Class FilteredAudioInputStream

  • All Implemented Interfaces:
    java.io.Closeable, java.lang.AutoCloseable
    Direct Known Subclasses:
    Pcm2SpeexAudioInputStream, Speex2PcmAudioInputStream

    public abstract class FilteredAudioInputStream
    extends javax.sound.sampled.AudioInputStream
    A FilteredAudioInputStream is an AudioInputStream with buffers to facilitate transcoding the audio. A first byte array can buffer the data from the underlying inputstream until sufficient data for transcoding is present. A second byte array can hold the transcoded audio data, ready to be read out by the stream user.
    Version:
    $Revision: 1.2 $
    Author:
    Marc Gimpel, Wimba S.A. (mgimpel@horizonwimba.com)
    • Field Summary

      Fields 
      Modifier and Type Field Description
      protected byte[] buf
      The internal buffer array where the data is stored.
      protected int count
      The index one greater than the index of the last valid byte in the buffer.
      static int DEFAULT_BUFFER_SIZE
      The default size of the buffer.
      protected java.io.InputStream in
      The underlying inputStream.
      protected int marklimit
      The maximum read ahead allowed after a call to the mark method before subsequent calls to the reset method fail.
      protected int markpos
      The value of the pos field at the time the last mark method was called.
      protected int pos
      The current position in the buffer.
      protected byte[] prebuf
      The internal buffer array where the unfiltered data is temporarily stored.
      protected int precount
      The index one greater than the index of the last valid byte in the unfiltered data buffer.
      protected int prepos
      The current position in the unfiltered data buffer.
      private byte[] single
      Array of size 1, used by the read method to read just 1 byte.
      • Fields inherited from class javax.sound.sampled.AudioInputStream

        format, frameLength, framePos, frameSize
    • Constructor Summary

      Constructors 
      Constructor Description
      FilteredAudioInputStream​(java.io.InputStream in, javax.sound.sampled.AudioFormat format, long length)
      Creates a FilteredAudioInputStream and saves its argument, the input stream in, for later use.
      FilteredAudioInputStream​(java.io.InputStream in, javax.sound.sampled.AudioFormat format, long length, int size)
      Creates a FilteredAudioInputStream with the specified buffer size, and saves its argument, the inputstream in for later use.
      FilteredAudioInputStream​(java.io.InputStream in, javax.sound.sampled.AudioFormat format, long length, int size, int presize)
      Creates a FilteredAudioInputStream with the specified buffer size, and saves its argument, the inputstream in for later use.
    • Method Summary

      All Methods Instance Methods Concrete Methods 
      Modifier and Type Method Description
      int available()
      Returns the number of bytes that can be read from this inputstream without blocking.
      protected void checkIfStillOpen()
      Check to make sure that this stream has not been closed
      void close()
      Closes this input stream and releases any system resources associated with the stream.
      protected void fill()
      Fills the buffer with more data, taking into account shuffling and other tricks for dealing with marks.
      protected void makeSpace()
      Free up some space in the buffers.
      void mark​(int readlimit)
      See the general contract of the mark method of InputStream.
      boolean markSupported()
      Tests if this input stream supports the mark and reset methods.
      int read()
      See the general contract of the read method of InputStream.
      int read​(byte[] b, int off, int len)
      Reads bytes from this byte-input stream into the specified byte array, starting at the given offset.
      void reset()
      See the general contract of the reset method of InputStream.
      long skip​(long n)
      See the general contract of the skip method of InputStream.
      • Methods inherited from class javax.sound.sampled.AudioInputStream

        getFormat, getFrameLength, read
      • Methods inherited from class java.io.InputStream

        nullInputStream, readAllBytes, readNBytes, readNBytes, transferTo
      • Methods inherited from class java.lang.Object

        clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait
    • Field Detail

      • DEFAULT_BUFFER_SIZE

        public static final int DEFAULT_BUFFER_SIZE
        The default size of the buffer.
        See Also:
        Constant Field Values
      • in

        protected java.io.InputStream in
        The underlying inputStream.
      • buf

        protected byte[] buf
        The internal buffer array where the data is stored. When necessary, it may be replaced by another array of a different size.
      • count

        protected int count
        The index one greater than the index of the last valid byte in the buffer. This value is always in the range 0 through buf.length; elements buf[0] through buf[count-1] contain buffered input data obtained and filtered from the underlying inputstream.
      • pos

        protected int pos
        The current position in the buffer. This is the index of the next character to be read from the buf array.

