org.monte.media.mp3

Class MP3AudioInputStream

java.lang.Object

java.io.InputStream

javax.sound.sampled.AudioInputStream

org.monte.media.mp3.MP3AudioInputStream

All Implemented Interfaces:

Closeable, AutoCloseable

public class MP3AudioInputStream
extends AudioInputStream

AudioInputStream adapter for MP3ElementaryInputStream.

Unlike a regular audio input stream, an MP3 audio input stream can have a variable frame size and can change its encoding method in mid-stream. Therefore method getFormat can return different values for each frame, and mark/reset is not supported, and method getFrameLength can not return the total number of frames in the stream.

Version:

1.0.1 2011-03-18 Method read(byte[],int,int) must not read multiple frames of different sizes.
1.0 2011-01-01 Created.

Author:

Werner Randelshofer

Field Summary

Fields inherited from class javax.sound.sampled.AudioInputStream

format, frameLength, framePos, frameSize

Constructor Summary

Constructors

Constructor and Description
MP3AudioInputStream(File file) Creates an MP3AudioInputStream and reads the stream until the first frame is reached.
MP3AudioInputStream(InputStream in) Creates an MP3AudioInputStream and reads the stream until the first frame is reached.

Method Summary

Methods

Modifier and Type	Method and Description
int	available()
void	close()
AudioFormat	getFormat() Returns the format of the next frame.
long	getFrameLength() Returns -1 because we don't know how many frames the stream has.
void	mark(int readlimit)
boolean	markSupported()
int	read() Throws an IOException, because the frame size is greater than 1.
int	read(byte[] b, int off, int len) Reads some number of bytes from the audio input stream and stores them into the buffer array b.
void	reset()
long	skip(long n)

Methods inherited from class javax.sound.sampled.AudioInputStream

read

Methods inherited from class java.lang.Object

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

Constructor Detail

MP3AudioInputStream

public MP3AudioInputStream(File file)
                    throws IOException

Creates an MP3AudioInputStream and reads the stream until the first frame is reached.

Parameters:

file - A File.

Throws:

IOException - if the file does not contain an MP3 elementary stream.

MP3AudioInputStream

public MP3AudioInputStream(InputStream in)
                    throws IOException

Creates an MP3AudioInputStream and reads the stream until the first frame is reached.

Parameters:

in - An InputStream.

Throws:

IOException - if the stream does not contain an MP3 elementary stream.

Method Detail

available

public int available()
              throws IOException

Overrides:

available in class AudioInputStream

Throws:

IOException

getFormat

public AudioFormat getFormat()

Returns the format of the next frame. Returns null if the stream is not positioned inside a frame.

Overrides:

getFormat in class AudioInputStream

getFrameLength

public long getFrameLength()

Returns -1 because we don't know how many frames the stream has.

Overrides:

getFrameLength in class AudioInputStream

close

public void close()
           throws IOException

Specified by:

close in interface Closeable

Specified by:

close in interface AutoCloseable

Overrides:

close in class AudioInputStream

Throws:

IOException

read

public int read()
         throws IOException

Throws an IOException, because the frame size is greater than 1.

Overrides:

read in class AudioInputStream

Throws:

IOException

read

public int read(byte[] b,
       int off,
       int len)
         throws IOException

Reads some number of bytes from the audio input stream and stores them into the buffer array b. The number of bytes actually read is returned as an integer. This method blocks until input data is available, the end of the stream is detected, or an exception is thrown. This method will always read an integral number of frames. If the length of the array is not an integral number of frames, a maximum of b.length - (b.length % frameSize) bytes will be read.

Overrides:

read in class AudioInputStream

Returns:

Returns the total number of bytes read into the buffer, or -1 if there is no more data because the end of the stream has been reached.

Throws:

IOException

skip

public long skip(long n)
          throws IOException

Overrides:

skip in class AudioInputStream

Throws:

IOException

mark

public void mark(int readlimit)

Overrides:

mark in class AudioInputStream

markSupported

public boolean markSupported()

Overrides:

markSupported in class AudioInputStream

reset

public void reset()
           throws IOException

Overrides:

reset in class AudioInputStream

Throws:

IOException