Parameter channels
        The number of audio channels to use. Supported values are 1 (single channel) and 2 (stereo). The default value is an IntToken equal to 1. An exception will be thrown if an illegal value is used.