        This value is always in the range 0 through count. If it is less than count, then buf[pos] is the next byte to be supplied as input. If it is equal to count, then the next read or skip operation will require more bytes to be read and filtered from the underlying inputstream.

        See Also:
        buf
      • markpos

        protected int markpos
        The value of the pos field at the time the last mark method was called.

        This value is always in the range -1 through pos. If there is no marked position in the inputstream, this field is -1. If there is a marked position in the inputstream, then buf[markpos] is the first byte to be supplied as input after a reset operation. If markpos is not -1, then all bytes from positions buf[markpos] through buf[pos-1] must remain in the buffer array (though they may be moved to another place in the buffer array, with suitable adjustments to the values of count, pos, and markpos); they may not be discarded unless and until the difference between pos and markpos exceeds marklimit.

        See Also:
        mark(int), pos
      • marklimit

        protected int marklimit
        The maximum read ahead allowed after a call to the mark method before subsequent calls to the reset method fail. Whenever the difference between pos and markpos exceeds marklimit, then the mark may be dropped by setting markpos to -1.
        See Also:
        mark(int), reset()
      • single

        private final byte[] single
        Array of size 1, used by the read method to read just 1 byte.
      • prebuf

        protected byte[] prebuf
        The internal buffer array where the unfiltered data is temporarily stored.
      • precount

        protected int precount
        The index one greater than the index of the last valid byte in the unfiltered data buffer. This value is always in the range 0 through prebuf.length; elements prebuf[0] through prebuf[count-1] contain buffered input data obtained from the underlying input stream.
      • prepos

        protected int prepos
        The current position in the unfiltered data buffer. This is the index of the next character to be read from the prebuf array.

        This value is always in the range 0 through precount. If it is less than precount, then prebuf[pos] is the next byte to be supplied as input. If it is equal to precount, then the next read or skip operation will require more bytes to be read from the contained inputstream.

        See Also:
        prebuf
    • Constructor Detail

      • FilteredAudioInputStream

        public FilteredAudioInputStream​(java.io.InputStream in,
                                        javax.sound.sampled.AudioFormat format,
                                        long length)
        Creates a FilteredAudioInputStream and saves its argument, the input stream in, for later use. An internal buffer array is created and stored in buf.
        Parameters:
        in - the underlying input stream.
        format - the format of this stream's audio data.
        length - the length in sample frames of the data in this stream.
        Throws:
        java.lang.IllegalArgumentException - if size <= 0 or presize <= 0.
      • FilteredAudioInputStream

        public FilteredAudioInputStream​(java.io.InputStream in,
                                        javax.sound.sampled.AudioFormat format,
                                        long length,
                                        int size)
        Creates a FilteredAudioInputStream with the specified buffer size, and saves its argument, the inputstream in for later use. An internal buffer array of length size is created and stored in buf.
        Parameters:
        in - the underlying input stream.
        format - the format of this stream's audio data.
        length - the length in sample frames of the data in this stream.
        size - the buffer sizes.
        Throws:
        java.lang.IllegalArgumentException - if size <= 0.
      • FilteredAudioInputStream

        public FilteredAudioInputStream​(java.io.InputStream in,
                                        javax.sound.sampled.AudioFormat format,
                                        long length,
                                        int size,
                                        int presize)
        Creates a FilteredAudioInputStream with the specified buffer size, and saves its argument, the inputstream in for later use. An internal buffer array of length size is created and stored in buf.
        Parameters:
        in - the underlying input stream.
        format - the format of this stream's audio data.
        length - the length in sample frames of the data in this stream.
        size - the buffer size.
        presize - the prebuffer size.
        Throws:
        java.lang.IllegalArgumentException - if size <= 0 or presize <= 0.
    • Method Detail

