hu.netmind.ogg
Class Page

java.lang.Object
  hu.netmind.ogg.Page

All Implemented Interfaces:

java.io.Serializable

public class Page
extends java.lang.Object
implements java.io.Serializable

This class represents a page in the ogg format, and gives low-level manipulator access to all fields. Constitency checks are also implemented to help building a good ogg page.

See Also:

Serialized Form

Field Summary

static FastCrc	fastCrc
static byte[]	OGG_CAPTURE_PATTERN

Method Summary

Packet	add(Packet packet) Add a packet to this page.
boolean	checkCapturePattern() Check capture pattern for ogg.
boolean	checkCrcChecksum() Check the crc number in this page.
long	computeCrcChecksum() Compute crc number for this page.
static Page	fromByteArray(byte[] b) Create page from a byte array.
static Page	fromByteStream(java.io.InputStream stream) Convert a serialized page from a byte stream to a page object.
int	getBitstreamSerialNumber()
byte[]	getCapturePattern()
int	getCrcChecksum()
long	getGranulePosition()
byte	getHeaderType()
int	getPacketCount()
java.util.Collection	getPackets() Get all packets in this page.
int	getPageSegments()
int	getPageSequenceNumber()
byte	getVersion()
boolean	isBos() Return whether this a begin of stream page.
boolean	isContinued() Return whether this page's data belong to the previous packet (that packet is continued in this page).
boolean	isEos() Return whether this an end of stream page.
boolean	isFull() Returns whether this page is full, or not. Note:Page is also considered full, if it is a bos page, and one packet is inserted.
void	setBitstreamSerialNumber(int bitstreamSerialNumber)
void	setBos() Set the bos flag.
void	setCapturePattern(byte[] capturePattern)
void	setContinued() Set the continued flag.
void	setCrcChecksum(int crcChecksum)
void	setEos() Set the eos flag.
void	setGranulePosition(long granulePosition)
void	setHeaderType(byte headerType)
void	setPageSequenceNumber(int pageSequenceNumber)
void	setVersion(byte version)
int	size() The size of data residing in this page.
byte[]	toByteArray() Convert this page into a byte array.
java.lang.String	toString() Write human readable representation.

Methods inherited from class java.lang.Object

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

Field Detail

OGG_CAPTURE_PATTERN

public static final byte[] OGG_CAPTURE_PATTERN

fastCrc

public static FastCrc fastCrc

Method Detail

checkCapturePattern

public boolean checkCapturePattern()

Check capture pattern for ogg.

Returns:

True, if this is an ogg capture pattern, false otherwise.

getCapturePattern

public byte[] getCapturePattern()

setCapturePattern

public void setCapturePattern(byte[] capturePattern)

getVersion

public byte getVersion()

setVersion

public void setVersion(byte version)

isBos

public boolean isBos()

Return whether this a begin of stream page.

Returns:

True, if this page is a bos.

isEos

public boolean isEos()

Return whether this an end of stream page.

Returns:

True, if this page is an eos.

setBos

public void setBos()

Set the bos flag.

setEos

public void setEos()

Set the eos flag.

setContinued

public void setContinued()

Set the continued flag.

isContinued

public boolean isContinued()

Return whether this page's data belong to the previous packet (that packet is continued in this page).

Returns:

True, if this data belongs to the previous packet, false if this is a new packet.

getHeaderType

public byte getHeaderType()

setHeaderType

public void setHeaderType(byte headerType)

getGranulePosition

public long getGranulePosition()

setGranulePosition

public void setGranulePosition(long granulePosition)

getBitstreamSerialNumber

public int getBitstreamSerialNumber()

setBitstreamSerialNumber

public void setBitstreamSerialNumber(int bitstreamSerialNumber)

getPageSequenceNumber

public int getPageSequenceNumber()

setPageSequenceNumber

public void setPageSequenceNumber(int pageSequenceNumber)

computeCrcChecksum

public long computeCrcChecksum()
                        throws java.io.IOException

Compute crc number for this page. Note, that crc is generated for the whole page, so all data subsequently modifed will result in a bad crc code.

Returns:

The crc value, which is also set.

Throws:

java.io.IOException - If an error occurs buring converting to byte.

checkCrcChecksum

public boolean checkCrcChecksum()
                         throws java.io.IOException

Check the crc number in this page.

Returns:

True, if crc matches the content of page, false otherwise.

Throws:

java.io.IOException - If an error occurs buring converting to byte.

getCrcChecksum

public int getCrcChecksum()

setCrcChecksum

public void setCrcChecksum(int crcChecksum)

size

public int size()

The size of data residing in this page.

getPageSegments

public int getPageSegments()

isFull

public boolean isFull()

Returns whether this page is full, or not.
Note:Page is also considered full, if it is a bos page, and one packet is inserted. (Per specification the bos page can only contain a single packet)

Returns:

True, if the page is full, no more data will be inserted, and subsequent calls to add() will only return the packet.

getPackets

public java.util.Collection getPackets()

Get all packets in this page. Note, that the first packet may be a part of the packet in the previous page.

getPacketCount

public int getPacketCount()

add

public Packet add(Packet packet)

Add a packet to this page.

Returns:

A packet chunk. If the packet did not fit into this page, this packet chunk is returned. If the page is full, the original packet is returned. If the full packet is inserted, null is returned.
Note that this method only adds the packet, and maintains the segment counter, it does not manipulate any other data, such as the crc, or type indicator bits.

toByteArray

public byte[] toByteArray()
                   throws java.io.IOException

Convert this page into a byte array.

Returns:

The byte array representing this page.

Throws:

java.io.IOException - If the byte array could not be assembled.

fromByteArray

public static Page fromByteArray(byte[] b)
                          throws java.io.IOException

Create page from a byte array.

Parameters:

b - The byte array representing the page.

Throws:

java.io.IOException - If the byte array operations fail.

fromByteStream

public static Page fromByteStream(java.io.InputStream stream)
                           throws java.io.IOException

Convert a serialized page from a byte stream to a page object. This method searches for the next occurence of 'OggS' in the stream, then reads that as a page. The page may still be inconsitent, call checkCrcChecksum() to verify page integrity.

Parameters:

stream - The stream to read.

Returns:

The page object, or null, if stream contained no valid pages.

Throws:

java.io.IOException - If an I/O error occured.

toString

public java.lang.String toString()

Write human readable representation.

Overrides:

toString in class java.lang.Object