pgbennett.id3
Class XingVBRHeader

java.lang.Object
  pgbennett.id3.XingVBRHeader

public class XingVBRHeader
extends java.lang.Object

Reads information from a Xing info header. Thanks to the Scilla project (http://www.xs4all.nl/~rwvtveer/scilla/) for code ideas.

Version History

1.2.1 - 2002.1023 by gruni

-Made Sourcecode compliant to the Sun CodingConventions

1.2 - 2002.0203 by helliker

-Uses the file size if no byteSize is present in header.

1.1 - 2002.0121 by helliker

-Initial version.

Constructor Summary

XingVBRHeader(java.io.RandomAccessFile raf, long offset, int layer, int mpegVersion, int sampleRate, int channelMode)
Looks for a Xing VBR header in the file.

Method Summary

int	getAvgBitrate() Returns the average bit rate of the mpeg file if a Xing header exists and -1 otherwise.
int	getLength() Returns the length (in bytes) of this Xing VBR header.
int	getNumBytes() Returns the number of data bytes in the mpeg frames.
int	getNumFrames() Returns the number of MPEG frames in the file passed to the constructor.
int	getPlayingTime() Returns the calculated playing time of the mpeg file if a Xing header exists and -1 otherwise.
byte[]	getTOC() Returns the toc used to seek to an area of this VBR file.
int	getVBRScale() Returns the VBR scale used to generate this VBR file.
boolean	headerExists() Returns true if a Xing VBR header was found in the file passed to the constructor.
java.lang.String	toString() Return a string representation of this object.

Methods inherited from class java.lang.Object

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

Constructor Detail

XingVBRHeader

public XingVBRHeader(java.io.RandomAccessFile raf,
                     long offset,
                     int layer,
                     int mpegVersion,
                     int sampleRate,
                     int channelMode)
              throws java.io.IOException,
                     CorruptHeaderException

Looks for a Xing VBR header in the file. If it is found then that means this is a variable bit rate file and all the data in the header will be parsed.

Parameters:

raf - the file to read from

offset - the location of the first mpeg frame

layer - the layer value read by the MPEGAudioFrameHeader

mpegVersion - the version value read by the MPEGAudioFrameHeader

sampleRate - the sample rate read by the MPEGAudioFrameHeader

channelMode - the channel mode read by the MPEGAudioFrameHeader

Throws:

java.io.IOException - if an error occurs

CorruptHeaderException - if an error occurs

Method Detail

headerExists

public boolean headerExists()

Returns true if a Xing VBR header was found in the file passed to the constructor.

Returns:

true if a Xinb VBR header was found

getNumFrames

public int getNumFrames()

Returns the number of MPEG frames in the file passed to the constructor. If a header is not found, -1 is returned.

Returns:

the number of MPEG frames

getNumBytes

public int getNumBytes()

Returns the number of data bytes in the mpeg frames. If a header is not found, -1 is returned.

Returns:

the number of data bytes in the mpeg frames

getVBRScale

public int getVBRScale()

Returns the VBR scale used to generate this VBR file. If a header is not found, -1 is returned.

Returns:

the VBR scale used to generate this VBR file

getTOC

public byte[] getTOC()

Returns the toc used to seek to an area of this VBR file. If a header is not found an empty array is returned.

Returns:

the toc used to seek to an area of this VBR file

getAvgBitrate

public int getAvgBitrate()

Returns the average bit rate of the mpeg file if a Xing header exists and -1 otherwise.

Returns:

the average bit rate (in kbps)

getPlayingTime

public int getPlayingTime()

Returns the calculated playing time of the mpeg file if a Xing header exists and -1 otherwise.

Returns:

the playing time (in seconds) of the mpeg file

toString

public java.lang.String toString()

Return a string representation of this object. Includes all information read in and computed.

Overrides:

toString in class java.lang.Object

Returns:

a string representation of this object

getLength

public int getLength()

Returns the length (in bytes) of this Xing VBR header.

Returns:

the length of this Xing VBR header