      • checkIfStillOpen

        protected void checkIfStillOpen()
                                 throws java.io.IOException
        Check to make sure that this stream has not been closed
        Throws:
        java.io.IOException
      • fill

        protected void fill()
                     throws java.io.IOException
        Fills the buffer with more data, taking into account shuffling and other tricks for dealing with marks. Assumes that it is being called by a synchronized method. This method also assumes that all data has already been read in, hence pos > count.
        Throws:
        java.io.IOException
      • makeSpace

        protected void makeSpace()
        Free up some space in the buffers.
      • read

        public int read()
                 throws java.io.IOException
        See the general contract of the read method of InputStream.
        Overrides:
        read in class javax.sound.sampled.AudioInputStream
        Returns:
        the next byte of data, or -1 if the end of the stream is reached.
        Throws:
        java.io.IOException - if an I/O error occurs.
        See Also:
        in
      • read

        public int read​(byte[] b,
                        int off,
                        int len)
                 throws java.io.IOException
        Reads bytes from this byte-input stream into the specified byte array, starting at the given offset.

        This method implements the general contract of the corresponding read method of the InputStream class. As an additional convenience, it attempts to read as many bytes as possible by repeatedly invoking the read method of the underlying stream. This iterated read continues until one of the following conditions becomes true:

        • The specified number of bytes have been read,
        • The read method of the underlying stream returns -1, indicating end-of-file, or
        • The available method of the underlying stream returns zero, indicating that further input requests would block.
        If the first read on the underlying stream returns -1 to indicate end-of-file then this method returns -1. Otherwise this method returns the number of bytes actually read.

        Subclasses of this class are encouraged, but not required, to attempt to read as many bytes as possible in the same fashion.

        Overrides:
        read in class javax.sound.sampled.AudioInputStream
        Parameters:
        b - destination buffer.
        off - offset at which to start storing bytes.
        len - maximum number of bytes to read.
        Returns:
        the number of bytes read, or -1 if the end of the stream has been reached.
        Throws:
        java.io.IOException - if an I/O error occurs.
      • skip

        public long skip​(long n)
                  throws java.io.IOException
        See the general contract of the skip method of InputStream.
        Overrides:
        skip in class javax.sound.sampled.AudioInputStream
        Parameters:
        n - the number of bytes to be skipped.
        Returns:
        the actual number of bytes skipped.
        Throws:
        java.io.IOException - if an I/O error occurs.
      • available

        public int available()
                      throws java.io.IOException
        Returns the number of bytes that can be read from this inputstream without blocking.

        The available method of FilteredAudioInputStream returns the sum of the the number of bytes remaining to be read in the buffer (count - pos). The result of calling the available method of the underlying inputstream is not used, as this data will have to be filtered, and thus may not be the same size after processing (although subclasses that do the filtering should override this method and use the amount of data available in the underlying inputstream).

        Overrides:
        available in class javax.sound.sampled.AudioInputStream
        Returns:
        the number of bytes that can be read from this inputstream without blocking.
        Throws:
        java.io.IOException - if an I/O error occurs.
        See Also:
        in
      • mark

        public void mark​(int readlimit)
        See the general contract of the mark method of InputStream.
        Overrides:
        mark in class javax.sound.sampled.AudioInputStream
        Parameters:
        readlimit - the maximum limit of bytes that can be read before the mark position becomes invalid.
        See Also:
        reset()
      • reset

        public void reset()
                   throws java.io.IOException
        See the general contract of the reset method of InputStream.

        If markpos is -1 (no mark has been set or the mark has been invalidated), an IOException is thrown. Otherwise, pos is set equal to markpos.

        Overrides:
        reset in class javax.sound.sampled.AudioInputStream
        Throws:
        java.io.IOException - if this stream has not been marked or if the mark has been invalidated.
        See Also:
        mark(int)
      • markSupported

        public boolean markSupported()
        Tests if this input stream supports the mark and reset methods. The markSupported method of FilteredAudioInputStream returns true.
        Overrides:
        markSupported in class javax.sound.sampled.AudioInputStream
        Returns:
        a boolean indicating if this stream type supports the mark and reset methods.
        See Also:
        mark(int), reset()
      • close

        public void close()
                   throws java.io.IOException
        Closes this input stream and releases any system resources associated with the stream.
        Specified by:
        close in interface java.lang.AutoCloseable
        Specified by:
        close in interface java.io.Closeable
        Overrides:
        close in class javax.sound.sampled.AudioInputStream
        Throws:
        java.io.IOException - if an I/O error occurs.