javax.sound.sampled

Class AudioInputStream

Implemented Interfaces:
AutoCloseable, Closeable

public class AudioInputStream
extends InputStream

This is an InputStream which is specialized for reading audio files. In particular it only allows operations to act on a multiple of the audio stream's frame size.
Since:
1.3

Field Summary

protected AudioFormat
format
The format of the audio stream.
protected long
frameLength
The length of the audio stream in frames.
protected long
framePos
The current frame position, starting from frame zero.
protected int
frameSize
The size of a frame in bytes.

Constructor Summary

AudioInputStream(InputStream is, AudioFormat fmt, long length)
Create a new AudioInputStream given an underlying InputStream, the audio format, and the length of the data in frames.
AudioInputStream(TargetDataLine line)
Create a new AudioInputStream given a TargetDataLine.

Method Summary

int
available()
Return the number of bytes available to be read from the underlying stream.
void
close()
Close the stream.
AudioFormat
getFormat()
Get the format associated with this stream.
long
getFrameLength()
Get the length of this stream in frames.
void
mark(int limit)
This method marks a position in the input to which the stream can be "reset" by calling the reset() method.
boolean
markSupported()
Return true if the underlying stream supports mark and reset, false otherwise.
int
read()
Read a single byte from the underlying stream.
int
read(byte[] buf)
This method reads bytes from a stream and stores them into a caller supplied buffer.
int
read(byte[] buf, int offset, int length)
This method read bytes from a stream and stores them into a caller supplied buffer.
void
reset()
This method resets a stream to the point where the mark() method was called.
long
skip(long n)
This method skips the specified number of bytes in the stream.

Methods inherited from class java.io.InputStream

available, close, mark, markSupported, read, read, read, reset, skip

Methods inherited from class java.lang.Object

clone, equals, extends Object> getClass, finalize, hashCode, notify, notifyAll, toString, wait, wait, wait

Field Details

format

protected AudioFormat format
The format of the audio stream.

frameLength

protected long frameLength
The length of the audio stream in frames.

framePos

protected long framePos
The current frame position, starting from frame zero.

frameSize

protected int frameSize
The size of a frame in bytes.

Constructor Details

AudioInputStream

public AudioInputStream(InputStream is,
                        AudioFormat fmt,
                        long length)
Create a new AudioInputStream given an underlying InputStream, the audio format, and the length of the data in frames. The frame size is taken from the format.
Parameters:
is - the underlying input stream
fmt - the format of the data
length - the length of the data in frames

AudioInputStream

public AudioInputStream(TargetDataLine line)
Create a new AudioInputStream given a TargetDataLine. The audio format and the frame size are taken from the line.
Parameters:
line - the TargetDataLine

Method Details

available

public int available()
            throws IOException
Return the number of bytes available to be read from the underlying stream. This wrapper method ensures that the result is always a multiple of the frame size.
Overrides:
available in interface InputStream

close

public void close()
            throws IOException
Close the stream.
Specified by:
close in interface Closeable
close in interface AutoCloseable
Overrides:
close in interface InputStream

getFormat

public AudioFormat getFormat()
Get the format associated with this stream.
Returns:
the AudioFormat

getFrameLength

public long getFrameLength()
Get the length of this stream in frames. Note that this may be AudioSystem#NOT_SPECIFIED.
Returns:
the length of the stream in frames

mark

public void mark(int limit)
This method marks a position in the input to which the stream can be "reset" by calling the reset() method. The parameter @code{readlimit} is the number of bytes that can be read from the stream after setting the mark before the mark becomes invalid. For example, if mark() is called with a read limit of 10, then when 11 bytes of data are read from the stream before the reset() method is called, then the mark is invalid and the stream object instance is not required to remember the mark.

This method does nothing in this class, but subclasses may override it to provide mark/reset functionality.

Overrides:
mark in interface InputStream
Parameters:

markSupported

public boolean markSupported()
Return true if the underlying stream supports mark and reset, false otherwise.
Overrides:
markSupported in interface InputStream

read

public int read()
            throws IOException
Read a single byte from the underlying stream. If the frame size is set, and is not one byte, an IOException will be thrown.
Overrides:
read in interface InputStream

read

public int read(byte[] buf)
            throws IOException
This method reads bytes from a stream and stores them into a caller supplied buffer. This method attempts to completely fill the buffer, but can return before doing so. The actual number of bytes read is returned as an int. A -1 is returned to indicate the end of the stream.

This method will block until some data can be read.

This method operates by calling an overloaded read method like so: read(b, 0, b.length)

Overrides:
read in interface InputStream
Parameters:
Returns:
The number of bytes read or -1 if end of stream.
Throws:
IOException - If an error occurs.

read

public int read(byte[] buf,
                int offset,
                int length)
            throws IOException
This method read bytes from a stream and stores them into a caller supplied buffer. It starts storing the data at index off into the buffer and attempts to read len bytes. This method can return before reading the number of bytes requested. The actual number of bytes read is returned as an int. A -1 is returned to indicate the end of the stream.

This method will block until some data can be read.

This method operates by calling the single byte read() method in a loop until the desired number of bytes are read. The read loop stops short if the end of the stream is encountered or if an IOException is encountered on any read operation except the first. If the first attempt to read a bytes fails, the IOException is allowed to propagate upward. And subsequent IOException is caught and treated identically to an end of stream condition. Subclasses can (and should if possible) override this method to provide a more efficient implementation.

Overrides:
read in interface InputStream
Parameters:
Returns:
The actual number of bytes read, or -1 if end of stream.
Throws:
IOException - If an error occurs.

reset

public void reset()
            throws IOException
This method resets a stream to the point where the mark() method was called. Any bytes that were read after the mark point was set will be re-read during subsequent reads.

This method always throws an IOException in this class, but subclasses can override this method if they provide mark/reset functionality.

Overrides:
reset in interface InputStream
Throws:
IOException - Always thrown for this class

skip

public long skip(long n)
            throws IOException
This method skips the specified number of bytes in the stream. It returns the actual number of bytes skipped, which may be less than the requested amount.

This method reads and discards bytes into a byte array until the specified number of bytes were skipped or until either the end of stream is reached or a read attempt returns a short count. Subclasses can override this metho to provide a more efficient implementation where one exists.

Overrides:
skip in interface InputStream
Parameters:
n - The requested number of bytes to skip
Returns:
The actual number of bytes skipped.
Throws:
IOException - If an error occurs

Copyright (C) 2005 Free Software Foundation, Inc. This file is part of GNU Classpath. GNU Classpath is free software; you can redistribute it and/or modify it under the terms of the GNU General Public License as published by the Free Software Foundation; either version 2, or (at your option) any later version. GNU Classpath is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for more details. You should have received a copy of the GNU General Public License along with GNU Classpath; see the file COPYING. If not, write to the Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA. Linking this library statically or dynamically with other modules is making a combined work based on this library. Thus, the terms and conditions of the GNU General Public License cover the whole combination. As a special exception, the copyright holders of this library give you permission to link this library with independent modules to produce an executable, regardless of the license terms of these independent modules, and to copy and distribute the resulting executable under terms of your choice, provided that you also meet, for each linked independent module, the terms and conditions of the license of that module. An independent module is a module which is not derived from or based on this library. If you modify this library, you may extend this exception to your version of the library, but you are not obligated to do so. If you do not wish to do so, delete this exception statement from your version.