Package javaforce.codec.speex

Class OggCrc

java.lang.Object

javaforce.codec.speex.OggCrc

public class OggCrc
extends Object

Calculates the CRC checksum for Ogg packets.

Ogg uses the same generator polynomial as ethernet, although with an unreflected alg and an init/final of 0, not 0xffffffff.

Version:

$Revision$

Author:

Jim Lawrence, helloNetwork.com, Marc Gimpel, Wimba S.A. (mgimpel@horizonwimba.com)

Constructor Summary

Constructors

Constructor	Description
OggCrc()

Method Summary

Modifier and Type	Method	Description
static int	checksum(int crc, byte[] data, int offset, int length)	Calculates the checksum on the given data, from the give offset and for the given length, using the given initial value.

Methods inherited from class java.lang.Object

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

Constructor Details

OggCrc

public OggCrc()

Method Details

checksum

public static int checksum(int crc,
 byte[] data,
 int offset,
 int length)

Calculates the checksum on the given data, from the give offset and for the given length, using the given initial value. This allows on to calculate the checksum iteratively, by reinjecting the last returned value as the initial value when the function is called for the next data chunk. The initial value should be 0 for the first iteration.

Parameters:

crc - - the initial value

data - - the data

offset - - the offset at which to start calculating the checksum.

length - - the length of data over which to calculate the checksum.

Returns:

the checksum.