javazoom.jl.decoder
Class Bitstream

java.lang.Object
  javazoom.jl.decoder.Bitstream

All Implemented Interfaces:

BitstreamErrors, JavaLayerErrors

public final class Bitstream
extends java.lang.Object
implements BitstreamErrors

The Bistream class is responsible for parsing an MPEG audio bitstream. REVIEW: much of the parsing currently occurs in the various decoders. This should be moved into this class and associated inner classes.

Field Summary

Fields inherited from interface javazoom.jl.decoder.BitstreamErrors

BITSTREAM_LAST, INVALIDFRAME, STREAM_EOF, STREAM_ERROR, UNEXPECTED_EOF, UNKNOWN_ERROR, UNKNOWN_SAMPLE_RATE

Fields inherited from interface javazoom.jl.decoder.JavaLayerErrors

BITSTREAM_ERROR, DECODER_ERROR

Constructor Summary

Bitstream(java.io.InputStream in)
Construct a IBitstream that reads data from a given InputStream.

Method Summary

void	close() Close the Bitstream.
void	closeFrame() Close MP3 frame.
int	get_bits(int number_of_bits) Read bits from buffer into the lower bits of an unsigned int.
java.io.InputStream	getRawID3v2() Return raw ID3v2 frames + header.
int	header_pos() Return position of the first audio header.
boolean	isSyncCurrentPosition(int syncmode) Determines if the next 4 bytes of the stream represent a frame header.
boolean	isSyncMark(int headerstring, int syncmode, int word)
protected BitstreamException	newBitstreamException(int errorcode)
protected BitstreamException	newBitstreamException(int errorcode, java.lang.Throwable throwable)
int	readBits(int n)
int	readCheckedBits(int n)
Header	readFrame() Reads and parses the next frame from the input source.
void	unreadFrame() Unreads the bytes read from the frame.

Methods inherited from class java.lang.Object

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

Constructor Detail

Bitstream

public Bitstream(java.io.InputStream in)

Construct a IBitstream that reads data from a given InputStream.

Parameters:

in - The InputStream to read from.

Method Detail

header_pos

public int header_pos()

Return position of the first audio header.

Returns:

size of ID3v2 tag frames.

getRawID3v2

public java.io.InputStream getRawID3v2()

Return raw ID3v2 frames + header.

Returns:

ID3v2 InputStream or null if ID3v2 frames are not available.

close

public void close()
           throws BitstreamException

Close the Bitstream.

Throws:

BitstreamException

readFrame

public Header readFrame()
                 throws BitstreamException

Reads and parses the next frame from the input source.

Returns:

the Header describing details of the frame read, or null if the end of the stream has been reached.

Throws:

BitstreamException

unreadFrame

public void unreadFrame()
                 throws BitstreamException

Unreads the bytes read from the frame.

Throws:

BitstreamException

closeFrame

public void closeFrame()

Close MP3 frame.

isSyncCurrentPosition

public boolean isSyncCurrentPosition(int syncmode)
                              throws BitstreamException

Determines if the next 4 bytes of the stream represent a frame header.

Throws:

BitstreamException

readBits

public int readBits(int n)

readCheckedBits

public int readCheckedBits(int n)

newBitstreamException

protected BitstreamException newBitstreamException(int errorcode)

newBitstreamException

protected BitstreamException newBitstreamException(int errorcode,
                                                   java.lang.Throwable throwable)

isSyncMark

public boolean isSyncMark(int headerstring,
                          int syncmode,
                          int word)

get_bits

public int get_bits(int number_of_bits)

Read bits from buffer into the lower bits of an unsigned int. The LSB contains the latest read bit of the stream. (1 <= number_of_bits <= 16)